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1 |
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2 /* pngrtran.c - transforms the data in a row for PNG readers |
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3 * |
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4 * Last changed in libpng 1.2.38 [July 16, 2009] |
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5 * Copyright (c) 1998-2009 Glenn Randers-Pehrson |
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6 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
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7 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
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8 * |
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9 * This code is released under the libpng license. |
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10 * For conditions of distribution and use, see the disclaimer |
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11 * and license in png.h |
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12 * |
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13 * This file contains functions optionally called by an application |
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14 * in order to tell libpng how to handle data when reading a PNG. |
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15 * Transformations that are used in both reading and writing are |
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16 * in pngtrans.c. |
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17 */ |
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18 |
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19 #define PNG_INTERNAL |
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20 #include "png.h" |
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21 #if defined(PNG_READ_SUPPORTED) |
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22 |
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23 /* Set the action on getting a CRC error for an ancillary or critical chunk. */ |
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24 void PNGAPI |
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25 png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) |
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26 { |
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27 png_debug(1, "in png_set_crc_action"); |
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28 /* Tell libpng how we react to CRC errors in critical chunks */ |
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29 if (png_ptr == NULL) |
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30 return; |
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31 switch (crit_action) |
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32 { |
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33 case PNG_CRC_NO_CHANGE: /* Leave setting as is */ |
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34 break; |
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35 |
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36 case PNG_CRC_WARN_USE: /* Warn/use data */ |
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37 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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38 png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; |
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39 break; |
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40 |
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41 case PNG_CRC_QUIET_USE: /* Quiet/use data */ |
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42 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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43 png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | |
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44 PNG_FLAG_CRC_CRITICAL_IGNORE; |
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45 break; |
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46 |
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47 case PNG_CRC_WARN_DISCARD: /* Not a valid action for critical data */ |
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48 png_warning(png_ptr, |
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49 "Can't discard critical data on CRC error."); |
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50 case PNG_CRC_ERROR_QUIT: /* Error/quit */ |
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51 |
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52 case PNG_CRC_DEFAULT: |
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53 default: |
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54 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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55 break; |
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56 } |
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57 |
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58 switch (ancil_action) |
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59 { |
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60 case PNG_CRC_NO_CHANGE: /* Leave setting as is */ |
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61 break; |
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62 |
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63 case PNG_CRC_WARN_USE: /* Warn/use data */ |
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64 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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65 png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; |
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66 break; |
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67 |
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68 case PNG_CRC_QUIET_USE: /* Quiet/use data */ |
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69 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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70 png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | |
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71 PNG_FLAG_CRC_ANCILLARY_NOWARN; |
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72 break; |
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73 |
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74 case PNG_CRC_ERROR_QUIT: /* Error/quit */ |
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75 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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76 png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; |
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77 break; |
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78 |
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79 case PNG_CRC_WARN_DISCARD: /* Warn/discard data */ |
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80 |
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81 case PNG_CRC_DEFAULT: |
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82 default: |
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83 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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84 break; |
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85 } |
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86 } |
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87 |
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88 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ |
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89 defined(PNG_FLOATING_POINT_SUPPORTED) |
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90 /* Handle alpha and tRNS via a background color */ |
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91 void PNGAPI |
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92 png_set_background(png_structp png_ptr, |
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93 png_color_16p background_color, int background_gamma_code, |
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94 int need_expand, double background_gamma) |
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95 { |
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96 png_debug(1, "in png_set_background"); |
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97 if (png_ptr == NULL) |
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98 return; |
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99 if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) |
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100 { |
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101 png_warning(png_ptr, "Application must supply a known background gamma"); |
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102 return; |
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103 } |
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104 |
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105 png_ptr->transformations |= PNG_BACKGROUND; |
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106 png_memcpy(&(png_ptr->background), background_color, |
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107 png_sizeof(png_color_16)); |
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108 png_ptr->background_gamma = (float)background_gamma; |
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109 png_ptr->background_gamma_type = (png_byte)(background_gamma_code); |
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110 png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0); |
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111 } |
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112 #endif |
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113 |
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114 #if defined(PNG_READ_16_TO_8_SUPPORTED) |
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115 /* Strip 16 bit depth files to 8 bit depth */ |
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116 void PNGAPI |
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117 png_set_strip_16(png_structp png_ptr) |
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118 { |
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119 png_debug(1, "in png_set_strip_16"); |
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120 if (png_ptr == NULL) |
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121 return; |
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122 png_ptr->transformations |= PNG_16_TO_8; |
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123 } |
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124 #endif |
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125 |
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126 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
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127 void PNGAPI |
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128 png_set_strip_alpha(png_structp png_ptr) |
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129 { |
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130 png_debug(1, "in png_set_strip_alpha"); |
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131 if (png_ptr == NULL) |
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132 return; |
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133 png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; |
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134 } |
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135 #endif |
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136 |
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137 #if defined(PNG_READ_DITHER_SUPPORTED) |
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138 /* Dither file to 8 bit. Supply a palette, the current number |
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139 * of elements in the palette, the maximum number of elements |
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140 * allowed, and a histogram if possible. If the current number |
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141 * of colors is greater then the maximum number, the palette will be |
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142 * modified to fit in the maximum number. "full_dither" indicates |
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143 * whether we need a dithering cube set up for RGB images, or if we |
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144 * simply are reducing the number of colors in a paletted image. |
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145 */ |
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146 |
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147 typedef struct png_dsort_struct |
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148 { |
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149 struct png_dsort_struct FAR * next; |
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150 png_byte left; |
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151 png_byte right; |
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152 } png_dsort; |
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153 typedef png_dsort FAR * png_dsortp; |
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154 typedef png_dsort FAR * FAR * png_dsortpp; |
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155 |
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156 void PNGAPI |
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157 png_set_dither(png_structp png_ptr, png_colorp palette, |
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158 int num_palette, int maximum_colors, png_uint_16p histogram, |
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159 int full_dither) |
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160 { |
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161 png_debug(1, "in png_set_dither"); |
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162 if (png_ptr == NULL) |
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163 return; |
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164 png_ptr->transformations |= PNG_DITHER; |
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165 |
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166 if (!full_dither) |
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167 { |
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168 int i; |
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169 |
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170 png_ptr->dither_index = (png_bytep)png_malloc(png_ptr, |
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171 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
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172 for (i = 0; i < num_palette; i++) |
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173 png_ptr->dither_index[i] = (png_byte)i; |
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174 } |
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175 |
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176 if (num_palette > maximum_colors) |
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177 { |
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178 if (histogram != NULL) |
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179 { |
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180 /* This is easy enough, just throw out the least used colors. |
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181 * Perhaps not the best solution, but good enough. |
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182 */ |
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183 |
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184 int i; |
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185 |
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186 /* Initialize an array to sort colors */ |
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187 png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr, |
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188 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
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189 |
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190 /* Initialize the dither_sort array */ |
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191 for (i = 0; i < num_palette; i++) |
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192 png_ptr->dither_sort[i] = (png_byte)i; |
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193 |
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194 /* Find the least used palette entries by starting a |
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195 * bubble sort, and running it until we have sorted |
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196 * out enough colors. Note that we don't care about |
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197 * sorting all the colors, just finding which are |
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198 * least used. |
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199 */ |
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200 |
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201 for (i = num_palette - 1; i >= maximum_colors; i--) |
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202 { |
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203 int done; /* To stop early if the list is pre-sorted */ |
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204 int j; |
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205 |
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206 done = 1; |
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207 for (j = 0; j < i; j++) |
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208 { |
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209 if (histogram[png_ptr->dither_sort[j]] |
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210 < histogram[png_ptr->dither_sort[j + 1]]) |
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211 { |
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212 png_byte t; |
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213 |
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214 t = png_ptr->dither_sort[j]; |
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215 png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1]; |
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216 png_ptr->dither_sort[j + 1] = t; |
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217 done = 0; |
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218 } |
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219 } |
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220 if (done) |
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221 break; |
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222 } |
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223 |
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224 /* Swap the palette around, and set up a table, if necessary */ |
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225 if (full_dither) |
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226 { |
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227 int j = num_palette; |
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228 |
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229 /* Put all the useful colors within the max, but don't |
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230 * move the others. |
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231 */ |
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232 for (i = 0; i < maximum_colors; i++) |
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233 { |
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234 if ((int)png_ptr->dither_sort[i] >= maximum_colors) |
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235 { |
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236 do |
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237 j--; |
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238 while ((int)png_ptr->dither_sort[j] >= maximum_colors); |
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239 palette[i] = palette[j]; |
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240 } |
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241 } |
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242 } |
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243 else |
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244 { |
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245 int j = num_palette; |
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246 |
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247 /* Move all the used colors inside the max limit, and |
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248 * develop a translation table. |
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249 */ |
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250 for (i = 0; i < maximum_colors; i++) |
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251 { |
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252 /* Only move the colors we need to */ |
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253 if ((int)png_ptr->dither_sort[i] >= maximum_colors) |
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254 { |
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255 png_color tmp_color; |
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256 |
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257 do |
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258 j--; |
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259 while ((int)png_ptr->dither_sort[j] >= maximum_colors); |
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260 |
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261 tmp_color = palette[j]; |
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262 palette[j] = palette[i]; |
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263 palette[i] = tmp_color; |
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264 /* Indicate where the color went */ |
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265 png_ptr->dither_index[j] = (png_byte)i; |
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266 png_ptr->dither_index[i] = (png_byte)j; |
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267 } |
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268 } |
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269 |
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270 /* Find closest color for those colors we are not using */ |
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271 for (i = 0; i < num_palette; i++) |
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272 { |
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273 if ((int)png_ptr->dither_index[i] >= maximum_colors) |
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274 { |
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275 int min_d, k, min_k, d_index; |
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276 |
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277 /* Find the closest color to one we threw out */ |
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278 d_index = png_ptr->dither_index[i]; |
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279 min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); |
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280 for (k = 1, min_k = 0; k < maximum_colors; k++) |
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281 { |
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282 int d; |
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283 |
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284 d = PNG_COLOR_DIST(palette[d_index], palette[k]); |
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285 |
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286 if (d < min_d) |
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287 { |
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288 min_d = d; |
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289 min_k = k; |
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290 } |
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291 } |
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292 /* Point to closest color */ |
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293 png_ptr->dither_index[i] = (png_byte)min_k; |
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294 } |
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295 } |
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296 } |
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297 png_free(png_ptr, png_ptr->dither_sort); |
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298 png_ptr->dither_sort = NULL; |
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299 } |
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300 else |
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301 { |
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302 /* This is much harder to do simply (and quickly). Perhaps |
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303 * we need to go through a median cut routine, but those |
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304 * don't always behave themselves with only a few colors |
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305 * as input. So we will just find the closest two colors, |
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306 * and throw out one of them (chosen somewhat randomly). |
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307 * [We don't understand this at all, so if someone wants to |
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308 * work on improving it, be our guest - AED, GRP] |
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309 */ |
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310 int i; |
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311 int max_d; |
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312 int num_new_palette; |
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313 png_dsortp t; |
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314 png_dsortpp hash; |
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315 |
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316 t = NULL; |
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317 |
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318 /* Initialize palette index arrays */ |
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319 png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, |
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320 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
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321 png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, |
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322 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
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323 |
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324 /* Initialize the sort array */ |
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325 for (i = 0; i < num_palette; i++) |
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326 { |
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327 png_ptr->index_to_palette[i] = (png_byte)i; |
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328 png_ptr->palette_to_index[i] = (png_byte)i; |
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329 } |
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330 |
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331 hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 * |
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332 png_sizeof(png_dsortp))); |
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333 png_memset(hash, 0, 769 * png_sizeof(png_dsortp)); |
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334 |
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335 num_new_palette = num_palette; |
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336 |
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337 /* Initial wild guess at how far apart the farthest pixel |
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338 * pair we will be eliminating will be. Larger |
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339 * numbers mean more areas will be allocated, Smaller |
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340 * numbers run the risk of not saving enough data, and |
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341 * having to do this all over again. |
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342 * |
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343 * I have not done extensive checking on this number. |
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344 */ |
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345 max_d = 96; |
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346 |
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347 while (num_new_palette > maximum_colors) |
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348 { |
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349 for (i = 0; i < num_new_palette - 1; i++) |
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350 { |
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351 int j; |
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352 |
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353 for (j = i + 1; j < num_new_palette; j++) |
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354 { |
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355 int d; |
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356 |
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357 d = PNG_COLOR_DIST(palette[i], palette[j]); |
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358 |
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359 if (d <= max_d) |
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360 { |
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361 |
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362 t = (png_dsortp)png_malloc_warn(png_ptr, |
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363 (png_uint_32)(png_sizeof(png_dsort))); |
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364 if (t == NULL) |
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365 break; |
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366 t->next = hash[d]; |
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367 t->left = (png_byte)i; |
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368 t->right = (png_byte)j; |
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369 hash[d] = t; |
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370 } |
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371 } |
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372 if (t == NULL) |
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373 break; |
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374 } |
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375 |
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376 if (t != NULL) |
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377 for (i = 0; i <= max_d; i++) |
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378 { |
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379 if (hash[i] != NULL) |
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380 { |
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381 png_dsortp p; |
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382 |
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383 for (p = hash[i]; p; p = p->next) |
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384 { |
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385 if ((int)png_ptr->index_to_palette[p->left] |
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386 < num_new_palette && |
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387 (int)png_ptr->index_to_palette[p->right] |
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388 < num_new_palette) |
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389 { |
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390 int j, next_j; |
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391 |
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392 if (num_new_palette & 0x01) |
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393 { |
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394 j = p->left; |
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395 next_j = p->right; |
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396 } |
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397 else |
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398 { |
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399 j = p->right; |
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400 next_j = p->left; |
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401 } |
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402 |
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403 num_new_palette--; |
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404 palette[png_ptr->index_to_palette[j]] |
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405 = palette[num_new_palette]; |
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406 if (!full_dither) |
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407 { |
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408 int k; |
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409 |
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410 for (k = 0; k < num_palette; k++) |
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411 { |
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412 if (png_ptr->dither_index[k] == |
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413 png_ptr->index_to_palette[j]) |
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414 png_ptr->dither_index[k] = |
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415 png_ptr->index_to_palette[next_j]; |
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416 if ((int)png_ptr->dither_index[k] == |
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417 num_new_palette) |
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418 png_ptr->dither_index[k] = |
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419 png_ptr->index_to_palette[j]; |
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420 } |
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421 } |
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422 |
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423 png_ptr->index_to_palette[png_ptr->palette_to_index |
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424 [num_new_palette]] = png_ptr->index_to_palette[j]; |
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425 png_ptr->palette_to_index[png_ptr->index_to_palette[j]] |
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426 = png_ptr->palette_to_index[num_new_palette]; |
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427 |
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428 png_ptr->index_to_palette[j] = (png_byte)num_new_palette; |
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429 png_ptr->palette_to_index[num_new_palette] = (png_byte)j; |
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430 } |
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431 if (num_new_palette <= maximum_colors) |
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432 break; |
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433 } |
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434 if (num_new_palette <= maximum_colors) |
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435 break; |
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436 } |
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437 } |
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438 |
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439 for (i = 0; i < 769; i++) |
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440 { |
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441 if (hash[i] != NULL) |
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442 { |
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443 png_dsortp p = hash[i]; |
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444 while (p) |
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445 { |
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446 t = p->next; |
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447 png_free(png_ptr, p); |
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448 p = t; |
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449 } |
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450 } |
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451 hash[i] = 0; |
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452 } |
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453 max_d += 96; |
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454 } |
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455 png_free(png_ptr, hash); |
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456 png_free(png_ptr, png_ptr->palette_to_index); |
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457 png_free(png_ptr, png_ptr->index_to_palette); |
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458 png_ptr->palette_to_index = NULL; |
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459 png_ptr->index_to_palette = NULL; |
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460 } |
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461 num_palette = maximum_colors; |
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462 } |
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463 if (png_ptr->palette == NULL) |
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464 { |
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465 png_ptr->palette = palette; |
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466 } |
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467 png_ptr->num_palette = (png_uint_16)num_palette; |
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468 |
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469 if (full_dither) |
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470 { |
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471 int i; |
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472 png_bytep distance; |
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473 int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS + |
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474 PNG_DITHER_BLUE_BITS; |
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475 int num_red = (1 << PNG_DITHER_RED_BITS); |
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476 int num_green = (1 << PNG_DITHER_GREEN_BITS); |
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477 int num_blue = (1 << PNG_DITHER_BLUE_BITS); |
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478 png_size_t num_entries = ((png_size_t)1 << total_bits); |
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479 png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr, |
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480 (png_uint_32)(num_entries * png_sizeof(png_byte))); |
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481 png_memset(png_ptr->palette_lookup, 0, num_entries * |
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482 png_sizeof(png_byte)); |
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483 |
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484 distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * |
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485 png_sizeof(png_byte))); |
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486 |
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487 png_memset(distance, 0xff, num_entries * png_sizeof(png_byte)); |
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488 |
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489 for (i = 0; i < num_palette; i++) |
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490 { |
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491 int ir, ig, ib; |
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492 int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS)); |
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493 int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS)); |
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494 int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS)); |
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495 |
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496 for (ir = 0; ir < num_red; ir++) |
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497 { |
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498 /* int dr = abs(ir - r); */ |
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499 int dr = ((ir > r) ? ir - r : r - ir); |
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500 int index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS)); |
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501 |
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502 for (ig = 0; ig < num_green; ig++) |
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503 { |
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504 /* int dg = abs(ig - g); */ |
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505 int dg = ((ig > g) ? ig - g : g - ig); |
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506 int dt = dr + dg; |
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507 int dm = ((dr > dg) ? dr : dg); |
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508 int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS); |
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509 |
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510 for (ib = 0; ib < num_blue; ib++) |
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511 { |
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512 int d_index = index_g | ib; |
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513 /* int db = abs(ib - b); */ |
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514 int db = ((ib > b) ? ib - b : b - ib); |
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515 int dmax = ((dm > db) ? dm : db); |
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516 int d = dmax + dt + db; |
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517 |
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518 if (d < (int)distance[d_index]) |
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519 { |
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520 distance[d_index] = (png_byte)d; |
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521 png_ptr->palette_lookup[d_index] = (png_byte)i; |
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522 } |
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523 } |
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524 } |
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525 } |
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526 } |
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527 |
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528 png_free(png_ptr, distance); |
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529 } |
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530 } |
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531 #endif |
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532 |
|
533 #if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED) |
|
534 /* Transform the image from the file_gamma to the screen_gamma. We |
|
535 * only do transformations on images where the file_gamma and screen_gamma |
|
536 * are not close reciprocals, otherwise it slows things down slightly, and |
|
537 * also needlessly introduces small errors. |
|
538 * |
|
539 * We will turn off gamma transformation later if no semitransparent entries |
|
540 * are present in the tRNS array for palette images. We can't do it here |
|
541 * because we don't necessarily have the tRNS chunk yet. |
|
542 */ |
|
543 void PNGAPI |
|
544 png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma) |
|
545 { |
|
546 png_debug(1, "in png_set_gamma"); |
|
547 if (png_ptr == NULL) |
|
548 return; |
|
549 if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) || |
|
550 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) || |
|
551 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) |
|
552 png_ptr->transformations |= PNG_GAMMA; |
|
553 png_ptr->gamma = (float)file_gamma; |
|
554 png_ptr->screen_gamma = (float)scrn_gamma; |
|
555 } |
|
556 #endif |
|
557 |
|
558 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
559 /* Expand paletted images to RGB, expand grayscale images of |
|
560 * less than 8-bit depth to 8-bit depth, and expand tRNS chunks |
|
561 * to alpha channels. |
|
562 */ |
|
563 void PNGAPI |
|
564 png_set_expand(png_structp png_ptr) |
|
565 { |
|
566 png_debug(1, "in png_set_expand"); |
|
567 if (png_ptr == NULL) |
|
568 return; |
|
569 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
|
570 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
571 } |
|
572 |
|
573 /* GRR 19990627: the following three functions currently are identical |
|
574 * to png_set_expand(). However, it is entirely reasonable that someone |
|
575 * might wish to expand an indexed image to RGB but *not* expand a single, |
|
576 * fully transparent palette entry to a full alpha channel--perhaps instead |
|
577 * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace |
|
578 * the transparent color with a particular RGB value, or drop tRNS entirely. |
|
579 * IOW, a future version of the library may make the transformations flag |
|
580 * a bit more fine-grained, with separate bits for each of these three |
|
581 * functions. |
|
582 * |
|
583 * More to the point, these functions make it obvious what libpng will be |
|
584 * doing, whereas "expand" can (and does) mean any number of things. |
|
585 * |
|
586 * GRP 20060307: In libpng-1.4.0, png_set_gray_1_2_4_to_8() was modified |
|
587 * to expand only the sample depth but not to expand the tRNS to alpha. |
|
588 */ |
|
589 |
|
590 /* Expand paletted images to RGB. */ |
|
591 void PNGAPI |
|
592 png_set_palette_to_rgb(png_structp png_ptr) |
|
593 { |
|
594 png_debug(1, "in png_set_palette_to_rgb"); |
|
595 if (png_ptr == NULL) |
|
596 return; |
|
597 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
|
598 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
599 } |
|
600 |
|
601 #if !defined(PNG_1_0_X) |
|
602 /* Expand grayscale images of less than 8-bit depth to 8 bits. */ |
|
603 void PNGAPI |
|
604 png_set_expand_gray_1_2_4_to_8(png_structp png_ptr) |
|
605 { |
|
606 png_debug(1, "in png_set_expand_gray_1_2_4_to_8"); |
|
607 if (png_ptr == NULL) |
|
608 return; |
|
609 png_ptr->transformations |= PNG_EXPAND; |
|
610 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
611 } |
|
612 #endif |
|
613 |
|
614 #if defined(PNG_1_0_X) || defined(PNG_1_2_X) |
|
615 /* Expand grayscale images of less than 8-bit depth to 8 bits. */ |
|
616 /* Deprecated as of libpng-1.2.9 */ |
|
617 void PNGAPI |
|
618 png_set_gray_1_2_4_to_8(png_structp png_ptr) |
|
619 { |
|
620 png_debug(1, "in png_set_gray_1_2_4_to_8"); |
|
621 if (png_ptr == NULL) |
|
622 return; |
|
623 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
|
624 } |
|
625 #endif |
|
626 |
|
627 |
|
628 /* Expand tRNS chunks to alpha channels. */ |
|
629 void PNGAPI |
|
630 png_set_tRNS_to_alpha(png_structp png_ptr) |
|
631 { |
|
632 png_debug(1, "in png_set_tRNS_to_alpha"); |
|
633 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
|
634 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
635 } |
|
636 #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */ |
|
637 |
|
638 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
639 void PNGAPI |
|
640 png_set_gray_to_rgb(png_structp png_ptr) |
|
641 { |
|
642 png_debug(1, "in png_set_gray_to_rgb"); |
|
643 png_ptr->transformations |= PNG_GRAY_TO_RGB; |
|
644 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
645 } |
|
646 #endif |
|
647 |
|
648 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
649 #if defined(PNG_FLOATING_POINT_SUPPORTED) |
|
650 /* Convert a RGB image to a grayscale of the same width. This allows us, |
|
651 * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. |
|
652 */ |
|
653 |
|
654 void PNGAPI |
|
655 png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red, |
|
656 double green) |
|
657 { |
|
658 int red_fixed = (int)((float)red*100000.0 + 0.5); |
|
659 int green_fixed = (int)((float)green*100000.0 + 0.5); |
|
660 if (png_ptr == NULL) |
|
661 return; |
|
662 png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed); |
|
663 } |
|
664 #endif |
|
665 |
|
666 void PNGAPI |
|
667 png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, |
|
668 png_fixed_point red, png_fixed_point green) |
|
669 { |
|
670 png_debug(1, "in png_set_rgb_to_gray"); |
|
671 if (png_ptr == NULL) |
|
672 return; |
|
673 switch(error_action) |
|
674 { |
|
675 case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY; |
|
676 break; |
|
677 |
|
678 case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; |
|
679 break; |
|
680 |
|
681 case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; |
|
682 } |
|
683 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
684 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
685 png_ptr->transformations |= PNG_EXPAND; |
|
686 #else |
|
687 { |
|
688 png_warning(png_ptr, |
|
689 "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED."); |
|
690 png_ptr->transformations &= ~PNG_RGB_TO_GRAY; |
|
691 } |
|
692 #endif |
|
693 { |
|
694 png_uint_16 red_int, green_int; |
|
695 if (red < 0 || green < 0) |
|
696 { |
|
697 red_int = 6968; /* .212671 * 32768 + .5 */ |
|
698 green_int = 23434; /* .715160 * 32768 + .5 */ |
|
699 } |
|
700 else if (red + green < 100000L) |
|
701 { |
|
702 red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L); |
|
703 green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L); |
|
704 } |
|
705 else |
|
706 { |
|
707 png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients"); |
|
708 red_int = 6968; |
|
709 green_int = 23434; |
|
710 } |
|
711 png_ptr->rgb_to_gray_red_coeff = red_int; |
|
712 png_ptr->rgb_to_gray_green_coeff = green_int; |
|
713 png_ptr->rgb_to_gray_blue_coeff = |
|
714 (png_uint_16)(32768 - red_int - green_int); |
|
715 } |
|
716 } |
|
717 #endif |
|
718 |
|
719 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ |
|
720 defined(PNG_LEGACY_SUPPORTED) || \ |
|
721 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) |
|
722 void PNGAPI |
|
723 png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr |
|
724 read_user_transform_fn) |
|
725 { |
|
726 png_debug(1, "in png_set_read_user_transform_fn"); |
|
727 if (png_ptr == NULL) |
|
728 return; |
|
729 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
|
730 png_ptr->transformations |= PNG_USER_TRANSFORM; |
|
731 png_ptr->read_user_transform_fn = read_user_transform_fn; |
|
732 #endif |
|
733 #ifdef PNG_LEGACY_SUPPORTED |
|
734 if (read_user_transform_fn) |
|
735 png_warning(png_ptr, |
|
736 "This version of libpng does not support user transforms"); |
|
737 #endif |
|
738 } |
|
739 #endif |
|
740 |
|
741 /* Initialize everything needed for the read. This includes modifying |
|
742 * the palette. |
|
743 */ |
|
744 void /* PRIVATE */ |
|
745 png_init_read_transformations(png_structp png_ptr) |
|
746 { |
|
747 png_debug(1, "in png_init_read_transformations"); |
|
748 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
749 if (png_ptr != NULL) |
|
750 #endif |
|
751 { |
|
752 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || defined(PNG_READ_SHIFT_SUPPORTED) \ |
|
753 || defined(PNG_READ_GAMMA_SUPPORTED) |
|
754 int color_type = png_ptr->color_type; |
|
755 #endif |
|
756 |
|
757 #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
758 |
|
759 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
760 /* Detect gray background and attempt to enable optimization |
|
761 * for gray --> RGB case |
|
762 * |
|
763 * Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or |
|
764 * RGB_ALPHA (in which case need_expand is superfluous anyway), the |
|
765 * background color might actually be gray yet not be flagged as such. |
|
766 * This is not a problem for the current code, which uses |
|
767 * PNG_BACKGROUND_IS_GRAY only to decide when to do the |
|
768 * png_do_gray_to_rgb() transformation. |
|
769 */ |
|
770 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && |
|
771 !(color_type & PNG_COLOR_MASK_COLOR)) |
|
772 { |
|
773 png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; |
|
774 } else if ((png_ptr->transformations & PNG_BACKGROUND) && |
|
775 !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && |
|
776 (png_ptr->transformations & PNG_GRAY_TO_RGB) && |
|
777 png_ptr->background.red == png_ptr->background.green && |
|
778 png_ptr->background.red == png_ptr->background.blue) |
|
779 { |
|
780 png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; |
|
781 png_ptr->background.gray = png_ptr->background.red; |
|
782 } |
|
783 #endif |
|
784 |
|
785 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && |
|
786 (png_ptr->transformations & PNG_EXPAND)) |
|
787 { |
|
788 if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */ |
|
789 { |
|
790 /* Expand background and tRNS chunks */ |
|
791 switch (png_ptr->bit_depth) |
|
792 { |
|
793 case 1: |
|
794 png_ptr->background.gray *= (png_uint_16)0xff; |
|
795 png_ptr->background.red = png_ptr->background.green |
|
796 = png_ptr->background.blue = png_ptr->background.gray; |
|
797 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
798 { |
|
799 png_ptr->trans_values.gray *= (png_uint_16)0xff; |
|
800 png_ptr->trans_values.red = png_ptr->trans_values.green |
|
801 = png_ptr->trans_values.blue = png_ptr->trans_values.gray; |
|
802 } |
|
803 break; |
|
804 |
|
805 case 2: |
|
806 png_ptr->background.gray *= (png_uint_16)0x55; |
|
807 png_ptr->background.red = png_ptr->background.green |
|
808 = png_ptr->background.blue = png_ptr->background.gray; |
|
809 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
810 { |
|
811 png_ptr->trans_values.gray *= (png_uint_16)0x55; |
|
812 png_ptr->trans_values.red = png_ptr->trans_values.green |
|
813 = png_ptr->trans_values.blue = png_ptr->trans_values.gray; |
|
814 } |
|
815 break; |
|
816 |
|
817 case 4: |
|
818 png_ptr->background.gray *= (png_uint_16)0x11; |
|
819 png_ptr->background.red = png_ptr->background.green |
|
820 = png_ptr->background.blue = png_ptr->background.gray; |
|
821 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
822 { |
|
823 png_ptr->trans_values.gray *= (png_uint_16)0x11; |
|
824 png_ptr->trans_values.red = png_ptr->trans_values.green |
|
825 = png_ptr->trans_values.blue = png_ptr->trans_values.gray; |
|
826 } |
|
827 break; |
|
828 |
|
829 case 8: |
|
830 |
|
831 case 16: |
|
832 png_ptr->background.red = png_ptr->background.green |
|
833 = png_ptr->background.blue = png_ptr->background.gray; |
|
834 break; |
|
835 } |
|
836 } |
|
837 else if (color_type == PNG_COLOR_TYPE_PALETTE) |
|
838 { |
|
839 png_ptr->background.red = |
|
840 png_ptr->palette[png_ptr->background.index].red; |
|
841 png_ptr->background.green = |
|
842 png_ptr->palette[png_ptr->background.index].green; |
|
843 png_ptr->background.blue = |
|
844 png_ptr->palette[png_ptr->background.index].blue; |
|
845 |
|
846 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
|
847 if (png_ptr->transformations & PNG_INVERT_ALPHA) |
|
848 { |
|
849 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
850 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
851 #endif |
|
852 { |
|
853 /* Invert the alpha channel (in tRNS) unless the pixels are |
|
854 * going to be expanded, in which case leave it for later |
|
855 */ |
|
856 int i, istop; |
|
857 istop=(int)png_ptr->num_trans; |
|
858 for (i=0; i<istop; i++) |
|
859 png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]); |
|
860 } |
|
861 } |
|
862 #endif |
|
863 |
|
864 } |
|
865 } |
|
866 #endif |
|
867 |
|
868 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) |
|
869 png_ptr->background_1 = png_ptr->background; |
|
870 #endif |
|
871 #if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED) |
|
872 |
|
873 if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0) |
|
874 && (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0) |
|
875 < PNG_GAMMA_THRESHOLD)) |
|
876 { |
|
877 int i, k; |
|
878 k=0; |
|
879 for (i=0; i<png_ptr->num_trans; i++) |
|
880 { |
|
881 if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff) |
|
882 k=1; /* Partial transparency is present */ |
|
883 } |
|
884 if (k == 0) |
|
885 png_ptr->transformations &= ~PNG_GAMMA; |
|
886 } |
|
887 |
|
888 if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) && |
|
889 png_ptr->gamma != 0.0) |
|
890 { |
|
891 png_build_gamma_table(png_ptr); |
|
892 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
893 if (png_ptr->transformations & PNG_BACKGROUND) |
|
894 { |
|
895 if (color_type == PNG_COLOR_TYPE_PALETTE) |
|
896 { |
|
897 /* Could skip if no transparency */ |
|
898 png_color back, back_1; |
|
899 png_colorp palette = png_ptr->palette; |
|
900 int num_palette = png_ptr->num_palette; |
|
901 int i; |
|
902 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
|
903 { |
|
904 back.red = png_ptr->gamma_table[png_ptr->background.red]; |
|
905 back.green = png_ptr->gamma_table[png_ptr->background.green]; |
|
906 back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
|
907 |
|
908 back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
|
909 back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
|
910 back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
|
911 } |
|
912 else |
|
913 { |
|
914 double g, gs; |
|
915 |
|
916 switch (png_ptr->background_gamma_type) |
|
917 { |
|
918 case PNG_BACKGROUND_GAMMA_SCREEN: |
|
919 g = (png_ptr->screen_gamma); |
|
920 gs = 1.0; |
|
921 break; |
|
922 |
|
923 case PNG_BACKGROUND_GAMMA_FILE: |
|
924 g = 1.0 / (png_ptr->gamma); |
|
925 gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
|
926 break; |
|
927 |
|
928 case PNG_BACKGROUND_GAMMA_UNIQUE: |
|
929 g = 1.0 / (png_ptr->background_gamma); |
|
930 gs = 1.0 / (png_ptr->background_gamma * |
|
931 png_ptr->screen_gamma); |
|
932 break; |
|
933 default: |
|
934 g = 1.0; /* back_1 */ |
|
935 gs = 1.0; /* back */ |
|
936 } |
|
937 |
|
938 if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD) |
|
939 { |
|
940 back.red = (png_byte)png_ptr->background.red; |
|
941 back.green = (png_byte)png_ptr->background.green; |
|
942 back.blue = (png_byte)png_ptr->background.blue; |
|
943 } |
|
944 else |
|
945 { |
|
946 back.red = (png_byte)(pow( |
|
947 (double)png_ptr->background.red/255, gs) * 255.0 + .5); |
|
948 back.green = (png_byte)(pow( |
|
949 (double)png_ptr->background.green/255, gs) * 255.0 + .5); |
|
950 back.blue = (png_byte)(pow( |
|
951 (double)png_ptr->background.blue/255, gs) * 255.0 + .5); |
|
952 } |
|
953 |
|
954 back_1.red = (png_byte)(pow( |
|
955 (double)png_ptr->background.red/255, g) * 255.0 + .5); |
|
956 back_1.green = (png_byte)(pow( |
|
957 (double)png_ptr->background.green/255, g) * 255.0 + .5); |
|
958 back_1.blue = (png_byte)(pow( |
|
959 (double)png_ptr->background.blue/255, g) * 255.0 + .5); |
|
960 } |
|
961 for (i = 0; i < num_palette; i++) |
|
962 { |
|
963 if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff) |
|
964 { |
|
965 if (png_ptr->trans[i] == 0) |
|
966 { |
|
967 palette[i] = back; |
|
968 } |
|
969 else /* if (png_ptr->trans[i] != 0xff) */ |
|
970 { |
|
971 png_byte v, w; |
|
972 |
|
973 v = png_ptr->gamma_to_1[palette[i].red]; |
|
974 png_composite(w, v, png_ptr->trans[i], back_1.red); |
|
975 palette[i].red = png_ptr->gamma_from_1[w]; |
|
976 |
|
977 v = png_ptr->gamma_to_1[palette[i].green]; |
|
978 png_composite(w, v, png_ptr->trans[i], back_1.green); |
|
979 palette[i].green = png_ptr->gamma_from_1[w]; |
|
980 |
|
981 v = png_ptr->gamma_to_1[palette[i].blue]; |
|
982 png_composite(w, v, png_ptr->trans[i], back_1.blue); |
|
983 palette[i].blue = png_ptr->gamma_from_1[w]; |
|
984 } |
|
985 } |
|
986 else |
|
987 { |
|
988 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
989 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
990 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
991 } |
|
992 } |
|
993 /* Prevent the transformations being done again, and make sure |
|
994 * that the now spurious alpha channel is stripped - the code |
|
995 * has just reduced background composition and gamma correction |
|
996 * to a simple alpha channel strip. |
|
997 */ |
|
998 png_ptr->transformations &= ~PNG_BACKGROUND; |
|
999 png_ptr->transformations &= ~PNG_GAMMA; |
|
1000 png_ptr->transformations |= PNG_STRIP_ALPHA; |
|
1001 } |
|
1002 /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ |
|
1003 else |
|
1004 /* color_type != PNG_COLOR_TYPE_PALETTE */ |
|
1005 { |
|
1006 double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1); |
|
1007 double g = 1.0; |
|
1008 double gs = 1.0; |
|
1009 |
|
1010 switch (png_ptr->background_gamma_type) |
|
1011 { |
|
1012 case PNG_BACKGROUND_GAMMA_SCREEN: |
|
1013 g = (png_ptr->screen_gamma); |
|
1014 gs = 1.0; |
|
1015 break; |
|
1016 |
|
1017 case PNG_BACKGROUND_GAMMA_FILE: |
|
1018 g = 1.0 / (png_ptr->gamma); |
|
1019 gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
|
1020 break; |
|
1021 |
|
1022 case PNG_BACKGROUND_GAMMA_UNIQUE: |
|
1023 g = 1.0 / (png_ptr->background_gamma); |
|
1024 gs = 1.0 / (png_ptr->background_gamma * |
|
1025 png_ptr->screen_gamma); |
|
1026 break; |
|
1027 } |
|
1028 |
|
1029 png_ptr->background_1.gray = (png_uint_16)(pow( |
|
1030 (double)png_ptr->background.gray / m, g) * m + .5); |
|
1031 png_ptr->background.gray = (png_uint_16)(pow( |
|
1032 (double)png_ptr->background.gray / m, gs) * m + .5); |
|
1033 |
|
1034 if ((png_ptr->background.red != png_ptr->background.green) || |
|
1035 (png_ptr->background.red != png_ptr->background.blue) || |
|
1036 (png_ptr->background.red != png_ptr->background.gray)) |
|
1037 { |
|
1038 /* RGB or RGBA with color background */ |
|
1039 png_ptr->background_1.red = (png_uint_16)(pow( |
|
1040 (double)png_ptr->background.red / m, g) * m + .5); |
|
1041 png_ptr->background_1.green = (png_uint_16)(pow( |
|
1042 (double)png_ptr->background.green / m, g) * m + .5); |
|
1043 png_ptr->background_1.blue = (png_uint_16)(pow( |
|
1044 (double)png_ptr->background.blue / m, g) * m + .5); |
|
1045 png_ptr->background.red = (png_uint_16)(pow( |
|
1046 (double)png_ptr->background.red / m, gs) * m + .5); |
|
1047 png_ptr->background.green = (png_uint_16)(pow( |
|
1048 (double)png_ptr->background.green / m, gs) * m + .5); |
|
1049 png_ptr->background.blue = (png_uint_16)(pow( |
|
1050 (double)png_ptr->background.blue / m, gs) * m + .5); |
|
1051 } |
|
1052 else |
|
1053 { |
|
1054 /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ |
|
1055 png_ptr->background_1.red = png_ptr->background_1.green |
|
1056 = png_ptr->background_1.blue = png_ptr->background_1.gray; |
|
1057 png_ptr->background.red = png_ptr->background.green |
|
1058 = png_ptr->background.blue = png_ptr->background.gray; |
|
1059 } |
|
1060 } |
|
1061 } |
|
1062 else |
|
1063 /* Transformation does not include PNG_BACKGROUND */ |
|
1064 #endif /* PNG_READ_BACKGROUND_SUPPORTED */ |
|
1065 if (color_type == PNG_COLOR_TYPE_PALETTE) |
|
1066 { |
|
1067 png_colorp palette = png_ptr->palette; |
|
1068 int num_palette = png_ptr->num_palette; |
|
1069 int i; |
|
1070 |
|
1071 for (i = 0; i < num_palette; i++) |
|
1072 { |
|
1073 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
1074 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
1075 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
1076 } |
|
1077 |
|
1078 /* Done the gamma correction. */ |
|
1079 png_ptr->transformations &= ~PNG_GAMMA; |
|
1080 } |
|
1081 } |
|
1082 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1083 else |
|
1084 #endif |
|
1085 #endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */ |
|
1086 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1087 /* No GAMMA transformation */ |
|
1088 if ((png_ptr->transformations & PNG_BACKGROUND) && |
|
1089 (color_type == PNG_COLOR_TYPE_PALETTE)) |
|
1090 { |
|
1091 int i; |
|
1092 int istop = (int)png_ptr->num_trans; |
|
1093 png_color back; |
|
1094 png_colorp palette = png_ptr->palette; |
|
1095 |
|
1096 back.red = (png_byte)png_ptr->background.red; |
|
1097 back.green = (png_byte)png_ptr->background.green; |
|
1098 back.blue = (png_byte)png_ptr->background.blue; |
|
1099 |
|
1100 for (i = 0; i < istop; i++) |
|
1101 { |
|
1102 if (png_ptr->trans[i] == 0) |
|
1103 { |
|
1104 palette[i] = back; |
|
1105 } |
|
1106 else if (png_ptr->trans[i] != 0xff) |
|
1107 { |
|
1108 /* The png_composite() macro is defined in png.h */ |
|
1109 png_composite(palette[i].red, palette[i].red, |
|
1110 png_ptr->trans[i], back.red); |
|
1111 png_composite(palette[i].green, palette[i].green, |
|
1112 png_ptr->trans[i], back.green); |
|
1113 png_composite(palette[i].blue, palette[i].blue, |
|
1114 png_ptr->trans[i], back.blue); |
|
1115 } |
|
1116 } |
|
1117 |
|
1118 /* Handled alpha, still need to strip the channel. */ |
|
1119 png_ptr->transformations &= ~PNG_BACKGROUND; |
|
1120 png_ptr->transformations |= PNG_STRIP_ALPHA; |
|
1121 } |
|
1122 #endif /* PNG_READ_BACKGROUND_SUPPORTED */ |
|
1123 |
|
1124 #if defined(PNG_READ_SHIFT_SUPPORTED) |
|
1125 if ((png_ptr->transformations & PNG_SHIFT) && |
|
1126 (color_type == PNG_COLOR_TYPE_PALETTE)) |
|
1127 { |
|
1128 png_uint_16 i; |
|
1129 png_uint_16 istop = png_ptr->num_palette; |
|
1130 int sr = 8 - png_ptr->sig_bit.red; |
|
1131 int sg = 8 - png_ptr->sig_bit.green; |
|
1132 int sb = 8 - png_ptr->sig_bit.blue; |
|
1133 |
|
1134 if (sr < 0 || sr > 8) |
|
1135 sr = 0; |
|
1136 if (sg < 0 || sg > 8) |
|
1137 sg = 0; |
|
1138 if (sb < 0 || sb > 8) |
|
1139 sb = 0; |
|
1140 for (i = 0; i < istop; i++) |
|
1141 { |
|
1142 png_ptr->palette[i].red >>= sr; |
|
1143 png_ptr->palette[i].green >>= sg; |
|
1144 png_ptr->palette[i].blue >>= sb; |
|
1145 } |
|
1146 } |
|
1147 #endif /* PNG_READ_SHIFT_SUPPORTED */ |
|
1148 } |
|
1149 #if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \ |
|
1150 && !defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1151 if (png_ptr) |
|
1152 return; |
|
1153 #endif |
|
1154 } |
|
1155 |
|
1156 /* Modify the info structure to reflect the transformations. The |
|
1157 * info should be updated so a PNG file could be written with it, |
|
1158 * assuming the transformations result in valid PNG data. |
|
1159 */ |
|
1160 void /* PRIVATE */ |
|
1161 png_read_transform_info(png_structp png_ptr, png_infop info_ptr) |
|
1162 { |
|
1163 png_debug(1, "in png_read_transform_info"); |
|
1164 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
1165 if (png_ptr->transformations & PNG_EXPAND) |
|
1166 { |
|
1167 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
1168 { |
|
1169 if (png_ptr->num_trans && |
|
1170 (png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
1171 info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
|
1172 else |
|
1173 info_ptr->color_type = PNG_COLOR_TYPE_RGB; |
|
1174 info_ptr->bit_depth = 8; |
|
1175 info_ptr->num_trans = 0; |
|
1176 } |
|
1177 else |
|
1178 { |
|
1179 if (png_ptr->num_trans) |
|
1180 { |
|
1181 if (png_ptr->transformations & PNG_EXPAND_tRNS) |
|
1182 info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
|
1183 } |
|
1184 if (info_ptr->bit_depth < 8) |
|
1185 info_ptr->bit_depth = 8; |
|
1186 info_ptr->num_trans = 0; |
|
1187 } |
|
1188 } |
|
1189 #endif |
|
1190 |
|
1191 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1192 if (png_ptr->transformations & PNG_BACKGROUND) |
|
1193 { |
|
1194 info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; |
|
1195 info_ptr->num_trans = 0; |
|
1196 info_ptr->background = png_ptr->background; |
|
1197 } |
|
1198 #endif |
|
1199 |
|
1200 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
1201 if (png_ptr->transformations & PNG_GAMMA) |
|
1202 { |
|
1203 #ifdef PNG_FLOATING_POINT_SUPPORTED |
|
1204 info_ptr->gamma = png_ptr->gamma; |
|
1205 #endif |
|
1206 #ifdef PNG_FIXED_POINT_SUPPORTED |
|
1207 info_ptr->int_gamma = png_ptr->int_gamma; |
|
1208 #endif |
|
1209 } |
|
1210 #endif |
|
1211 |
|
1212 #if defined(PNG_READ_16_TO_8_SUPPORTED) |
|
1213 if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16)) |
|
1214 info_ptr->bit_depth = 8; |
|
1215 #endif |
|
1216 |
|
1217 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
1218 if (png_ptr->transformations & PNG_GRAY_TO_RGB) |
|
1219 info_ptr->color_type |= PNG_COLOR_MASK_COLOR; |
|
1220 #endif |
|
1221 |
|
1222 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
1223 if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
|
1224 info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR; |
|
1225 #endif |
|
1226 |
|
1227 #if defined(PNG_READ_DITHER_SUPPORTED) |
|
1228 if (png_ptr->transformations & PNG_DITHER) |
|
1229 { |
|
1230 if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || |
|
1231 (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && |
|
1232 png_ptr->palette_lookup && info_ptr->bit_depth == 8) |
|
1233 { |
|
1234 info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; |
|
1235 } |
|
1236 } |
|
1237 #endif |
|
1238 |
|
1239 #if defined(PNG_READ_PACK_SUPPORTED) |
|
1240 if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8)) |
|
1241 info_ptr->bit_depth = 8; |
|
1242 #endif |
|
1243 |
|
1244 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
1245 info_ptr->channels = 1; |
|
1246 else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) |
|
1247 info_ptr->channels = 3; |
|
1248 else |
|
1249 info_ptr->channels = 1; |
|
1250 |
|
1251 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
|
1252 if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) |
|
1253 info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; |
|
1254 #endif |
|
1255 |
|
1256 if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) |
|
1257 info_ptr->channels++; |
|
1258 |
|
1259 #if defined(PNG_READ_FILLER_SUPPORTED) |
|
1260 /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ |
|
1261 if ((png_ptr->transformations & PNG_FILLER) && |
|
1262 ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || |
|
1263 (info_ptr->color_type == PNG_COLOR_TYPE_GRAY))) |
|
1264 { |
|
1265 info_ptr->channels++; |
|
1266 /* If adding a true alpha channel not just filler */ |
|
1267 #if !defined(PNG_1_0_X) |
|
1268 if (png_ptr->transformations & PNG_ADD_ALPHA) |
|
1269 info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
|
1270 #endif |
|
1271 } |
|
1272 #endif |
|
1273 |
|
1274 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \ |
|
1275 defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
|
1276 if (png_ptr->transformations & PNG_USER_TRANSFORM) |
|
1277 { |
|
1278 if (info_ptr->bit_depth < png_ptr->user_transform_depth) |
|
1279 info_ptr->bit_depth = png_ptr->user_transform_depth; |
|
1280 if (info_ptr->channels < png_ptr->user_transform_channels) |
|
1281 info_ptr->channels = png_ptr->user_transform_channels; |
|
1282 } |
|
1283 #endif |
|
1284 |
|
1285 info_ptr->pixel_depth = (png_byte)(info_ptr->channels * |
|
1286 info_ptr->bit_depth); |
|
1287 |
|
1288 info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width); |
|
1289 |
|
1290 #if !defined(PNG_READ_EXPAND_SUPPORTED) |
|
1291 if (png_ptr) |
|
1292 return; |
|
1293 #endif |
|
1294 } |
|
1295 |
|
1296 /* Transform the row. The order of transformations is significant, |
|
1297 * and is very touchy. If you add a transformation, take care to |
|
1298 * decide how it fits in with the other transformations here. |
|
1299 */ |
|
1300 void /* PRIVATE */ |
|
1301 png_do_read_transformations(png_structp png_ptr) |
|
1302 { |
|
1303 png_debug(1, "in png_do_read_transformations"); |
|
1304 if (png_ptr->row_buf == NULL) |
|
1305 { |
|
1306 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE) |
|
1307 char msg[50]; |
|
1308 |
|
1309 png_snprintf2(msg, 50, |
|
1310 "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number, |
|
1311 png_ptr->pass); |
|
1312 png_error(png_ptr, msg); |
|
1313 #else |
|
1314 png_error(png_ptr, "NULL row buffer"); |
|
1315 #endif |
|
1316 } |
|
1317 #ifdef PNG_WARN_UNINITIALIZED_ROW |
|
1318 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) |
|
1319 /* Application has failed to call either png_read_start_image() |
|
1320 * or png_read_update_info() after setting transforms that expand |
|
1321 * pixels. This check added to libpng-1.2.19 |
|
1322 */ |
|
1323 #if (PNG_WARN_UNINITIALIZED_ROW==1) |
|
1324 png_error(png_ptr, "Uninitialized row"); |
|
1325 #else |
|
1326 png_warning(png_ptr, "Uninitialized row"); |
|
1327 #endif |
|
1328 #endif |
|
1329 |
|
1330 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
1331 if (png_ptr->transformations & PNG_EXPAND) |
|
1332 { |
|
1333 if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE) |
|
1334 { |
|
1335 png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1336 png_ptr->palette, png_ptr->trans, png_ptr->num_trans); |
|
1337 } |
|
1338 else |
|
1339 { |
|
1340 if (png_ptr->num_trans && |
|
1341 (png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
1342 png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1343 &(png_ptr->trans_values)); |
|
1344 else |
|
1345 png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1346 NULL); |
|
1347 } |
|
1348 } |
|
1349 #endif |
|
1350 |
|
1351 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
|
1352 if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) |
|
1353 png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1354 PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)); |
|
1355 #endif |
|
1356 |
|
1357 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
1358 if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
|
1359 { |
|
1360 int rgb_error = |
|
1361 png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1362 if (rgb_error) |
|
1363 { |
|
1364 png_ptr->rgb_to_gray_status=1; |
|
1365 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == |
|
1366 PNG_RGB_TO_GRAY_WARN) |
|
1367 png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
|
1368 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == |
|
1369 PNG_RGB_TO_GRAY_ERR) |
|
1370 png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
|
1371 } |
|
1372 } |
|
1373 #endif |
|
1374 |
|
1375 /* From Andreas Dilger e-mail to png-implement, 26 March 1998: |
|
1376 * |
|
1377 * In most cases, the "simple transparency" should be done prior to doing |
|
1378 * gray-to-RGB, or you will have to test 3x as many bytes to check if a |
|
1379 * pixel is transparent. You would also need to make sure that the |
|
1380 * transparency information is upgraded to RGB. |
|
1381 * |
|
1382 * To summarize, the current flow is: |
|
1383 * - Gray + simple transparency -> compare 1 or 2 gray bytes and composite |
|
1384 * with background "in place" if transparent, |
|
1385 * convert to RGB if necessary |
|
1386 * - Gray + alpha -> composite with gray background and remove alpha bytes, |
|
1387 * convert to RGB if necessary |
|
1388 * |
|
1389 * To support RGB backgrounds for gray images we need: |
|
1390 * - Gray + simple transparency -> convert to RGB + simple transparency, |
|
1391 * compare 3 or 6 bytes and composite with |
|
1392 * background "in place" if transparent |
|
1393 * (3x compare/pixel compared to doing |
|
1394 * composite with gray bkgrnd) |
|
1395 * - Gray + alpha -> convert to RGB + alpha, composite with background and |
|
1396 * remove alpha bytes (3x float |
|
1397 * operations/pixel compared with composite |
|
1398 * on gray background) |
|
1399 * |
|
1400 * Greg's change will do this. The reason it wasn't done before is for |
|
1401 * performance, as this increases the per-pixel operations. If we would check |
|
1402 * in advance if the background was gray or RGB, and position the gray-to-RGB |
|
1403 * transform appropriately, then it would save a lot of work/time. |
|
1404 */ |
|
1405 |
|
1406 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
1407 /* If gray -> RGB, do so now only if background is non-gray; else do later |
|
1408 * for performance reasons |
|
1409 */ |
|
1410 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && |
|
1411 !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) |
|
1412 png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1413 #endif |
|
1414 |
|
1415 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1416 if ((png_ptr->transformations & PNG_BACKGROUND) && |
|
1417 ((png_ptr->num_trans != 0 ) || |
|
1418 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) |
|
1419 png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1420 &(png_ptr->trans_values), &(png_ptr->background) |
|
1421 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
1422 , &(png_ptr->background_1), |
|
1423 png_ptr->gamma_table, png_ptr->gamma_from_1, |
|
1424 png_ptr->gamma_to_1, png_ptr->gamma_16_table, |
|
1425 png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1, |
|
1426 png_ptr->gamma_shift |
|
1427 #endif |
|
1428 ); |
|
1429 #endif |
|
1430 |
|
1431 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
1432 if ((png_ptr->transformations & PNG_GAMMA) && |
|
1433 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1434 !((png_ptr->transformations & PNG_BACKGROUND) && |
|
1435 ((png_ptr->num_trans != 0) || |
|
1436 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) && |
|
1437 #endif |
|
1438 (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) |
|
1439 png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1440 png_ptr->gamma_table, png_ptr->gamma_16_table, |
|
1441 png_ptr->gamma_shift); |
|
1442 #endif |
|
1443 |
|
1444 #if defined(PNG_READ_16_TO_8_SUPPORTED) |
|
1445 if (png_ptr->transformations & PNG_16_TO_8) |
|
1446 png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1447 #endif |
|
1448 |
|
1449 #if defined(PNG_READ_DITHER_SUPPORTED) |
|
1450 if (png_ptr->transformations & PNG_DITHER) |
|
1451 { |
|
1452 png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1453 png_ptr->palette_lookup, png_ptr->dither_index); |
|
1454 if (png_ptr->row_info.rowbytes == (png_uint_32)0) |
|
1455 png_error(png_ptr, "png_do_dither returned rowbytes=0"); |
|
1456 } |
|
1457 #endif |
|
1458 |
|
1459 #if defined(PNG_READ_INVERT_SUPPORTED) |
|
1460 if (png_ptr->transformations & PNG_INVERT_MONO) |
|
1461 png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1462 #endif |
|
1463 |
|
1464 #if defined(PNG_READ_SHIFT_SUPPORTED) |
|
1465 if (png_ptr->transformations & PNG_SHIFT) |
|
1466 png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1467 &(png_ptr->shift)); |
|
1468 #endif |
|
1469 |
|
1470 #if defined(PNG_READ_PACK_SUPPORTED) |
|
1471 if (png_ptr->transformations & PNG_PACK) |
|
1472 png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1473 #endif |
|
1474 |
|
1475 #if defined(PNG_READ_BGR_SUPPORTED) |
|
1476 if (png_ptr->transformations & PNG_BGR) |
|
1477 png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1478 #endif |
|
1479 |
|
1480 #if defined(PNG_READ_PACKSWAP_SUPPORTED) |
|
1481 if (png_ptr->transformations & PNG_PACKSWAP) |
|
1482 png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1483 #endif |
|
1484 |
|
1485 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
1486 /* If gray -> RGB, do so now only if we did not do so above */ |
|
1487 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && |
|
1488 (png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) |
|
1489 png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1490 #endif |
|
1491 |
|
1492 #if defined(PNG_READ_FILLER_SUPPORTED) |
|
1493 if (png_ptr->transformations & PNG_FILLER) |
|
1494 png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1495 (png_uint_32)png_ptr->filler, png_ptr->flags); |
|
1496 #endif |
|
1497 |
|
1498 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
|
1499 if (png_ptr->transformations & PNG_INVERT_ALPHA) |
|
1500 png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1501 #endif |
|
1502 |
|
1503 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) |
|
1504 if (png_ptr->transformations & PNG_SWAP_ALPHA) |
|
1505 png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1506 #endif |
|
1507 |
|
1508 #if defined(PNG_READ_SWAP_SUPPORTED) |
|
1509 if (png_ptr->transformations & PNG_SWAP_BYTES) |
|
1510 png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1511 #endif |
|
1512 |
|
1513 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
|
1514 if (png_ptr->transformations & PNG_USER_TRANSFORM) |
|
1515 { |
|
1516 if (png_ptr->read_user_transform_fn != NULL) |
|
1517 (*(png_ptr->read_user_transform_fn)) /* User read transform function */ |
|
1518 (png_ptr, /* png_ptr */ |
|
1519 &(png_ptr->row_info), /* row_info: */ |
|
1520 /* png_uint_32 width; width of row */ |
|
1521 /* png_uint_32 rowbytes; number of bytes in row */ |
|
1522 /* png_byte color_type; color type of pixels */ |
|
1523 /* png_byte bit_depth; bit depth of samples */ |
|
1524 /* png_byte channels; number of channels (1-4) */ |
|
1525 /* png_byte pixel_depth; bits per pixel (depth*channels) */ |
|
1526 png_ptr->row_buf + 1); /* start of pixel data for row */ |
|
1527 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) |
|
1528 if (png_ptr->user_transform_depth) |
|
1529 png_ptr->row_info.bit_depth = png_ptr->user_transform_depth; |
|
1530 if (png_ptr->user_transform_channels) |
|
1531 png_ptr->row_info.channels = png_ptr->user_transform_channels; |
|
1532 #endif |
|
1533 png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * |
|
1534 png_ptr->row_info.channels); |
|
1535 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, |
|
1536 png_ptr->row_info.width); |
|
1537 } |
|
1538 #endif |
|
1539 |
|
1540 } |
|
1541 |
|
1542 #if defined(PNG_READ_PACK_SUPPORTED) |
|
1543 /* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, |
|
1544 * without changing the actual values. Thus, if you had a row with |
|
1545 * a bit depth of 1, you would end up with bytes that only contained |
|
1546 * the numbers 0 or 1. If you would rather they contain 0 and 255, use |
|
1547 * png_do_shift() after this. |
|
1548 */ |
|
1549 void /* PRIVATE */ |
|
1550 png_do_unpack(png_row_infop row_info, png_bytep row) |
|
1551 { |
|
1552 png_debug(1, "in png_do_unpack"); |
|
1553 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
1554 if (row != NULL && row_info != NULL && row_info->bit_depth < 8) |
|
1555 #else |
|
1556 if (row_info->bit_depth < 8) |
|
1557 #endif |
|
1558 { |
|
1559 png_uint_32 i; |
|
1560 png_uint_32 row_width=row_info->width; |
|
1561 |
|
1562 switch (row_info->bit_depth) |
|
1563 { |
|
1564 case 1: |
|
1565 { |
|
1566 png_bytep sp = row + (png_size_t)((row_width - 1) >> 3); |
|
1567 png_bytep dp = row + (png_size_t)row_width - 1; |
|
1568 png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07); |
|
1569 for (i = 0; i < row_width; i++) |
|
1570 { |
|
1571 *dp = (png_byte)((*sp >> shift) & 0x01); |
|
1572 if (shift == 7) |
|
1573 { |
|
1574 shift = 0; |
|
1575 sp--; |
|
1576 } |
|
1577 else |
|
1578 shift++; |
|
1579 |
|
1580 dp--; |
|
1581 } |
|
1582 break; |
|
1583 } |
|
1584 |
|
1585 case 2: |
|
1586 { |
|
1587 |
|
1588 png_bytep sp = row + (png_size_t)((row_width - 1) >> 2); |
|
1589 png_bytep dp = row + (png_size_t)row_width - 1; |
|
1590 png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
|
1591 for (i = 0; i < row_width; i++) |
|
1592 { |
|
1593 *dp = (png_byte)((*sp >> shift) & 0x03); |
|
1594 if (shift == 6) |
|
1595 { |
|
1596 shift = 0; |
|
1597 sp--; |
|
1598 } |
|
1599 else |
|
1600 shift += 2; |
|
1601 |
|
1602 dp--; |
|
1603 } |
|
1604 break; |
|
1605 } |
|
1606 |
|
1607 case 4: |
|
1608 { |
|
1609 png_bytep sp = row + (png_size_t)((row_width - 1) >> 1); |
|
1610 png_bytep dp = row + (png_size_t)row_width - 1; |
|
1611 png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); |
|
1612 for (i = 0; i < row_width; i++) |
|
1613 { |
|
1614 *dp = (png_byte)((*sp >> shift) & 0x0f); |
|
1615 if (shift == 4) |
|
1616 { |
|
1617 shift = 0; |
|
1618 sp--; |
|
1619 } |
|
1620 else |
|
1621 shift = 4; |
|
1622 |
|
1623 dp--; |
|
1624 } |
|
1625 break; |
|
1626 } |
|
1627 } |
|
1628 row_info->bit_depth = 8; |
|
1629 row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
|
1630 row_info->rowbytes = row_width * row_info->channels; |
|
1631 } |
|
1632 } |
|
1633 #endif |
|
1634 |
|
1635 #if defined(PNG_READ_SHIFT_SUPPORTED) |
|
1636 /* Reverse the effects of png_do_shift. This routine merely shifts the |
|
1637 * pixels back to their significant bits values. Thus, if you have |
|
1638 * a row of bit depth 8, but only 5 are significant, this will shift |
|
1639 * the values back to 0 through 31. |
|
1640 */ |
|
1641 void /* PRIVATE */ |
|
1642 png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits) |
|
1643 { |
|
1644 png_debug(1, "in png_do_unshift"); |
|
1645 if ( |
|
1646 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
1647 row != NULL && row_info != NULL && sig_bits != NULL && |
|
1648 #endif |
|
1649 row_info->color_type != PNG_COLOR_TYPE_PALETTE) |
|
1650 { |
|
1651 int shift[4]; |
|
1652 int channels = 0; |
|
1653 int c; |
|
1654 png_uint_16 value = 0; |
|
1655 png_uint_32 row_width = row_info->width; |
|
1656 |
|
1657 if (row_info->color_type & PNG_COLOR_MASK_COLOR) |
|
1658 { |
|
1659 shift[channels++] = row_info->bit_depth - sig_bits->red; |
|
1660 shift[channels++] = row_info->bit_depth - sig_bits->green; |
|
1661 shift[channels++] = row_info->bit_depth - sig_bits->blue; |
|
1662 } |
|
1663 else |
|
1664 { |
|
1665 shift[channels++] = row_info->bit_depth - sig_bits->gray; |
|
1666 } |
|
1667 if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
|
1668 { |
|
1669 shift[channels++] = row_info->bit_depth - sig_bits->alpha; |
|
1670 } |
|
1671 |
|
1672 for (c = 0; c < channels; c++) |
|
1673 { |
|
1674 if (shift[c] <= 0) |
|
1675 shift[c] = 0; |
|
1676 else |
|
1677 value = 1; |
|
1678 } |
|
1679 |
|
1680 if (!value) |
|
1681 return; |
|
1682 |
|
1683 switch (row_info->bit_depth) |
|
1684 { |
|
1685 case 2: |
|
1686 { |
|
1687 png_bytep bp; |
|
1688 png_uint_32 i; |
|
1689 png_uint_32 istop = row_info->rowbytes; |
|
1690 |
|
1691 for (bp = row, i = 0; i < istop; i++) |
|
1692 { |
|
1693 *bp >>= 1; |
|
1694 *bp++ &= 0x55; |
|
1695 } |
|
1696 break; |
|
1697 } |
|
1698 |
|
1699 case 4: |
|
1700 { |
|
1701 png_bytep bp = row; |
|
1702 png_uint_32 i; |
|
1703 png_uint_32 istop = row_info->rowbytes; |
|
1704 png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) | |
|
1705 (png_byte)((int)0xf >> shift[0])); |
|
1706 |
|
1707 for (i = 0; i < istop; i++) |
|
1708 { |
|
1709 *bp >>= shift[0]; |
|
1710 *bp++ &= mask; |
|
1711 } |
|
1712 break; |
|
1713 } |
|
1714 |
|
1715 case 8: |
|
1716 { |
|
1717 png_bytep bp = row; |
|
1718 png_uint_32 i; |
|
1719 png_uint_32 istop = row_width * channels; |
|
1720 |
|
1721 for (i = 0; i < istop; i++) |
|
1722 { |
|
1723 *bp++ >>= shift[i%channels]; |
|
1724 } |
|
1725 break; |
|
1726 } |
|
1727 |
|
1728 case 16: |
|
1729 { |
|
1730 png_bytep bp = row; |
|
1731 png_uint_32 i; |
|
1732 png_uint_32 istop = channels * row_width; |
|
1733 |
|
1734 for (i = 0; i < istop; i++) |
|
1735 { |
|
1736 value = (png_uint_16)((*bp << 8) + *(bp + 1)); |
|
1737 value >>= shift[i%channels]; |
|
1738 *bp++ = (png_byte)(value >> 8); |
|
1739 *bp++ = (png_byte)(value & 0xff); |
|
1740 } |
|
1741 break; |
|
1742 } |
|
1743 } |
|
1744 } |
|
1745 } |
|
1746 #endif |
|
1747 |
|
1748 #if defined(PNG_READ_16_TO_8_SUPPORTED) |
|
1749 /* Chop rows of bit depth 16 down to 8 */ |
|
1750 void /* PRIVATE */ |
|
1751 png_do_chop(png_row_infop row_info, png_bytep row) |
|
1752 { |
|
1753 png_debug(1, "in png_do_chop"); |
|
1754 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
1755 if (row != NULL && row_info != NULL && row_info->bit_depth == 16) |
|
1756 #else |
|
1757 if (row_info->bit_depth == 16) |
|
1758 #endif |
|
1759 { |
|
1760 png_bytep sp = row; |
|
1761 png_bytep dp = row; |
|
1762 png_uint_32 i; |
|
1763 png_uint_32 istop = row_info->width * row_info->channels; |
|
1764 |
|
1765 for (i = 0; i<istop; i++, sp += 2, dp++) |
|
1766 { |
|
1767 #if defined(PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED) |
|
1768 /* This does a more accurate scaling of the 16-bit color |
|
1769 * value, rather than a simple low-byte truncation. |
|
1770 * |
|
1771 * What the ideal calculation should be: |
|
1772 * *dp = (((((png_uint_32)(*sp) << 8) | |
|
1773 * (png_uint_32)(*(sp + 1))) * 255 + 127) |
|
1774 * / (png_uint_32)65535L; |
|
1775 * |
|
1776 * GRR: no, I think this is what it really should be: |
|
1777 * *dp = (((((png_uint_32)(*sp) << 8) | |
|
1778 * (png_uint_32)(*(sp + 1))) + 128L) |
|
1779 * / (png_uint_32)257L; |
|
1780 * |
|
1781 * GRR: here's the exact calculation with shifts: |
|
1782 * temp = (((png_uint_32)(*sp) << 8) | |
|
1783 * (png_uint_32)(*(sp + 1))) + 128L; |
|
1784 * *dp = (temp - (temp >> 8)) >> 8; |
|
1785 * |
|
1786 * Approximate calculation with shift/add instead of multiply/divide: |
|
1787 * *dp = ((((png_uint_32)(*sp) << 8) | |
|
1788 * (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8; |
|
1789 * |
|
1790 * What we actually do to avoid extra shifting and conversion: |
|
1791 */ |
|
1792 |
|
1793 *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0); |
|
1794 #else |
|
1795 /* Simply discard the low order byte */ |
|
1796 *dp = *sp; |
|
1797 #endif |
|
1798 } |
|
1799 row_info->bit_depth = 8; |
|
1800 row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
|
1801 row_info->rowbytes = row_info->width * row_info->channels; |
|
1802 } |
|
1803 } |
|
1804 #endif |
|
1805 |
|
1806 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) |
|
1807 void /* PRIVATE */ |
|
1808 png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) |
|
1809 { |
|
1810 png_debug(1, "in png_do_read_swap_alpha"); |
|
1811 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
1812 if (row != NULL && row_info != NULL) |
|
1813 #endif |
|
1814 { |
|
1815 png_uint_32 row_width = row_info->width; |
|
1816 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
1817 { |
|
1818 /* This converts from RGBA to ARGB */ |
|
1819 if (row_info->bit_depth == 8) |
|
1820 { |
|
1821 png_bytep sp = row + row_info->rowbytes; |
|
1822 png_bytep dp = sp; |
|
1823 png_byte save; |
|
1824 png_uint_32 i; |
|
1825 |
|
1826 for (i = 0; i < row_width; i++) |
|
1827 { |
|
1828 save = *(--sp); |
|
1829 *(--dp) = *(--sp); |
|
1830 *(--dp) = *(--sp); |
|
1831 *(--dp) = *(--sp); |
|
1832 *(--dp) = save; |
|
1833 } |
|
1834 } |
|
1835 /* This converts from RRGGBBAA to AARRGGBB */ |
|
1836 else |
|
1837 { |
|
1838 png_bytep sp = row + row_info->rowbytes; |
|
1839 png_bytep dp = sp; |
|
1840 png_byte save[2]; |
|
1841 png_uint_32 i; |
|
1842 |
|
1843 for (i = 0; i < row_width; i++) |
|
1844 { |
|
1845 save[0] = *(--sp); |
|
1846 save[1] = *(--sp); |
|
1847 *(--dp) = *(--sp); |
|
1848 *(--dp) = *(--sp); |
|
1849 *(--dp) = *(--sp); |
|
1850 *(--dp) = *(--sp); |
|
1851 *(--dp) = *(--sp); |
|
1852 *(--dp) = *(--sp); |
|
1853 *(--dp) = save[0]; |
|
1854 *(--dp) = save[1]; |
|
1855 } |
|
1856 } |
|
1857 } |
|
1858 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
1859 { |
|
1860 /* This converts from GA to AG */ |
|
1861 if (row_info->bit_depth == 8) |
|
1862 { |
|
1863 png_bytep sp = row + row_info->rowbytes; |
|
1864 png_bytep dp = sp; |
|
1865 png_byte save; |
|
1866 png_uint_32 i; |
|
1867 |
|
1868 for (i = 0; i < row_width; i++) |
|
1869 { |
|
1870 save = *(--sp); |
|
1871 *(--dp) = *(--sp); |
|
1872 *(--dp) = save; |
|
1873 } |
|
1874 } |
|
1875 /* This converts from GGAA to AAGG */ |
|
1876 else |
|
1877 { |
|
1878 png_bytep sp = row + row_info->rowbytes; |
|
1879 png_bytep dp = sp; |
|
1880 png_byte save[2]; |
|
1881 png_uint_32 i; |
|
1882 |
|
1883 for (i = 0; i < row_width; i++) |
|
1884 { |
|
1885 save[0] = *(--sp); |
|
1886 save[1] = *(--sp); |
|
1887 *(--dp) = *(--sp); |
|
1888 *(--dp) = *(--sp); |
|
1889 *(--dp) = save[0]; |
|
1890 *(--dp) = save[1]; |
|
1891 } |
|
1892 } |
|
1893 } |
|
1894 } |
|
1895 } |
|
1896 #endif |
|
1897 |
|
1898 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
|
1899 void /* PRIVATE */ |
|
1900 png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) |
|
1901 { |
|
1902 png_debug(1, "in png_do_read_invert_alpha"); |
|
1903 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
1904 if (row != NULL && row_info != NULL) |
|
1905 #endif |
|
1906 { |
|
1907 png_uint_32 row_width = row_info->width; |
|
1908 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
1909 { |
|
1910 /* This inverts the alpha channel in RGBA */ |
|
1911 if (row_info->bit_depth == 8) |
|
1912 { |
|
1913 png_bytep sp = row + row_info->rowbytes; |
|
1914 png_bytep dp = sp; |
|
1915 png_uint_32 i; |
|
1916 |
|
1917 for (i = 0; i < row_width; i++) |
|
1918 { |
|
1919 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1920 |
|
1921 /* This does nothing: |
|
1922 *(--dp) = *(--sp); |
|
1923 *(--dp) = *(--sp); |
|
1924 *(--dp) = *(--sp); |
|
1925 We can replace it with: |
|
1926 */ |
|
1927 sp-=3; |
|
1928 dp=sp; |
|
1929 } |
|
1930 } |
|
1931 /* This inverts the alpha channel in RRGGBBAA */ |
|
1932 else |
|
1933 { |
|
1934 png_bytep sp = row + row_info->rowbytes; |
|
1935 png_bytep dp = sp; |
|
1936 png_uint_32 i; |
|
1937 |
|
1938 for (i = 0; i < row_width; i++) |
|
1939 { |
|
1940 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1941 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1942 |
|
1943 /* This does nothing: |
|
1944 *(--dp) = *(--sp); |
|
1945 *(--dp) = *(--sp); |
|
1946 *(--dp) = *(--sp); |
|
1947 *(--dp) = *(--sp); |
|
1948 *(--dp) = *(--sp); |
|
1949 *(--dp) = *(--sp); |
|
1950 We can replace it with: |
|
1951 */ |
|
1952 sp-=6; |
|
1953 dp=sp; |
|
1954 } |
|
1955 } |
|
1956 } |
|
1957 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
1958 { |
|
1959 /* This inverts the alpha channel in GA */ |
|
1960 if (row_info->bit_depth == 8) |
|
1961 { |
|
1962 png_bytep sp = row + row_info->rowbytes; |
|
1963 png_bytep dp = sp; |
|
1964 png_uint_32 i; |
|
1965 |
|
1966 for (i = 0; i < row_width; i++) |
|
1967 { |
|
1968 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1969 *(--dp) = *(--sp); |
|
1970 } |
|
1971 } |
|
1972 /* This inverts the alpha channel in GGAA */ |
|
1973 else |
|
1974 { |
|
1975 png_bytep sp = row + row_info->rowbytes; |
|
1976 png_bytep dp = sp; |
|
1977 png_uint_32 i; |
|
1978 |
|
1979 for (i = 0; i < row_width; i++) |
|
1980 { |
|
1981 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1982 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1983 /* |
|
1984 *(--dp) = *(--sp); |
|
1985 *(--dp) = *(--sp); |
|
1986 */ |
|
1987 sp-=2; |
|
1988 dp=sp; |
|
1989 } |
|
1990 } |
|
1991 } |
|
1992 } |
|
1993 } |
|
1994 #endif |
|
1995 |
|
1996 #if defined(PNG_READ_FILLER_SUPPORTED) |
|
1997 /* Add filler channel if we have RGB color */ |
|
1998 void /* PRIVATE */ |
|
1999 png_do_read_filler(png_row_infop row_info, png_bytep row, |
|
2000 png_uint_32 filler, png_uint_32 flags) |
|
2001 { |
|
2002 png_uint_32 i; |
|
2003 png_uint_32 row_width = row_info->width; |
|
2004 |
|
2005 png_byte hi_filler = (png_byte)((filler>>8) & 0xff); |
|
2006 png_byte lo_filler = (png_byte)(filler & 0xff); |
|
2007 |
|
2008 png_debug(1, "in png_do_read_filler"); |
|
2009 if ( |
|
2010 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
2011 row != NULL && row_info != NULL && |
|
2012 #endif |
|
2013 row_info->color_type == PNG_COLOR_TYPE_GRAY) |
|
2014 { |
|
2015 if (row_info->bit_depth == 8) |
|
2016 { |
|
2017 /* This changes the data from G to GX */ |
|
2018 if (flags & PNG_FLAG_FILLER_AFTER) |
|
2019 { |
|
2020 png_bytep sp = row + (png_size_t)row_width; |
|
2021 png_bytep dp = sp + (png_size_t)row_width; |
|
2022 for (i = 1; i < row_width; i++) |
|
2023 { |
|
2024 *(--dp) = lo_filler; |
|
2025 *(--dp) = *(--sp); |
|
2026 } |
|
2027 *(--dp) = lo_filler; |
|
2028 row_info->channels = 2; |
|
2029 row_info->pixel_depth = 16; |
|
2030 row_info->rowbytes = row_width * 2; |
|
2031 } |
|
2032 /* This changes the data from G to XG */ |
|
2033 else |
|
2034 { |
|
2035 png_bytep sp = row + (png_size_t)row_width; |
|
2036 png_bytep dp = sp + (png_size_t)row_width; |
|
2037 for (i = 0; i < row_width; i++) |
|
2038 { |
|
2039 *(--dp) = *(--sp); |
|
2040 *(--dp) = lo_filler; |
|
2041 } |
|
2042 row_info->channels = 2; |
|
2043 row_info->pixel_depth = 16; |
|
2044 row_info->rowbytes = row_width * 2; |
|
2045 } |
|
2046 } |
|
2047 else if (row_info->bit_depth == 16) |
|
2048 { |
|
2049 /* This changes the data from GG to GGXX */ |
|
2050 if (flags & PNG_FLAG_FILLER_AFTER) |
|
2051 { |
|
2052 png_bytep sp = row + (png_size_t)row_width * 2; |
|
2053 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2054 for (i = 1; i < row_width; i++) |
|
2055 { |
|
2056 *(--dp) = hi_filler; |
|
2057 *(--dp) = lo_filler; |
|
2058 *(--dp) = *(--sp); |
|
2059 *(--dp) = *(--sp); |
|
2060 } |
|
2061 *(--dp) = hi_filler; |
|
2062 *(--dp) = lo_filler; |
|
2063 row_info->channels = 2; |
|
2064 row_info->pixel_depth = 32; |
|
2065 row_info->rowbytes = row_width * 4; |
|
2066 } |
|
2067 /* This changes the data from GG to XXGG */ |
|
2068 else |
|
2069 { |
|
2070 png_bytep sp = row + (png_size_t)row_width * 2; |
|
2071 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2072 for (i = 0; i < row_width; i++) |
|
2073 { |
|
2074 *(--dp) = *(--sp); |
|
2075 *(--dp) = *(--sp); |
|
2076 *(--dp) = hi_filler; |
|
2077 *(--dp) = lo_filler; |
|
2078 } |
|
2079 row_info->channels = 2; |
|
2080 row_info->pixel_depth = 32; |
|
2081 row_info->rowbytes = row_width * 4; |
|
2082 } |
|
2083 } |
|
2084 } /* COLOR_TYPE == GRAY */ |
|
2085 else if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
2086 { |
|
2087 if (row_info->bit_depth == 8) |
|
2088 { |
|
2089 /* This changes the data from RGB to RGBX */ |
|
2090 if (flags & PNG_FLAG_FILLER_AFTER) |
|
2091 { |
|
2092 png_bytep sp = row + (png_size_t)row_width * 3; |
|
2093 png_bytep dp = sp + (png_size_t)row_width; |
|
2094 for (i = 1; i < row_width; i++) |
|
2095 { |
|
2096 *(--dp) = lo_filler; |
|
2097 *(--dp) = *(--sp); |
|
2098 *(--dp) = *(--sp); |
|
2099 *(--dp) = *(--sp); |
|
2100 } |
|
2101 *(--dp) = lo_filler; |
|
2102 row_info->channels = 4; |
|
2103 row_info->pixel_depth = 32; |
|
2104 row_info->rowbytes = row_width * 4; |
|
2105 } |
|
2106 /* This changes the data from RGB to XRGB */ |
|
2107 else |
|
2108 { |
|
2109 png_bytep sp = row + (png_size_t)row_width * 3; |
|
2110 png_bytep dp = sp + (png_size_t)row_width; |
|
2111 for (i = 0; i < row_width; i++) |
|
2112 { |
|
2113 *(--dp) = *(--sp); |
|
2114 *(--dp) = *(--sp); |
|
2115 *(--dp) = *(--sp); |
|
2116 *(--dp) = lo_filler; |
|
2117 } |
|
2118 row_info->channels = 4; |
|
2119 row_info->pixel_depth = 32; |
|
2120 row_info->rowbytes = row_width * 4; |
|
2121 } |
|
2122 } |
|
2123 else if (row_info->bit_depth == 16) |
|
2124 { |
|
2125 /* This changes the data from RRGGBB to RRGGBBXX */ |
|
2126 if (flags & PNG_FLAG_FILLER_AFTER) |
|
2127 { |
|
2128 png_bytep sp = row + (png_size_t)row_width * 6; |
|
2129 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2130 for (i = 1; i < row_width; i++) |
|
2131 { |
|
2132 *(--dp) = hi_filler; |
|
2133 *(--dp) = lo_filler; |
|
2134 *(--dp) = *(--sp); |
|
2135 *(--dp) = *(--sp); |
|
2136 *(--dp) = *(--sp); |
|
2137 *(--dp) = *(--sp); |
|
2138 *(--dp) = *(--sp); |
|
2139 *(--dp) = *(--sp); |
|
2140 } |
|
2141 *(--dp) = hi_filler; |
|
2142 *(--dp) = lo_filler; |
|
2143 row_info->channels = 4; |
|
2144 row_info->pixel_depth = 64; |
|
2145 row_info->rowbytes = row_width * 8; |
|
2146 } |
|
2147 /* This changes the data from RRGGBB to XXRRGGBB */ |
|
2148 else |
|
2149 { |
|
2150 png_bytep sp = row + (png_size_t)row_width * 6; |
|
2151 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2152 for (i = 0; i < row_width; i++) |
|
2153 { |
|
2154 *(--dp) = *(--sp); |
|
2155 *(--dp) = *(--sp); |
|
2156 *(--dp) = *(--sp); |
|
2157 *(--dp) = *(--sp); |
|
2158 *(--dp) = *(--sp); |
|
2159 *(--dp) = *(--sp); |
|
2160 *(--dp) = hi_filler; |
|
2161 *(--dp) = lo_filler; |
|
2162 } |
|
2163 row_info->channels = 4; |
|
2164 row_info->pixel_depth = 64; |
|
2165 row_info->rowbytes = row_width * 8; |
|
2166 } |
|
2167 } |
|
2168 } /* COLOR_TYPE == RGB */ |
|
2169 } |
|
2170 #endif |
|
2171 |
|
2172 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
2173 /* Expand grayscale files to RGB, with or without alpha */ |
|
2174 void /* PRIVATE */ |
|
2175 png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) |
|
2176 { |
|
2177 png_uint_32 i; |
|
2178 png_uint_32 row_width = row_info->width; |
|
2179 |
|
2180 png_debug(1, "in png_do_gray_to_rgb"); |
|
2181 if (row_info->bit_depth >= 8 && |
|
2182 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
2183 row != NULL && row_info != NULL && |
|
2184 #endif |
|
2185 !(row_info->color_type & PNG_COLOR_MASK_COLOR)) |
|
2186 { |
|
2187 if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
|
2188 { |
|
2189 if (row_info->bit_depth == 8) |
|
2190 { |
|
2191 png_bytep sp = row + (png_size_t)row_width - 1; |
|
2192 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2193 for (i = 0; i < row_width; i++) |
|
2194 { |
|
2195 *(dp--) = *sp; |
|
2196 *(dp--) = *sp; |
|
2197 *(dp--) = *(sp--); |
|
2198 } |
|
2199 } |
|
2200 else |
|
2201 { |
|
2202 png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
|
2203 png_bytep dp = sp + (png_size_t)row_width * 4; |
|
2204 for (i = 0; i < row_width; i++) |
|
2205 { |
|
2206 *(dp--) = *sp; |
|
2207 *(dp--) = *(sp - 1); |
|
2208 *(dp--) = *sp; |
|
2209 *(dp--) = *(sp - 1); |
|
2210 *(dp--) = *(sp--); |
|
2211 *(dp--) = *(sp--); |
|
2212 } |
|
2213 } |
|
2214 } |
|
2215 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
2216 { |
|
2217 if (row_info->bit_depth == 8) |
|
2218 { |
|
2219 png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
|
2220 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2221 for (i = 0; i < row_width; i++) |
|
2222 { |
|
2223 *(dp--) = *(sp--); |
|
2224 *(dp--) = *sp; |
|
2225 *(dp--) = *sp; |
|
2226 *(dp--) = *(sp--); |
|
2227 } |
|
2228 } |
|
2229 else |
|
2230 { |
|
2231 png_bytep sp = row + (png_size_t)row_width * 4 - 1; |
|
2232 png_bytep dp = sp + (png_size_t)row_width * 4; |
|
2233 for (i = 0; i < row_width; i++) |
|
2234 { |
|
2235 *(dp--) = *(sp--); |
|
2236 *(dp--) = *(sp--); |
|
2237 *(dp--) = *sp; |
|
2238 *(dp--) = *(sp - 1); |
|
2239 *(dp--) = *sp; |
|
2240 *(dp--) = *(sp - 1); |
|
2241 *(dp--) = *(sp--); |
|
2242 *(dp--) = *(sp--); |
|
2243 } |
|
2244 } |
|
2245 } |
|
2246 row_info->channels += (png_byte)2; |
|
2247 row_info->color_type |= PNG_COLOR_MASK_COLOR; |
|
2248 row_info->pixel_depth = (png_byte)(row_info->channels * |
|
2249 row_info->bit_depth); |
|
2250 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
2251 } |
|
2252 } |
|
2253 #endif |
|
2254 |
|
2255 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
2256 /* Reduce RGB files to grayscale, with or without alpha |
|
2257 * using the equation given in Poynton's ColorFAQ at |
|
2258 * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008) |
|
2259 * New link: |
|
2260 * <http://www.poynton.com/notes/colour_and_gamma/> |
|
2261 * Charles Poynton poynton at poynton.com |
|
2262 * |
|
2263 * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B |
|
2264 * |
|
2265 * We approximate this with |
|
2266 * |
|
2267 * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B |
|
2268 * |
|
2269 * which can be expressed with integers as |
|
2270 * |
|
2271 * Y = (6969 * R + 23434 * G + 2365 * B)/32768 |
|
2272 * |
|
2273 * The calculation is to be done in a linear colorspace. |
|
2274 * |
|
2275 * Other integer coefficents can be used via png_set_rgb_to_gray(). |
|
2276 */ |
|
2277 int /* PRIVATE */ |
|
2278 png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) |
|
2279 |
|
2280 { |
|
2281 png_uint_32 i; |
|
2282 |
|
2283 png_uint_32 row_width = row_info->width; |
|
2284 int rgb_error = 0; |
|
2285 |
|
2286 png_debug(1, "in png_do_rgb_to_gray"); |
|
2287 if ( |
|
2288 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
2289 row != NULL && row_info != NULL && |
|
2290 #endif |
|
2291 (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
|
2292 { |
|
2293 png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; |
|
2294 png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; |
|
2295 png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff; |
|
2296 |
|
2297 if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
2298 { |
|
2299 if (row_info->bit_depth == 8) |
|
2300 { |
|
2301 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2302 if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
|
2303 { |
|
2304 png_bytep sp = row; |
|
2305 png_bytep dp = row; |
|
2306 |
|
2307 for (i = 0; i < row_width; i++) |
|
2308 { |
|
2309 png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
|
2310 png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
|
2311 png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
|
2312 if (red != green || red != blue) |
|
2313 { |
|
2314 rgb_error |= 1; |
|
2315 *(dp++) = png_ptr->gamma_from_1[ |
|
2316 (rc*red + gc*green + bc*blue)>>15]; |
|
2317 } |
|
2318 else |
|
2319 *(dp++) = *(sp - 1); |
|
2320 } |
|
2321 } |
|
2322 else |
|
2323 #endif |
|
2324 { |
|
2325 png_bytep sp = row; |
|
2326 png_bytep dp = row; |
|
2327 for (i = 0; i < row_width; i++) |
|
2328 { |
|
2329 png_byte red = *(sp++); |
|
2330 png_byte green = *(sp++); |
|
2331 png_byte blue = *(sp++); |
|
2332 if (red != green || red != blue) |
|
2333 { |
|
2334 rgb_error |= 1; |
|
2335 *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); |
|
2336 } |
|
2337 else |
|
2338 *(dp++) = *(sp - 1); |
|
2339 } |
|
2340 } |
|
2341 } |
|
2342 |
|
2343 else /* RGB bit_depth == 16 */ |
|
2344 { |
|
2345 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2346 if (png_ptr->gamma_16_to_1 != NULL && |
|
2347 png_ptr->gamma_16_from_1 != NULL) |
|
2348 { |
|
2349 png_bytep sp = row; |
|
2350 png_bytep dp = row; |
|
2351 for (i = 0; i < row_width; i++) |
|
2352 { |
|
2353 png_uint_16 red, green, blue, w; |
|
2354 |
|
2355 red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2356 green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2357 blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2358 |
|
2359 if (red == green && red == blue) |
|
2360 w = red; |
|
2361 else |
|
2362 { |
|
2363 png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> |
|
2364 png_ptr->gamma_shift][red>>8]; |
|
2365 png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >> |
|
2366 png_ptr->gamma_shift][green>>8]; |
|
2367 png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> |
|
2368 png_ptr->gamma_shift][blue>>8]; |
|
2369 png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 |
|
2370 + bc*blue_1)>>15); |
|
2371 w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
|
2372 png_ptr->gamma_shift][gray16 >> 8]; |
|
2373 rgb_error |= 1; |
|
2374 } |
|
2375 |
|
2376 *(dp++) = (png_byte)((w>>8) & 0xff); |
|
2377 *(dp++) = (png_byte)(w & 0xff); |
|
2378 } |
|
2379 } |
|
2380 else |
|
2381 #endif |
|
2382 { |
|
2383 png_bytep sp = row; |
|
2384 png_bytep dp = row; |
|
2385 for (i = 0; i < row_width; i++) |
|
2386 { |
|
2387 png_uint_16 red, green, blue, gray16; |
|
2388 |
|
2389 red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2390 green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2391 blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2392 |
|
2393 if (red != green || red != blue) |
|
2394 rgb_error |= 1; |
|
2395 gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); |
|
2396 *(dp++) = (png_byte)((gray16>>8) & 0xff); |
|
2397 *(dp++) = (png_byte)(gray16 & 0xff); |
|
2398 } |
|
2399 } |
|
2400 } |
|
2401 } |
|
2402 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
2403 { |
|
2404 if (row_info->bit_depth == 8) |
|
2405 { |
|
2406 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2407 if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
|
2408 { |
|
2409 png_bytep sp = row; |
|
2410 png_bytep dp = row; |
|
2411 for (i = 0; i < row_width; i++) |
|
2412 { |
|
2413 png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
|
2414 png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
|
2415 png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
|
2416 if (red != green || red != blue) |
|
2417 rgb_error |= 1; |
|
2418 *(dp++) = png_ptr->gamma_from_1 |
|
2419 [(rc*red + gc*green + bc*blue)>>15]; |
|
2420 *(dp++) = *(sp++); /* alpha */ |
|
2421 } |
|
2422 } |
|
2423 else |
|
2424 #endif |
|
2425 { |
|
2426 png_bytep sp = row; |
|
2427 png_bytep dp = row; |
|
2428 for (i = 0; i < row_width; i++) |
|
2429 { |
|
2430 png_byte red = *(sp++); |
|
2431 png_byte green = *(sp++); |
|
2432 png_byte blue = *(sp++); |
|
2433 if (red != green || red != blue) |
|
2434 rgb_error |= 1; |
|
2435 *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); |
|
2436 *(dp++) = *(sp++); /* alpha */ |
|
2437 } |
|
2438 } |
|
2439 } |
|
2440 else /* RGBA bit_depth == 16 */ |
|
2441 { |
|
2442 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2443 if (png_ptr->gamma_16_to_1 != NULL && |
|
2444 png_ptr->gamma_16_from_1 != NULL) |
|
2445 { |
|
2446 png_bytep sp = row; |
|
2447 png_bytep dp = row; |
|
2448 for (i = 0; i < row_width; i++) |
|
2449 { |
|
2450 png_uint_16 red, green, blue, w; |
|
2451 |
|
2452 red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2453 green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2454 blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2455 |
|
2456 if (red == green && red == blue) |
|
2457 w = red; |
|
2458 else |
|
2459 { |
|
2460 png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> |
|
2461 png_ptr->gamma_shift][red>>8]; |
|
2462 png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >> |
|
2463 png_ptr->gamma_shift][green>>8]; |
|
2464 png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> |
|
2465 png_ptr->gamma_shift][blue>>8]; |
|
2466 png_uint_16 gray16 = (png_uint_16)((rc * red_1 |
|
2467 + gc * green_1 + bc * blue_1)>>15); |
|
2468 w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
|
2469 png_ptr->gamma_shift][gray16 >> 8]; |
|
2470 rgb_error |= 1; |
|
2471 } |
|
2472 |
|
2473 *(dp++) = (png_byte)((w>>8) & 0xff); |
|
2474 *(dp++) = (png_byte)(w & 0xff); |
|
2475 *(dp++) = *(sp++); /* alpha */ |
|
2476 *(dp++) = *(sp++); |
|
2477 } |
|
2478 } |
|
2479 else |
|
2480 #endif |
|
2481 { |
|
2482 png_bytep sp = row; |
|
2483 png_bytep dp = row; |
|
2484 for (i = 0; i < row_width; i++) |
|
2485 { |
|
2486 png_uint_16 red, green, blue, gray16; |
|
2487 red = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
|
2488 green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
|
2489 blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
|
2490 if (red != green || red != blue) |
|
2491 rgb_error |= 1; |
|
2492 gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); |
|
2493 *(dp++) = (png_byte)((gray16>>8) & 0xff); |
|
2494 *(dp++) = (png_byte)(gray16 & 0xff); |
|
2495 *(dp++) = *(sp++); /* alpha */ |
|
2496 *(dp++) = *(sp++); |
|
2497 } |
|
2498 } |
|
2499 } |
|
2500 } |
|
2501 row_info->channels -= (png_byte)2; |
|
2502 row_info->color_type &= ~PNG_COLOR_MASK_COLOR; |
|
2503 row_info->pixel_depth = (png_byte)(row_info->channels * |
|
2504 row_info->bit_depth); |
|
2505 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
2506 } |
|
2507 return rgb_error; |
|
2508 } |
|
2509 #endif |
|
2510 |
|
2511 /* Build a grayscale palette. Palette is assumed to be 1 << bit_depth |
|
2512 * large of png_color. This lets grayscale images be treated as |
|
2513 * paletted. Most useful for gamma correction and simplification |
|
2514 * of code. |
|
2515 */ |
|
2516 void PNGAPI |
|
2517 png_build_grayscale_palette(int bit_depth, png_colorp palette) |
|
2518 { |
|
2519 int num_palette; |
|
2520 int color_inc; |
|
2521 int i; |
|
2522 int v; |
|
2523 |
|
2524 png_debug(1, "in png_do_build_grayscale_palette"); |
|
2525 if (palette == NULL) |
|
2526 return; |
|
2527 |
|
2528 switch (bit_depth) |
|
2529 { |
|
2530 case 1: |
|
2531 num_palette = 2; |
|
2532 color_inc = 0xff; |
|
2533 break; |
|
2534 |
|
2535 case 2: |
|
2536 num_palette = 4; |
|
2537 color_inc = 0x55; |
|
2538 break; |
|
2539 |
|
2540 case 4: |
|
2541 num_palette = 16; |
|
2542 color_inc = 0x11; |
|
2543 break; |
|
2544 |
|
2545 case 8: |
|
2546 num_palette = 256; |
|
2547 color_inc = 1; |
|
2548 break; |
|
2549 |
|
2550 default: |
|
2551 num_palette = 0; |
|
2552 color_inc = 0; |
|
2553 break; |
|
2554 } |
|
2555 |
|
2556 for (i = 0, v = 0; i < num_palette; i++, v += color_inc) |
|
2557 { |
|
2558 palette[i].red = (png_byte)v; |
|
2559 palette[i].green = (png_byte)v; |
|
2560 palette[i].blue = (png_byte)v; |
|
2561 } |
|
2562 } |
|
2563 |
|
2564 /* This function is currently unused. Do we really need it? */ |
|
2565 #if defined(PNG_READ_DITHER_SUPPORTED) && defined(PNG_CORRECT_PALETTE_SUPPORTED) |
|
2566 void /* PRIVATE */ |
|
2567 png_correct_palette(png_structp png_ptr, png_colorp palette, |
|
2568 int num_palette) |
|
2569 { |
|
2570 png_debug(1, "in png_correct_palette"); |
|
2571 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ |
|
2572 defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED) |
|
2573 if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND)) |
|
2574 { |
|
2575 png_color back, back_1; |
|
2576 |
|
2577 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
|
2578 { |
|
2579 back.red = png_ptr->gamma_table[png_ptr->background.red]; |
|
2580 back.green = png_ptr->gamma_table[png_ptr->background.green]; |
|
2581 back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
|
2582 |
|
2583 back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
|
2584 back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
|
2585 back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
|
2586 } |
|
2587 else |
|
2588 { |
|
2589 double g; |
|
2590 |
|
2591 g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma); |
|
2592 |
|
2593 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN || |
|
2594 fabs(g - 1.0) < PNG_GAMMA_THRESHOLD) |
|
2595 { |
|
2596 back.red = png_ptr->background.red; |
|
2597 back.green = png_ptr->background.green; |
|
2598 back.blue = png_ptr->background.blue; |
|
2599 } |
|
2600 else |
|
2601 { |
|
2602 back.red = |
|
2603 (png_byte)(pow((double)png_ptr->background.red/255, g) * |
|
2604 255.0 + 0.5); |
|
2605 back.green = |
|
2606 (png_byte)(pow((double)png_ptr->background.green/255, g) * |
|
2607 255.0 + 0.5); |
|
2608 back.blue = |
|
2609 (png_byte)(pow((double)png_ptr->background.blue/255, g) * |
|
2610 255.0 + 0.5); |
|
2611 } |
|
2612 |
|
2613 g = 1.0 / png_ptr->background_gamma; |
|
2614 |
|
2615 back_1.red = |
|
2616 (png_byte)(pow((double)png_ptr->background.red/255, g) * |
|
2617 255.0 + 0.5); |
|
2618 back_1.green = |
|
2619 (png_byte)(pow((double)png_ptr->background.green/255, g) * |
|
2620 255.0 + 0.5); |
|
2621 back_1.blue = |
|
2622 (png_byte)(pow((double)png_ptr->background.blue/255, g) * |
|
2623 255.0 + 0.5); |
|
2624 } |
|
2625 |
|
2626 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
2627 { |
|
2628 png_uint_32 i; |
|
2629 |
|
2630 for (i = 0; i < (png_uint_32)num_palette; i++) |
|
2631 { |
|
2632 if (i < png_ptr->num_trans && png_ptr->trans[i] == 0) |
|
2633 { |
|
2634 palette[i] = back; |
|
2635 } |
|
2636 else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff) |
|
2637 { |
|
2638 png_byte v, w; |
|
2639 |
|
2640 v = png_ptr->gamma_to_1[png_ptr->palette[i].red]; |
|
2641 png_composite(w, v, png_ptr->trans[i], back_1.red); |
|
2642 palette[i].red = png_ptr->gamma_from_1[w]; |
|
2643 |
|
2644 v = png_ptr->gamma_to_1[png_ptr->palette[i].green]; |
|
2645 png_composite(w, v, png_ptr->trans[i], back_1.green); |
|
2646 palette[i].green = png_ptr->gamma_from_1[w]; |
|
2647 |
|
2648 v = png_ptr->gamma_to_1[png_ptr->palette[i].blue]; |
|
2649 png_composite(w, v, png_ptr->trans[i], back_1.blue); |
|
2650 palette[i].blue = png_ptr->gamma_from_1[w]; |
|
2651 } |
|
2652 else |
|
2653 { |
|
2654 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
2655 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
2656 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
2657 } |
|
2658 } |
|
2659 } |
|
2660 else |
|
2661 { |
|
2662 int i; |
|
2663 |
|
2664 for (i = 0; i < num_palette; i++) |
|
2665 { |
|
2666 if (palette[i].red == (png_byte)png_ptr->trans_values.gray) |
|
2667 { |
|
2668 palette[i] = back; |
|
2669 } |
|
2670 else |
|
2671 { |
|
2672 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
2673 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
2674 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
2675 } |
|
2676 } |
|
2677 } |
|
2678 } |
|
2679 else |
|
2680 #endif |
|
2681 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2682 if (png_ptr->transformations & PNG_GAMMA) |
|
2683 { |
|
2684 int i; |
|
2685 |
|
2686 for (i = 0; i < num_palette; i++) |
|
2687 { |
|
2688 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
2689 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
2690 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
2691 } |
|
2692 } |
|
2693 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2694 else |
|
2695 #endif |
|
2696 #endif |
|
2697 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2698 if (png_ptr->transformations & PNG_BACKGROUND) |
|
2699 { |
|
2700 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
2701 { |
|
2702 png_color back; |
|
2703 |
|
2704 back.red = (png_byte)png_ptr->background.red; |
|
2705 back.green = (png_byte)png_ptr->background.green; |
|
2706 back.blue = (png_byte)png_ptr->background.blue; |
|
2707 |
|
2708 for (i = 0; i < (int)png_ptr->num_trans; i++) |
|
2709 { |
|
2710 if (png_ptr->trans[i] == 0) |
|
2711 { |
|
2712 palette[i].red = back.red; |
|
2713 palette[i].green = back.green; |
|
2714 palette[i].blue = back.blue; |
|
2715 } |
|
2716 else if (png_ptr->trans[i] != 0xff) |
|
2717 { |
|
2718 png_composite(palette[i].red, png_ptr->palette[i].red, |
|
2719 png_ptr->trans[i], back.red); |
|
2720 png_composite(palette[i].green, png_ptr->palette[i].green, |
|
2721 png_ptr->trans[i], back.green); |
|
2722 png_composite(palette[i].blue, png_ptr->palette[i].blue, |
|
2723 png_ptr->trans[i], back.blue); |
|
2724 } |
|
2725 } |
|
2726 } |
|
2727 else /* Assume grayscale palette (what else could it be?) */ |
|
2728 { |
|
2729 int i; |
|
2730 |
|
2731 for (i = 0; i < num_palette; i++) |
|
2732 { |
|
2733 if (i == (png_byte)png_ptr->trans_values.gray) |
|
2734 { |
|
2735 palette[i].red = (png_byte)png_ptr->background.red; |
|
2736 palette[i].green = (png_byte)png_ptr->background.green; |
|
2737 palette[i].blue = (png_byte)png_ptr->background.blue; |
|
2738 } |
|
2739 } |
|
2740 } |
|
2741 } |
|
2742 #endif |
|
2743 } |
|
2744 #endif |
|
2745 |
|
2746 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2747 /* Replace any alpha or transparency with the supplied background color. |
|
2748 * "background" is already in the screen gamma, while "background_1" is |
|
2749 * at a gamma of 1.0. Paletted files have already been taken care of. |
|
2750 */ |
|
2751 void /* PRIVATE */ |
|
2752 png_do_background(png_row_infop row_info, png_bytep row, |
|
2753 png_color_16p trans_values, png_color_16p background |
|
2754 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2755 , png_color_16p background_1, |
|
2756 png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1, |
|
2757 png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1, |
|
2758 png_uint_16pp gamma_16_to_1, int gamma_shift |
|
2759 #endif |
|
2760 ) |
|
2761 { |
|
2762 png_bytep sp, dp; |
|
2763 png_uint_32 i; |
|
2764 png_uint_32 row_width=row_info->width; |
|
2765 int shift; |
|
2766 |
|
2767 png_debug(1, "in png_do_background"); |
|
2768 if (background != NULL && |
|
2769 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
2770 row != NULL && row_info != NULL && |
|
2771 #endif |
|
2772 (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) || |
|
2773 (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values))) |
|
2774 { |
|
2775 switch (row_info->color_type) |
|
2776 { |
|
2777 case PNG_COLOR_TYPE_GRAY: |
|
2778 { |
|
2779 switch (row_info->bit_depth) |
|
2780 { |
|
2781 case 1: |
|
2782 { |
|
2783 sp = row; |
|
2784 shift = 7; |
|
2785 for (i = 0; i < row_width; i++) |
|
2786 { |
|
2787 if ((png_uint_16)((*sp >> shift) & 0x01) |
|
2788 == trans_values->gray) |
|
2789 { |
|
2790 *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); |
|
2791 *sp |= (png_byte)(background->gray << shift); |
|
2792 } |
|
2793 if (!shift) |
|
2794 { |
|
2795 shift = 7; |
|
2796 sp++; |
|
2797 } |
|
2798 else |
|
2799 shift--; |
|
2800 } |
|
2801 break; |
|
2802 } |
|
2803 |
|
2804 case 2: |
|
2805 { |
|
2806 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2807 if (gamma_table != NULL) |
|
2808 { |
|
2809 sp = row; |
|
2810 shift = 6; |
|
2811 for (i = 0; i < row_width; i++) |
|
2812 { |
|
2813 if ((png_uint_16)((*sp >> shift) & 0x03) |
|
2814 == trans_values->gray) |
|
2815 { |
|
2816 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
|
2817 *sp |= (png_byte)(background->gray << shift); |
|
2818 } |
|
2819 else |
|
2820 { |
|
2821 png_byte p = (png_byte)((*sp >> shift) & 0x03); |
|
2822 png_byte g = (png_byte)((gamma_table [p | (p << 2) | |
|
2823 (p << 4) | (p << 6)] >> 6) & 0x03); |
|
2824 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
|
2825 *sp |= (png_byte)(g << shift); |
|
2826 } |
|
2827 if (!shift) |
|
2828 { |
|
2829 shift = 6; |
|
2830 sp++; |
|
2831 } |
|
2832 else |
|
2833 shift -= 2; |
|
2834 } |
|
2835 } |
|
2836 else |
|
2837 #endif |
|
2838 { |
|
2839 sp = row; |
|
2840 shift = 6; |
|
2841 for (i = 0; i < row_width; i++) |
|
2842 { |
|
2843 if ((png_uint_16)((*sp >> shift) & 0x03) |
|
2844 == trans_values->gray) |
|
2845 { |
|
2846 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
|
2847 *sp |= (png_byte)(background->gray << shift); |
|
2848 } |
|
2849 if (!shift) |
|
2850 { |
|
2851 shift = 6; |
|
2852 sp++; |
|
2853 } |
|
2854 else |
|
2855 shift -= 2; |
|
2856 } |
|
2857 } |
|
2858 break; |
|
2859 } |
|
2860 |
|
2861 case 4: |
|
2862 { |
|
2863 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2864 if (gamma_table != NULL) |
|
2865 { |
|
2866 sp = row; |
|
2867 shift = 4; |
|
2868 for (i = 0; i < row_width; i++) |
|
2869 { |
|
2870 if ((png_uint_16)((*sp >> shift) & 0x0f) |
|
2871 == trans_values->gray) |
|
2872 { |
|
2873 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
|
2874 *sp |= (png_byte)(background->gray << shift); |
|
2875 } |
|
2876 else |
|
2877 { |
|
2878 png_byte p = (png_byte)((*sp >> shift) & 0x0f); |
|
2879 png_byte g = (png_byte)((gamma_table[p | |
|
2880 (p << 4)] >> 4) & 0x0f); |
|
2881 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
|
2882 *sp |= (png_byte)(g << shift); |
|
2883 } |
|
2884 if (!shift) |
|
2885 { |
|
2886 shift = 4; |
|
2887 sp++; |
|
2888 } |
|
2889 else |
|
2890 shift -= 4; |
|
2891 } |
|
2892 } |
|
2893 else |
|
2894 #endif |
|
2895 { |
|
2896 sp = row; |
|
2897 shift = 4; |
|
2898 for (i = 0; i < row_width; i++) |
|
2899 { |
|
2900 if ((png_uint_16)((*sp >> shift) & 0x0f) |
|
2901 == trans_values->gray) |
|
2902 { |
|
2903 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
|
2904 *sp |= (png_byte)(background->gray << shift); |
|
2905 } |
|
2906 if (!shift) |
|
2907 { |
|
2908 shift = 4; |
|
2909 sp++; |
|
2910 } |
|
2911 else |
|
2912 shift -= 4; |
|
2913 } |
|
2914 } |
|
2915 break; |
|
2916 } |
|
2917 |
|
2918 case 8: |
|
2919 { |
|
2920 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2921 if (gamma_table != NULL) |
|
2922 { |
|
2923 sp = row; |
|
2924 for (i = 0; i < row_width; i++, sp++) |
|
2925 { |
|
2926 if (*sp == trans_values->gray) |
|
2927 { |
|
2928 *sp = (png_byte)background->gray; |
|
2929 } |
|
2930 else |
|
2931 { |
|
2932 *sp = gamma_table[*sp]; |
|
2933 } |
|
2934 } |
|
2935 } |
|
2936 else |
|
2937 #endif |
|
2938 { |
|
2939 sp = row; |
|
2940 for (i = 0; i < row_width; i++, sp++) |
|
2941 { |
|
2942 if (*sp == trans_values->gray) |
|
2943 { |
|
2944 *sp = (png_byte)background->gray; |
|
2945 } |
|
2946 } |
|
2947 } |
|
2948 break; |
|
2949 } |
|
2950 |
|
2951 case 16: |
|
2952 { |
|
2953 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2954 if (gamma_16 != NULL) |
|
2955 { |
|
2956 sp = row; |
|
2957 for (i = 0; i < row_width; i++, sp += 2) |
|
2958 { |
|
2959 png_uint_16 v; |
|
2960 |
|
2961 v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
2962 if (v == trans_values->gray) |
|
2963 { |
|
2964 /* Background is already in screen gamma */ |
|
2965 *sp = (png_byte)((background->gray >> 8) & 0xff); |
|
2966 *(sp + 1) = (png_byte)(background->gray & 0xff); |
|
2967 } |
|
2968 else |
|
2969 { |
|
2970 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
2971 *sp = (png_byte)((v >> 8) & 0xff); |
|
2972 *(sp + 1) = (png_byte)(v & 0xff); |
|
2973 } |
|
2974 } |
|
2975 } |
|
2976 else |
|
2977 #endif |
|
2978 { |
|
2979 sp = row; |
|
2980 for (i = 0; i < row_width; i++, sp += 2) |
|
2981 { |
|
2982 png_uint_16 v; |
|
2983 |
|
2984 v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
2985 if (v == trans_values->gray) |
|
2986 { |
|
2987 *sp = (png_byte)((background->gray >> 8) & 0xff); |
|
2988 *(sp + 1) = (png_byte)(background->gray & 0xff); |
|
2989 } |
|
2990 } |
|
2991 } |
|
2992 break; |
|
2993 } |
|
2994 } |
|
2995 break; |
|
2996 } |
|
2997 |
|
2998 case PNG_COLOR_TYPE_RGB: |
|
2999 { |
|
3000 if (row_info->bit_depth == 8) |
|
3001 { |
|
3002 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3003 if (gamma_table != NULL) |
|
3004 { |
|
3005 sp = row; |
|
3006 for (i = 0; i < row_width; i++, sp += 3) |
|
3007 { |
|
3008 if (*sp == trans_values->red && |
|
3009 *(sp + 1) == trans_values->green && |
|
3010 *(sp + 2) == trans_values->blue) |
|
3011 { |
|
3012 *sp = (png_byte)background->red; |
|
3013 *(sp + 1) = (png_byte)background->green; |
|
3014 *(sp + 2) = (png_byte)background->blue; |
|
3015 } |
|
3016 else |
|
3017 { |
|
3018 *sp = gamma_table[*sp]; |
|
3019 *(sp + 1) = gamma_table[*(sp + 1)]; |
|
3020 *(sp + 2) = gamma_table[*(sp + 2)]; |
|
3021 } |
|
3022 } |
|
3023 } |
|
3024 else |
|
3025 #endif |
|
3026 { |
|
3027 sp = row; |
|
3028 for (i = 0; i < row_width; i++, sp += 3) |
|
3029 { |
|
3030 if (*sp == trans_values->red && |
|
3031 *(sp + 1) == trans_values->green && |
|
3032 *(sp + 2) == trans_values->blue) |
|
3033 { |
|
3034 *sp = (png_byte)background->red; |
|
3035 *(sp + 1) = (png_byte)background->green; |
|
3036 *(sp + 2) = (png_byte)background->blue; |
|
3037 } |
|
3038 } |
|
3039 } |
|
3040 } |
|
3041 else /* if (row_info->bit_depth == 16) */ |
|
3042 { |
|
3043 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3044 if (gamma_16 != NULL) |
|
3045 { |
|
3046 sp = row; |
|
3047 for (i = 0; i < row_width; i++, sp += 6) |
|
3048 { |
|
3049 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
3050 png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
|
3051 png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5)); |
|
3052 if (r == trans_values->red && g == trans_values->green && |
|
3053 b == trans_values->blue) |
|
3054 { |
|
3055 /* Background is already in screen gamma */ |
|
3056 *sp = (png_byte)((background->red >> 8) & 0xff); |
|
3057 *(sp + 1) = (png_byte)(background->red & 0xff); |
|
3058 *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); |
|
3059 *(sp + 3) = (png_byte)(background->green & 0xff); |
|
3060 *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
|
3061 *(sp + 5) = (png_byte)(background->blue & 0xff); |
|
3062 } |
|
3063 else |
|
3064 { |
|
3065 png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
3066 *sp = (png_byte)((v >> 8) & 0xff); |
|
3067 *(sp + 1) = (png_byte)(v & 0xff); |
|
3068 v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
|
3069 *(sp + 2) = (png_byte)((v >> 8) & 0xff); |
|
3070 *(sp + 3) = (png_byte)(v & 0xff); |
|
3071 v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
|
3072 *(sp + 4) = (png_byte)((v >> 8) & 0xff); |
|
3073 *(sp + 5) = (png_byte)(v & 0xff); |
|
3074 } |
|
3075 } |
|
3076 } |
|
3077 else |
|
3078 #endif |
|
3079 { |
|
3080 sp = row; |
|
3081 for (i = 0; i < row_width; i++, sp += 6) |
|
3082 { |
|
3083 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp+1)); |
|
3084 png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
|
3085 png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5)); |
|
3086 |
|
3087 if (r == trans_values->red && g == trans_values->green && |
|
3088 b == trans_values->blue) |
|
3089 { |
|
3090 *sp = (png_byte)((background->red >> 8) & 0xff); |
|
3091 *(sp + 1) = (png_byte)(background->red & 0xff); |
|
3092 *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); |
|
3093 *(sp + 3) = (png_byte)(background->green & 0xff); |
|
3094 *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
|
3095 *(sp + 5) = (png_byte)(background->blue & 0xff); |
|
3096 } |
|
3097 } |
|
3098 } |
|
3099 } |
|
3100 break; |
|
3101 } |
|
3102 |
|
3103 case PNG_COLOR_TYPE_GRAY_ALPHA: |
|
3104 { |
|
3105 if (row_info->bit_depth == 8) |
|
3106 { |
|
3107 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3108 if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
|
3109 gamma_table != NULL) |
|
3110 { |
|
3111 sp = row; |
|
3112 dp = row; |
|
3113 for (i = 0; i < row_width; i++, sp += 2, dp++) |
|
3114 { |
|
3115 png_uint_16 a = *(sp + 1); |
|
3116 |
|
3117 if (a == 0xff) |
|
3118 { |
|
3119 *dp = gamma_table[*sp]; |
|
3120 } |
|
3121 else if (a == 0) |
|
3122 { |
|
3123 /* Background is already in screen gamma */ |
|
3124 *dp = (png_byte)background->gray; |
|
3125 } |
|
3126 else |
|
3127 { |
|
3128 png_byte v, w; |
|
3129 |
|
3130 v = gamma_to_1[*sp]; |
|
3131 png_composite(w, v, a, background_1->gray); |
|
3132 *dp = gamma_from_1[w]; |
|
3133 } |
|
3134 } |
|
3135 } |
|
3136 else |
|
3137 #endif |
|
3138 { |
|
3139 sp = row; |
|
3140 dp = row; |
|
3141 for (i = 0; i < row_width; i++, sp += 2, dp++) |
|
3142 { |
|
3143 png_byte a = *(sp + 1); |
|
3144 |
|
3145 if (a == 0xff) |
|
3146 { |
|
3147 *dp = *sp; |
|
3148 } |
|
3149 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3150 else if (a == 0) |
|
3151 { |
|
3152 *dp = (png_byte)background->gray; |
|
3153 } |
|
3154 else |
|
3155 { |
|
3156 png_composite(*dp, *sp, a, background_1->gray); |
|
3157 } |
|
3158 #else |
|
3159 *dp = (png_byte)background->gray; |
|
3160 #endif |
|
3161 } |
|
3162 } |
|
3163 } |
|
3164 else /* if (png_ptr->bit_depth == 16) */ |
|
3165 { |
|
3166 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3167 if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
|
3168 gamma_16_to_1 != NULL) |
|
3169 { |
|
3170 sp = row; |
|
3171 dp = row; |
|
3172 for (i = 0; i < row_width; i++, sp += 4, dp += 2) |
|
3173 { |
|
3174 png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
|
3175 |
|
3176 if (a == (png_uint_16)0xffff) |
|
3177 { |
|
3178 png_uint_16 v; |
|
3179 |
|
3180 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
3181 *dp = (png_byte)((v >> 8) & 0xff); |
|
3182 *(dp + 1) = (png_byte)(v & 0xff); |
|
3183 } |
|
3184 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3185 else if (a == 0) |
|
3186 #else |
|
3187 else |
|
3188 #endif |
|
3189 { |
|
3190 /* Background is already in screen gamma */ |
|
3191 *dp = (png_byte)((background->gray >> 8) & 0xff); |
|
3192 *(dp + 1) = (png_byte)(background->gray & 0xff); |
|
3193 } |
|
3194 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3195 else |
|
3196 { |
|
3197 png_uint_16 g, v, w; |
|
3198 |
|
3199 g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
|
3200 png_composite_16(v, g, a, background_1->gray); |
|
3201 w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; |
|
3202 *dp = (png_byte)((w >> 8) & 0xff); |
|
3203 *(dp + 1) = (png_byte)(w & 0xff); |
|
3204 } |
|
3205 #endif |
|
3206 } |
|
3207 } |
|
3208 else |
|
3209 #endif |
|
3210 { |
|
3211 sp = row; |
|
3212 dp = row; |
|
3213 for (i = 0; i < row_width; i++, sp += 4, dp += 2) |
|
3214 { |
|
3215 png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
|
3216 if (a == (png_uint_16)0xffff) |
|
3217 { |
|
3218 png_memcpy(dp, sp, 2); |
|
3219 } |
|
3220 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3221 else if (a == 0) |
|
3222 #else |
|
3223 else |
|
3224 #endif |
|
3225 { |
|
3226 *dp = (png_byte)((background->gray >> 8) & 0xff); |
|
3227 *(dp + 1) = (png_byte)(background->gray & 0xff); |
|
3228 } |
|
3229 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3230 else |
|
3231 { |
|
3232 png_uint_16 g, v; |
|
3233 |
|
3234 g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
3235 png_composite_16(v, g, a, background_1->gray); |
|
3236 *dp = (png_byte)((v >> 8) & 0xff); |
|
3237 *(dp + 1) = (png_byte)(v & 0xff); |
|
3238 } |
|
3239 #endif |
|
3240 } |
|
3241 } |
|
3242 } |
|
3243 break; |
|
3244 } |
|
3245 |
|
3246 case PNG_COLOR_TYPE_RGB_ALPHA: |
|
3247 { |
|
3248 if (row_info->bit_depth == 8) |
|
3249 { |
|
3250 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3251 if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
|
3252 gamma_table != NULL) |
|
3253 { |
|
3254 sp = row; |
|
3255 dp = row; |
|
3256 for (i = 0; i < row_width; i++, sp += 4, dp += 3) |
|
3257 { |
|
3258 png_byte a = *(sp + 3); |
|
3259 |
|
3260 if (a == 0xff) |
|
3261 { |
|
3262 *dp = gamma_table[*sp]; |
|
3263 *(dp + 1) = gamma_table[*(sp + 1)]; |
|
3264 *(dp + 2) = gamma_table[*(sp + 2)]; |
|
3265 } |
|
3266 else if (a == 0) |
|
3267 { |
|
3268 /* Background is already in screen gamma */ |
|
3269 *dp = (png_byte)background->red; |
|
3270 *(dp + 1) = (png_byte)background->green; |
|
3271 *(dp + 2) = (png_byte)background->blue; |
|
3272 } |
|
3273 else |
|
3274 { |
|
3275 png_byte v, w; |
|
3276 |
|
3277 v = gamma_to_1[*sp]; |
|
3278 png_composite(w, v, a, background_1->red); |
|
3279 *dp = gamma_from_1[w]; |
|
3280 v = gamma_to_1[*(sp + 1)]; |
|
3281 png_composite(w, v, a, background_1->green); |
|
3282 *(dp + 1) = gamma_from_1[w]; |
|
3283 v = gamma_to_1[*(sp + 2)]; |
|
3284 png_composite(w, v, a, background_1->blue); |
|
3285 *(dp + 2) = gamma_from_1[w]; |
|
3286 } |
|
3287 } |
|
3288 } |
|
3289 else |
|
3290 #endif |
|
3291 { |
|
3292 sp = row; |
|
3293 dp = row; |
|
3294 for (i = 0; i < row_width; i++, sp += 4, dp += 3) |
|
3295 { |
|
3296 png_byte a = *(sp + 3); |
|
3297 |
|
3298 if (a == 0xff) |
|
3299 { |
|
3300 *dp = *sp; |
|
3301 *(dp + 1) = *(sp + 1); |
|
3302 *(dp + 2) = *(sp + 2); |
|
3303 } |
|
3304 else if (a == 0) |
|
3305 { |
|
3306 *dp = (png_byte)background->red; |
|
3307 *(dp + 1) = (png_byte)background->green; |
|
3308 *(dp + 2) = (png_byte)background->blue; |
|
3309 } |
|
3310 else |
|
3311 { |
|
3312 png_composite(*dp, *sp, a, background->red); |
|
3313 png_composite(*(dp + 1), *(sp + 1), a, |
|
3314 background->green); |
|
3315 png_composite(*(dp + 2), *(sp + 2), a, |
|
3316 background->blue); |
|
3317 } |
|
3318 } |
|
3319 } |
|
3320 } |
|
3321 else /* if (row_info->bit_depth == 16) */ |
|
3322 { |
|
3323 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3324 if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
|
3325 gamma_16_to_1 != NULL) |
|
3326 { |
|
3327 sp = row; |
|
3328 dp = row; |
|
3329 for (i = 0; i < row_width; i++, sp += 8, dp += 6) |
|
3330 { |
|
3331 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
|
3332 << 8) + (png_uint_16)(*(sp + 7))); |
|
3333 if (a == (png_uint_16)0xffff) |
|
3334 { |
|
3335 png_uint_16 v; |
|
3336 |
|
3337 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
3338 *dp = (png_byte)((v >> 8) & 0xff); |
|
3339 *(dp + 1) = (png_byte)(v & 0xff); |
|
3340 v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
|
3341 *(dp + 2) = (png_byte)((v >> 8) & 0xff); |
|
3342 *(dp + 3) = (png_byte)(v & 0xff); |
|
3343 v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
|
3344 *(dp + 4) = (png_byte)((v >> 8) & 0xff); |
|
3345 *(dp + 5) = (png_byte)(v & 0xff); |
|
3346 } |
|
3347 else if (a == 0) |
|
3348 { |
|
3349 /* Background is already in screen gamma */ |
|
3350 *dp = (png_byte)((background->red >> 8) & 0xff); |
|
3351 *(dp + 1) = (png_byte)(background->red & 0xff); |
|
3352 *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); |
|
3353 *(dp + 3) = (png_byte)(background->green & 0xff); |
|
3354 *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
|
3355 *(dp + 5) = (png_byte)(background->blue & 0xff); |
|
3356 } |
|
3357 else |
|
3358 { |
|
3359 png_uint_16 v, w, x; |
|
3360 |
|
3361 v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
|
3362 png_composite_16(w, v, a, background_1->red); |
|
3363 x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; |
|
3364 *dp = (png_byte)((x >> 8) & 0xff); |
|
3365 *(dp + 1) = (png_byte)(x & 0xff); |
|
3366 v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
|
3367 png_composite_16(w, v, a, background_1->green); |
|
3368 x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; |
|
3369 *(dp + 2) = (png_byte)((x >> 8) & 0xff); |
|
3370 *(dp + 3) = (png_byte)(x & 0xff); |
|
3371 v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
|
3372 png_composite_16(w, v, a, background_1->blue); |
|
3373 x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8]; |
|
3374 *(dp + 4) = (png_byte)((x >> 8) & 0xff); |
|
3375 *(dp + 5) = (png_byte)(x & 0xff); |
|
3376 } |
|
3377 } |
|
3378 } |
|
3379 else |
|
3380 #endif |
|
3381 { |
|
3382 sp = row; |
|
3383 dp = row; |
|
3384 for (i = 0; i < row_width; i++, sp += 8, dp += 6) |
|
3385 { |
|
3386 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
|
3387 << 8) + (png_uint_16)(*(sp + 7))); |
|
3388 if (a == (png_uint_16)0xffff) |
|
3389 { |
|
3390 png_memcpy(dp, sp, 6); |
|
3391 } |
|
3392 else if (a == 0) |
|
3393 { |
|
3394 *dp = (png_byte)((background->red >> 8) & 0xff); |
|
3395 *(dp + 1) = (png_byte)(background->red & 0xff); |
|
3396 *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); |
|
3397 *(dp + 3) = (png_byte)(background->green & 0xff); |
|
3398 *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
|
3399 *(dp + 5) = (png_byte)(background->blue & 0xff); |
|
3400 } |
|
3401 else |
|
3402 { |
|
3403 png_uint_16 v; |
|
3404 |
|
3405 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
3406 png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) |
|
3407 + *(sp + 3)); |
|
3408 png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) |
|
3409 + *(sp + 5)); |
|
3410 |
|
3411 png_composite_16(v, r, a, background->red); |
|
3412 *dp = (png_byte)((v >> 8) & 0xff); |
|
3413 *(dp + 1) = (png_byte)(v & 0xff); |
|
3414 png_composite_16(v, g, a, background->green); |
|
3415 *(dp + 2) = (png_byte)((v >> 8) & 0xff); |
|
3416 *(dp + 3) = (png_byte)(v & 0xff); |
|
3417 png_composite_16(v, b, a, background->blue); |
|
3418 *(dp + 4) = (png_byte)((v >> 8) & 0xff); |
|
3419 *(dp + 5) = (png_byte)(v & 0xff); |
|
3420 } |
|
3421 } |
|
3422 } |
|
3423 } |
|
3424 break; |
|
3425 } |
|
3426 } |
|
3427 |
|
3428 if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
|
3429 { |
|
3430 row_info->color_type &= ~PNG_COLOR_MASK_ALPHA; |
|
3431 row_info->channels--; |
|
3432 row_info->pixel_depth = (png_byte)(row_info->channels * |
|
3433 row_info->bit_depth); |
|
3434 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
3435 } |
|
3436 } |
|
3437 } |
|
3438 #endif |
|
3439 |
|
3440 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3441 /* Gamma correct the image, avoiding the alpha channel. Make sure |
|
3442 * you do this after you deal with the transparency issue on grayscale |
|
3443 * or RGB images. If your bit depth is 8, use gamma_table, if it |
|
3444 * is 16, use gamma_16_table and gamma_shift. Build these with |
|
3445 * build_gamma_table(). |
|
3446 */ |
|
3447 void /* PRIVATE */ |
|
3448 png_do_gamma(png_row_infop row_info, png_bytep row, |
|
3449 png_bytep gamma_table, png_uint_16pp gamma_16_table, |
|
3450 int gamma_shift) |
|
3451 { |
|
3452 png_bytep sp; |
|
3453 png_uint_32 i; |
|
3454 png_uint_32 row_width=row_info->width; |
|
3455 |
|
3456 png_debug(1, "in png_do_gamma"); |
|
3457 if ( |
|
3458 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
3459 row != NULL && row_info != NULL && |
|
3460 #endif |
|
3461 ((row_info->bit_depth <= 8 && gamma_table != NULL) || |
|
3462 (row_info->bit_depth == 16 && gamma_16_table != NULL))) |
|
3463 { |
|
3464 switch (row_info->color_type) |
|
3465 { |
|
3466 case PNG_COLOR_TYPE_RGB: |
|
3467 { |
|
3468 if (row_info->bit_depth == 8) |
|
3469 { |
|
3470 sp = row; |
|
3471 for (i = 0; i < row_width; i++) |
|
3472 { |
|
3473 *sp = gamma_table[*sp]; |
|
3474 sp++; |
|
3475 *sp = gamma_table[*sp]; |
|
3476 sp++; |
|
3477 *sp = gamma_table[*sp]; |
|
3478 sp++; |
|
3479 } |
|
3480 } |
|
3481 else /* if (row_info->bit_depth == 16) */ |
|
3482 { |
|
3483 sp = row; |
|
3484 for (i = 0; i < row_width; i++) |
|
3485 { |
|
3486 png_uint_16 v; |
|
3487 |
|
3488 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3489 *sp = (png_byte)((v >> 8) & 0xff); |
|
3490 *(sp + 1) = (png_byte)(v & 0xff); |
|
3491 sp += 2; |
|
3492 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3493 *sp = (png_byte)((v >> 8) & 0xff); |
|
3494 *(sp + 1) = (png_byte)(v & 0xff); |
|
3495 sp += 2; |
|
3496 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3497 *sp = (png_byte)((v >> 8) & 0xff); |
|
3498 *(sp + 1) = (png_byte)(v & 0xff); |
|
3499 sp += 2; |
|
3500 } |
|
3501 } |
|
3502 break; |
|
3503 } |
|
3504 |
|
3505 case PNG_COLOR_TYPE_RGB_ALPHA: |
|
3506 { |
|
3507 if (row_info->bit_depth == 8) |
|
3508 { |
|
3509 sp = row; |
|
3510 for (i = 0; i < row_width; i++) |
|
3511 { |
|
3512 *sp = gamma_table[*sp]; |
|
3513 sp++; |
|
3514 *sp = gamma_table[*sp]; |
|
3515 sp++; |
|
3516 *sp = gamma_table[*sp]; |
|
3517 sp++; |
|
3518 sp++; |
|
3519 } |
|
3520 } |
|
3521 else /* if (row_info->bit_depth == 16) */ |
|
3522 { |
|
3523 sp = row; |
|
3524 for (i = 0; i < row_width; i++) |
|
3525 { |
|
3526 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3527 *sp = (png_byte)((v >> 8) & 0xff); |
|
3528 *(sp + 1) = (png_byte)(v & 0xff); |
|
3529 sp += 2; |
|
3530 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3531 *sp = (png_byte)((v >> 8) & 0xff); |
|
3532 *(sp + 1) = (png_byte)(v & 0xff); |
|
3533 sp += 2; |
|
3534 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3535 *sp = (png_byte)((v >> 8) & 0xff); |
|
3536 *(sp + 1) = (png_byte)(v & 0xff); |
|
3537 sp += 4; |
|
3538 } |
|
3539 } |
|
3540 break; |
|
3541 } |
|
3542 |
|
3543 case PNG_COLOR_TYPE_GRAY_ALPHA: |
|
3544 { |
|
3545 if (row_info->bit_depth == 8) |
|
3546 { |
|
3547 sp = row; |
|
3548 for (i = 0; i < row_width; i++) |
|
3549 { |
|
3550 *sp = gamma_table[*sp]; |
|
3551 sp += 2; |
|
3552 } |
|
3553 } |
|
3554 else /* if (row_info->bit_depth == 16) */ |
|
3555 { |
|
3556 sp = row; |
|
3557 for (i = 0; i < row_width; i++) |
|
3558 { |
|
3559 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3560 *sp = (png_byte)((v >> 8) & 0xff); |
|
3561 *(sp + 1) = (png_byte)(v & 0xff); |
|
3562 sp += 4; |
|
3563 } |
|
3564 } |
|
3565 break; |
|
3566 } |
|
3567 |
|
3568 case PNG_COLOR_TYPE_GRAY: |
|
3569 { |
|
3570 if (row_info->bit_depth == 2) |
|
3571 { |
|
3572 sp = row; |
|
3573 for (i = 0; i < row_width; i += 4) |
|
3574 { |
|
3575 int a = *sp & 0xc0; |
|
3576 int b = *sp & 0x30; |
|
3577 int c = *sp & 0x0c; |
|
3578 int d = *sp & 0x03; |
|
3579 |
|
3580 *sp = (png_byte)( |
|
3581 ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| |
|
3582 ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| |
|
3583 ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| |
|
3584 ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) )); |
|
3585 sp++; |
|
3586 } |
|
3587 } |
|
3588 |
|
3589 if (row_info->bit_depth == 4) |
|
3590 { |
|
3591 sp = row; |
|
3592 for (i = 0; i < row_width; i += 2) |
|
3593 { |
|
3594 int msb = *sp & 0xf0; |
|
3595 int lsb = *sp & 0x0f; |
|
3596 |
|
3597 *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0) |
|
3598 | (((int)gamma_table[(lsb << 4) | lsb]) >> 4)); |
|
3599 sp++; |
|
3600 } |
|
3601 } |
|
3602 |
|
3603 else if (row_info->bit_depth == 8) |
|
3604 { |
|
3605 sp = row; |
|
3606 for (i = 0; i < row_width; i++) |
|
3607 { |
|
3608 *sp = gamma_table[*sp]; |
|
3609 sp++; |
|
3610 } |
|
3611 } |
|
3612 |
|
3613 else if (row_info->bit_depth == 16) |
|
3614 { |
|
3615 sp = row; |
|
3616 for (i = 0; i < row_width; i++) |
|
3617 { |
|
3618 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3619 *sp = (png_byte)((v >> 8) & 0xff); |
|
3620 *(sp + 1) = (png_byte)(v & 0xff); |
|
3621 sp += 2; |
|
3622 } |
|
3623 } |
|
3624 break; |
|
3625 } |
|
3626 } |
|
3627 } |
|
3628 } |
|
3629 #endif |
|
3630 |
|
3631 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
3632 /* Expands a palette row to an RGB or RGBA row depending |
|
3633 * upon whether you supply trans and num_trans. |
|
3634 */ |
|
3635 void /* PRIVATE */ |
|
3636 png_do_expand_palette(png_row_infop row_info, png_bytep row, |
|
3637 png_colorp palette, png_bytep trans, int num_trans) |
|
3638 { |
|
3639 int shift, value; |
|
3640 png_bytep sp, dp; |
|
3641 png_uint_32 i; |
|
3642 png_uint_32 row_width=row_info->width; |
|
3643 |
|
3644 png_debug(1, "in png_do_expand_palette"); |
|
3645 if ( |
|
3646 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
3647 row != NULL && row_info != NULL && |
|
3648 #endif |
|
3649 row_info->color_type == PNG_COLOR_TYPE_PALETTE) |
|
3650 { |
|
3651 if (row_info->bit_depth < 8) |
|
3652 { |
|
3653 switch (row_info->bit_depth) |
|
3654 { |
|
3655 case 1: |
|
3656 { |
|
3657 sp = row + (png_size_t)((row_width - 1) >> 3); |
|
3658 dp = row + (png_size_t)row_width - 1; |
|
3659 shift = 7 - (int)((row_width + 7) & 0x07); |
|
3660 for (i = 0; i < row_width; i++) |
|
3661 { |
|
3662 if ((*sp >> shift) & 0x01) |
|
3663 *dp = 1; |
|
3664 else |
|
3665 *dp = 0; |
|
3666 if (shift == 7) |
|
3667 { |
|
3668 shift = 0; |
|
3669 sp--; |
|
3670 } |
|
3671 else |
|
3672 shift++; |
|
3673 |
|
3674 dp--; |
|
3675 } |
|
3676 break; |
|
3677 } |
|
3678 |
|
3679 case 2: |
|
3680 { |
|
3681 sp = row + (png_size_t)((row_width - 1) >> 2); |
|
3682 dp = row + (png_size_t)row_width - 1; |
|
3683 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
|
3684 for (i = 0; i < row_width; i++) |
|
3685 { |
|
3686 value = (*sp >> shift) & 0x03; |
|
3687 *dp = (png_byte)value; |
|
3688 if (shift == 6) |
|
3689 { |
|
3690 shift = 0; |
|
3691 sp--; |
|
3692 } |
|
3693 else |
|
3694 shift += 2; |
|
3695 |
|
3696 dp--; |
|
3697 } |
|
3698 break; |
|
3699 } |
|
3700 |
|
3701 case 4: |
|
3702 { |
|
3703 sp = row + (png_size_t)((row_width - 1) >> 1); |
|
3704 dp = row + (png_size_t)row_width - 1; |
|
3705 shift = (int)((row_width & 0x01) << 2); |
|
3706 for (i = 0; i < row_width; i++) |
|
3707 { |
|
3708 value = (*sp >> shift) & 0x0f; |
|
3709 *dp = (png_byte)value; |
|
3710 if (shift == 4) |
|
3711 { |
|
3712 shift = 0; |
|
3713 sp--; |
|
3714 } |
|
3715 else |
|
3716 shift += 4; |
|
3717 |
|
3718 dp--; |
|
3719 } |
|
3720 break; |
|
3721 } |
|
3722 } |
|
3723 row_info->bit_depth = 8; |
|
3724 row_info->pixel_depth = 8; |
|
3725 row_info->rowbytes = row_width; |
|
3726 } |
|
3727 switch (row_info->bit_depth) |
|
3728 { |
|
3729 case 8: |
|
3730 { |
|
3731 if (trans != NULL) |
|
3732 { |
|
3733 sp = row + (png_size_t)row_width - 1; |
|
3734 dp = row + (png_size_t)(row_width << 2) - 1; |
|
3735 |
|
3736 for (i = 0; i < row_width; i++) |
|
3737 { |
|
3738 if ((int)(*sp) >= num_trans) |
|
3739 *dp-- = 0xff; |
|
3740 else |
|
3741 *dp-- = trans[*sp]; |
|
3742 *dp-- = palette[*sp].blue; |
|
3743 *dp-- = palette[*sp].green; |
|
3744 *dp-- = palette[*sp].red; |
|
3745 sp--; |
|
3746 } |
|
3747 row_info->bit_depth = 8; |
|
3748 row_info->pixel_depth = 32; |
|
3749 row_info->rowbytes = row_width * 4; |
|
3750 row_info->color_type = 6; |
|
3751 row_info->channels = 4; |
|
3752 } |
|
3753 else |
|
3754 { |
|
3755 sp = row + (png_size_t)row_width - 1; |
|
3756 dp = row + (png_size_t)(row_width * 3) - 1; |
|
3757 |
|
3758 for (i = 0; i < row_width; i++) |
|
3759 { |
|
3760 *dp-- = palette[*sp].blue; |
|
3761 *dp-- = palette[*sp].green; |
|
3762 *dp-- = palette[*sp].red; |
|
3763 sp--; |
|
3764 } |
|
3765 |
|
3766 row_info->bit_depth = 8; |
|
3767 row_info->pixel_depth = 24; |
|
3768 row_info->rowbytes = row_width * 3; |
|
3769 row_info->color_type = 2; |
|
3770 row_info->channels = 3; |
|
3771 } |
|
3772 break; |
|
3773 } |
|
3774 } |
|
3775 } |
|
3776 } |
|
3777 |
|
3778 /* If the bit depth < 8, it is expanded to 8. Also, if the already |
|
3779 * expanded transparency value is supplied, an alpha channel is built. |
|
3780 */ |
|
3781 void /* PRIVATE */ |
|
3782 png_do_expand(png_row_infop row_info, png_bytep row, |
|
3783 png_color_16p trans_value) |
|
3784 { |
|
3785 int shift, value; |
|
3786 png_bytep sp, dp; |
|
3787 png_uint_32 i; |
|
3788 png_uint_32 row_width=row_info->width; |
|
3789 |
|
3790 png_debug(1, "in png_do_expand"); |
|
3791 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
3792 if (row != NULL && row_info != NULL) |
|
3793 #endif |
|
3794 { |
|
3795 if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
|
3796 { |
|
3797 png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0); |
|
3798 |
|
3799 if (row_info->bit_depth < 8) |
|
3800 { |
|
3801 switch (row_info->bit_depth) |
|
3802 { |
|
3803 case 1: |
|
3804 { |
|
3805 gray = (png_uint_16)((gray&0x01)*0xff); |
|
3806 sp = row + (png_size_t)((row_width - 1) >> 3); |
|
3807 dp = row + (png_size_t)row_width - 1; |
|
3808 shift = 7 - (int)((row_width + 7) & 0x07); |
|
3809 for (i = 0; i < row_width; i++) |
|
3810 { |
|
3811 if ((*sp >> shift) & 0x01) |
|
3812 *dp = 0xff; |
|
3813 else |
|
3814 *dp = 0; |
|
3815 if (shift == 7) |
|
3816 { |
|
3817 shift = 0; |
|
3818 sp--; |
|
3819 } |
|
3820 else |
|
3821 shift++; |
|
3822 |
|
3823 dp--; |
|
3824 } |
|
3825 break; |
|
3826 } |
|
3827 |
|
3828 case 2: |
|
3829 { |
|
3830 gray = (png_uint_16)((gray&0x03)*0x55); |
|
3831 sp = row + (png_size_t)((row_width - 1) >> 2); |
|
3832 dp = row + (png_size_t)row_width - 1; |
|
3833 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
|
3834 for (i = 0; i < row_width; i++) |
|
3835 { |
|
3836 value = (*sp >> shift) & 0x03; |
|
3837 *dp = (png_byte)(value | (value << 2) | (value << 4) | |
|
3838 (value << 6)); |
|
3839 if (shift == 6) |
|
3840 { |
|
3841 shift = 0; |
|
3842 sp--; |
|
3843 } |
|
3844 else |
|
3845 shift += 2; |
|
3846 |
|
3847 dp--; |
|
3848 } |
|
3849 break; |
|
3850 } |
|
3851 |
|
3852 case 4: |
|
3853 { |
|
3854 gray = (png_uint_16)((gray&0x0f)*0x11); |
|
3855 sp = row + (png_size_t)((row_width - 1) >> 1); |
|
3856 dp = row + (png_size_t)row_width - 1; |
|
3857 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); |
|
3858 for (i = 0; i < row_width; i++) |
|
3859 { |
|
3860 value = (*sp >> shift) & 0x0f; |
|
3861 *dp = (png_byte)(value | (value << 4)); |
|
3862 if (shift == 4) |
|
3863 { |
|
3864 shift = 0; |
|
3865 sp--; |
|
3866 } |
|
3867 else |
|
3868 shift = 4; |
|
3869 |
|
3870 dp--; |
|
3871 } |
|
3872 break; |
|
3873 } |
|
3874 } |
|
3875 |
|
3876 row_info->bit_depth = 8; |
|
3877 row_info->pixel_depth = 8; |
|
3878 row_info->rowbytes = row_width; |
|
3879 } |
|
3880 |
|
3881 if (trans_value != NULL) |
|
3882 { |
|
3883 if (row_info->bit_depth == 8) |
|
3884 { |
|
3885 gray = gray & 0xff; |
|
3886 sp = row + (png_size_t)row_width - 1; |
|
3887 dp = row + (png_size_t)(row_width << 1) - 1; |
|
3888 for (i = 0; i < row_width; i++) |
|
3889 { |
|
3890 if (*sp == gray) |
|
3891 *dp-- = 0; |
|
3892 else |
|
3893 *dp-- = 0xff; |
|
3894 *dp-- = *sp--; |
|
3895 } |
|
3896 } |
|
3897 |
|
3898 else if (row_info->bit_depth == 16) |
|
3899 { |
|
3900 png_byte gray_high = (gray >> 8) & 0xff; |
|
3901 png_byte gray_low = gray & 0xff; |
|
3902 sp = row + row_info->rowbytes - 1; |
|
3903 dp = row + (row_info->rowbytes << 1) - 1; |
|
3904 for (i = 0; i < row_width; i++) |
|
3905 { |
|
3906 if (*(sp - 1) == gray_high && *(sp) == gray_low) |
|
3907 { |
|
3908 *dp-- = 0; |
|
3909 *dp-- = 0; |
|
3910 } |
|
3911 else |
|
3912 { |
|
3913 *dp-- = 0xff; |
|
3914 *dp-- = 0xff; |
|
3915 } |
|
3916 *dp-- = *sp--; |
|
3917 *dp-- = *sp--; |
|
3918 } |
|
3919 } |
|
3920 |
|
3921 row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; |
|
3922 row_info->channels = 2; |
|
3923 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); |
|
3924 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, |
|
3925 row_width); |
|
3926 } |
|
3927 } |
|
3928 else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value) |
|
3929 { |
|
3930 if (row_info->bit_depth == 8) |
|
3931 { |
|
3932 png_byte red = trans_value->red & 0xff; |
|
3933 png_byte green = trans_value->green & 0xff; |
|
3934 png_byte blue = trans_value->blue & 0xff; |
|
3935 sp = row + (png_size_t)row_info->rowbytes - 1; |
|
3936 dp = row + (png_size_t)(row_width << 2) - 1; |
|
3937 for (i = 0; i < row_width; i++) |
|
3938 { |
|
3939 if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue) |
|
3940 *dp-- = 0; |
|
3941 else |
|
3942 *dp-- = 0xff; |
|
3943 *dp-- = *sp--; |
|
3944 *dp-- = *sp--; |
|
3945 *dp-- = *sp--; |
|
3946 } |
|
3947 } |
|
3948 else if (row_info->bit_depth == 16) |
|
3949 { |
|
3950 png_byte red_high = (trans_value->red >> 8) & 0xff; |
|
3951 png_byte green_high = (trans_value->green >> 8) & 0xff; |
|
3952 png_byte blue_high = (trans_value->blue >> 8) & 0xff; |
|
3953 png_byte red_low = trans_value->red & 0xff; |
|
3954 png_byte green_low = trans_value->green & 0xff; |
|
3955 png_byte blue_low = trans_value->blue & 0xff; |
|
3956 sp = row + row_info->rowbytes - 1; |
|
3957 dp = row + (png_size_t)(row_width << 3) - 1; |
|
3958 for (i = 0; i < row_width; i++) |
|
3959 { |
|
3960 if (*(sp - 5) == red_high && |
|
3961 *(sp - 4) == red_low && |
|
3962 *(sp - 3) == green_high && |
|
3963 *(sp - 2) == green_low && |
|
3964 *(sp - 1) == blue_high && |
|
3965 *(sp ) == blue_low) |
|
3966 { |
|
3967 *dp-- = 0; |
|
3968 *dp-- = 0; |
|
3969 } |
|
3970 else |
|
3971 { |
|
3972 *dp-- = 0xff; |
|
3973 *dp-- = 0xff; |
|
3974 } |
|
3975 *dp-- = *sp--; |
|
3976 *dp-- = *sp--; |
|
3977 *dp-- = *sp--; |
|
3978 *dp-- = *sp--; |
|
3979 *dp-- = *sp--; |
|
3980 *dp-- = *sp--; |
|
3981 } |
|
3982 } |
|
3983 row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
|
3984 row_info->channels = 4; |
|
3985 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); |
|
3986 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
3987 } |
|
3988 } |
|
3989 } |
|
3990 #endif |
|
3991 |
|
3992 #if defined(PNG_READ_DITHER_SUPPORTED) |
|
3993 void /* PRIVATE */ |
|
3994 png_do_dither(png_row_infop row_info, png_bytep row, |
|
3995 png_bytep palette_lookup, png_bytep dither_lookup) |
|
3996 { |
|
3997 png_bytep sp, dp; |
|
3998 png_uint_32 i; |
|
3999 png_uint_32 row_width=row_info->width; |
|
4000 |
|
4001 png_debug(1, "in png_do_dither"); |
|
4002 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
4003 if (row != NULL && row_info != NULL) |
|
4004 #endif |
|
4005 { |
|
4006 if (row_info->color_type == PNG_COLOR_TYPE_RGB && |
|
4007 palette_lookup && row_info->bit_depth == 8) |
|
4008 { |
|
4009 int r, g, b, p; |
|
4010 sp = row; |
|
4011 dp = row; |
|
4012 for (i = 0; i < row_width; i++) |
|
4013 { |
|
4014 r = *sp++; |
|
4015 g = *sp++; |
|
4016 b = *sp++; |
|
4017 |
|
4018 /* This looks real messy, but the compiler will reduce |
|
4019 * it down to a reasonable formula. For example, with |
|
4020 * 5 bits per color, we get: |
|
4021 * p = (((r >> 3) & 0x1f) << 10) | |
|
4022 * (((g >> 3) & 0x1f) << 5) | |
|
4023 * ((b >> 3) & 0x1f); |
|
4024 */ |
|
4025 p = (((r >> (8 - PNG_DITHER_RED_BITS)) & |
|
4026 ((1 << PNG_DITHER_RED_BITS) - 1)) << |
|
4027 (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | |
|
4028 (((g >> (8 - PNG_DITHER_GREEN_BITS)) & |
|
4029 ((1 << PNG_DITHER_GREEN_BITS) - 1)) << |
|
4030 (PNG_DITHER_BLUE_BITS)) | |
|
4031 ((b >> (8 - PNG_DITHER_BLUE_BITS)) & |
|
4032 ((1 << PNG_DITHER_BLUE_BITS) - 1)); |
|
4033 |
|
4034 *dp++ = palette_lookup[p]; |
|
4035 } |
|
4036 row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
|
4037 row_info->channels = 1; |
|
4038 row_info->pixel_depth = row_info->bit_depth; |
|
4039 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
4040 } |
|
4041 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && |
|
4042 palette_lookup != NULL && row_info->bit_depth == 8) |
|
4043 { |
|
4044 int r, g, b, p; |
|
4045 sp = row; |
|
4046 dp = row; |
|
4047 for (i = 0; i < row_width; i++) |
|
4048 { |
|
4049 r = *sp++; |
|
4050 g = *sp++; |
|
4051 b = *sp++; |
|
4052 sp++; |
|
4053 |
|
4054 p = (((r >> (8 - PNG_DITHER_RED_BITS)) & |
|
4055 ((1 << PNG_DITHER_RED_BITS) - 1)) << |
|
4056 (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | |
|
4057 (((g >> (8 - PNG_DITHER_GREEN_BITS)) & |
|
4058 ((1 << PNG_DITHER_GREEN_BITS) - 1)) << |
|
4059 (PNG_DITHER_BLUE_BITS)) | |
|
4060 ((b >> (8 - PNG_DITHER_BLUE_BITS)) & |
|
4061 ((1 << PNG_DITHER_BLUE_BITS) - 1)); |
|
4062 |
|
4063 *dp++ = palette_lookup[p]; |
|
4064 } |
|
4065 row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
|
4066 row_info->channels = 1; |
|
4067 row_info->pixel_depth = row_info->bit_depth; |
|
4068 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
4069 } |
|
4070 else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && |
|
4071 dither_lookup && row_info->bit_depth == 8) |
|
4072 { |
|
4073 sp = row; |
|
4074 for (i = 0; i < row_width; i++, sp++) |
|
4075 { |
|
4076 *sp = dither_lookup[*sp]; |
|
4077 } |
|
4078 } |
|
4079 } |
|
4080 } |
|
4081 #endif |
|
4082 |
|
4083 #ifdef PNG_FLOATING_POINT_SUPPORTED |
|
4084 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
4085 static PNG_CONST int png_gamma_shift[] = |
|
4086 {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00}; |
|
4087 |
|
4088 /* We build the 8- or 16-bit gamma tables here. Note that for 16-bit |
|
4089 * tables, we don't make a full table if we are reducing to 8-bit in |
|
4090 * the future. Note also how the gamma_16 tables are segmented so that |
|
4091 * we don't need to allocate > 64K chunks for a full 16-bit table. |
|
4092 */ |
|
4093 void /* PRIVATE */ |
|
4094 png_build_gamma_table(png_structp png_ptr) |
|
4095 { |
|
4096 png_debug(1, "in png_build_gamma_table"); |
|
4097 |
|
4098 if (png_ptr->bit_depth <= 8) |
|
4099 { |
|
4100 int i; |
|
4101 double g; |
|
4102 |
|
4103 if (png_ptr->screen_gamma > .000001) |
|
4104 g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
|
4105 |
|
4106 else |
|
4107 g = 1.0; |
|
4108 |
|
4109 png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr, |
|
4110 (png_uint_32)256); |
|
4111 |
|
4112 for (i = 0; i < 256; i++) |
|
4113 { |
|
4114 png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0, |
|
4115 g) * 255.0 + .5); |
|
4116 } |
|
4117 |
|
4118 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ |
|
4119 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
4120 if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY)) |
|
4121 { |
|
4122 |
|
4123 g = 1.0 / (png_ptr->gamma); |
|
4124 |
|
4125 png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr, |
|
4126 (png_uint_32)256); |
|
4127 |
|
4128 for (i = 0; i < 256; i++) |
|
4129 { |
|
4130 png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0, |
|
4131 g) * 255.0 + .5); |
|
4132 } |
|
4133 |
|
4134 |
|
4135 png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr, |
|
4136 (png_uint_32)256); |
|
4137 |
|
4138 if (png_ptr->screen_gamma > 0.000001) |
|
4139 g = 1.0 / png_ptr->screen_gamma; |
|
4140 |
|
4141 else |
|
4142 g = png_ptr->gamma; /* Probably doing rgb_to_gray */ |
|
4143 |
|
4144 for (i = 0; i < 256; i++) |
|
4145 { |
|
4146 png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0, |
|
4147 g) * 255.0 + .5); |
|
4148 |
|
4149 } |
|
4150 } |
|
4151 #endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ |
|
4152 } |
|
4153 else |
|
4154 { |
|
4155 double g; |
|
4156 int i, j, shift, num; |
|
4157 int sig_bit; |
|
4158 png_uint_32 ig; |
|
4159 |
|
4160 if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) |
|
4161 { |
|
4162 sig_bit = (int)png_ptr->sig_bit.red; |
|
4163 |
|
4164 if ((int)png_ptr->sig_bit.green > sig_bit) |
|
4165 sig_bit = png_ptr->sig_bit.green; |
|
4166 |
|
4167 if ((int)png_ptr->sig_bit.blue > sig_bit) |
|
4168 sig_bit = png_ptr->sig_bit.blue; |
|
4169 } |
|
4170 else |
|
4171 { |
|
4172 sig_bit = (int)png_ptr->sig_bit.gray; |
|
4173 } |
|
4174 |
|
4175 if (sig_bit > 0) |
|
4176 shift = 16 - sig_bit; |
|
4177 |
|
4178 else |
|
4179 shift = 0; |
|
4180 |
|
4181 if (png_ptr->transformations & PNG_16_TO_8) |
|
4182 { |
|
4183 if (shift < (16 - PNG_MAX_GAMMA_8)) |
|
4184 shift = (16 - PNG_MAX_GAMMA_8); |
|
4185 } |
|
4186 |
|
4187 if (shift > 8) |
|
4188 shift = 8; |
|
4189 |
|
4190 if (shift < 0) |
|
4191 shift = 0; |
|
4192 |
|
4193 png_ptr->gamma_shift = (png_byte)shift; |
|
4194 |
|
4195 num = (1 << (8 - shift)); |
|
4196 |
|
4197 if (png_ptr->screen_gamma > .000001) |
|
4198 g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
|
4199 else |
|
4200 g = 1.0; |
|
4201 |
|
4202 png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr, |
|
4203 (png_uint_32)(num * png_sizeof(png_uint_16p))); |
|
4204 png_memset(png_ptr->gamma_16_table, 0, num * png_sizeof(png_uint_16p)); |
|
4205 |
|
4206 if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND)) |
|
4207 { |
|
4208 double fin, fout; |
|
4209 png_uint_32 last, max; |
|
4210 |
|
4211 for (i = 0; i < num; i++) |
|
4212 { |
|
4213 png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, |
|
4214 (png_uint_32)(256 * png_sizeof(png_uint_16))); |
|
4215 } |
|
4216 |
|
4217 g = 1.0 / g; |
|
4218 last = 0; |
|
4219 for (i = 0; i < 256; i++) |
|
4220 { |
|
4221 fout = ((double)i + 0.5) / 256.0; |
|
4222 fin = pow(fout, g); |
|
4223 max = (png_uint_32)(fin * (double)((png_uint_32)num << 8)); |
|
4224 while (last <= max) |
|
4225 { |
|
4226 png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] |
|
4227 [(int)(last >> (8 - shift))] = (png_uint_16)( |
|
4228 (png_uint_16)i | ((png_uint_16)i << 8)); |
|
4229 last++; |
|
4230 } |
|
4231 } |
|
4232 while (last < ((png_uint_32)num << 8)) |
|
4233 { |
|
4234 png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] |
|
4235 [(int)(last >> (8 - shift))] = (png_uint_16)65535L; |
|
4236 last++; |
|
4237 } |
|
4238 } |
|
4239 else |
|
4240 { |
|
4241 for (i = 0; i < num; i++) |
|
4242 { |
|
4243 png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, |
|
4244 (png_uint_32)(256 * png_sizeof(png_uint_16))); |
|
4245 |
|
4246 ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4); |
|
4247 |
|
4248 for (j = 0; j < 256; j++) |
|
4249 { |
|
4250 png_ptr->gamma_16_table[i][j] = |
|
4251 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
|
4252 65535.0, g) * 65535.0 + .5); |
|
4253 } |
|
4254 } |
|
4255 } |
|
4256 |
|
4257 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ |
|
4258 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
4259 if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY)) |
|
4260 { |
|
4261 |
|
4262 g = 1.0 / (png_ptr->gamma); |
|
4263 |
|
4264 png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr, |
|
4265 (png_uint_32)(num * png_sizeof(png_uint_16p ))); |
|
4266 png_memset(png_ptr->gamma_16_to_1, 0, num * png_sizeof(png_uint_16p)); |
|
4267 |
|
4268 for (i = 0; i < num; i++) |
|
4269 { |
|
4270 png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr, |
|
4271 (png_uint_32)(256 * png_sizeof(png_uint_16))); |
|
4272 |
|
4273 ig = (((png_uint_32)i * |
|
4274 (png_uint_32)png_gamma_shift[shift]) >> 4); |
|
4275 for (j = 0; j < 256; j++) |
|
4276 { |
|
4277 png_ptr->gamma_16_to_1[i][j] = |
|
4278 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
|
4279 65535.0, g) * 65535.0 + .5); |
|
4280 } |
|
4281 } |
|
4282 |
|
4283 if (png_ptr->screen_gamma > 0.000001) |
|
4284 g = 1.0 / png_ptr->screen_gamma; |
|
4285 |
|
4286 else |
|
4287 g = png_ptr->gamma; /* Probably doing rgb_to_gray */ |
|
4288 |
|
4289 png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr, |
|
4290 (png_uint_32)(num * png_sizeof(png_uint_16p))); |
|
4291 png_memset(png_ptr->gamma_16_from_1, 0, |
|
4292 num * png_sizeof(png_uint_16p)); |
|
4293 |
|
4294 for (i = 0; i < num; i++) |
|
4295 { |
|
4296 png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr, |
|
4297 (png_uint_32)(256 * png_sizeof(png_uint_16))); |
|
4298 |
|
4299 ig = (((png_uint_32)i * |
|
4300 (png_uint_32)png_gamma_shift[shift]) >> 4); |
|
4301 |
|
4302 for (j = 0; j < 256; j++) |
|
4303 { |
|
4304 png_ptr->gamma_16_from_1[i][j] = |
|
4305 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
|
4306 65535.0, g) * 65535.0 + .5); |
|
4307 } |
|
4308 } |
|
4309 } |
|
4310 #endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ |
|
4311 } |
|
4312 } |
|
4313 #endif |
|
4314 /* To do: install integer version of png_build_gamma_table here */ |
|
4315 #endif |
|
4316 |
|
4317 #if defined(PNG_MNG_FEATURES_SUPPORTED) |
|
4318 /* Undoes intrapixel differencing */ |
|
4319 void /* PRIVATE */ |
|
4320 png_do_read_intrapixel(png_row_infop row_info, png_bytep row) |
|
4321 { |
|
4322 png_debug(1, "in png_do_read_intrapixel"); |
|
4323 if ( |
|
4324 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
4325 row != NULL && row_info != NULL && |
|
4326 #endif |
|
4327 (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
|
4328 { |
|
4329 int bytes_per_pixel; |
|
4330 png_uint_32 row_width = row_info->width; |
|
4331 if (row_info->bit_depth == 8) |
|
4332 { |
|
4333 png_bytep rp; |
|
4334 png_uint_32 i; |
|
4335 |
|
4336 if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
4337 bytes_per_pixel = 3; |
|
4338 |
|
4339 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
4340 bytes_per_pixel = 4; |
|
4341 |
|
4342 else |
|
4343 return; |
|
4344 |
|
4345 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) |
|
4346 { |
|
4347 *(rp) = (png_byte)((256 + *rp + *(rp+1))&0xff); |
|
4348 *(rp+2) = (png_byte)((256 + *(rp+2) + *(rp+1))&0xff); |
|
4349 } |
|
4350 } |
|
4351 else if (row_info->bit_depth == 16) |
|
4352 { |
|
4353 png_bytep rp; |
|
4354 png_uint_32 i; |
|
4355 |
|
4356 if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
4357 bytes_per_pixel = 6; |
|
4358 |
|
4359 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
4360 bytes_per_pixel = 8; |
|
4361 |
|
4362 else |
|
4363 return; |
|
4364 |
|
4365 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) |
|
4366 { |
|
4367 png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); |
|
4368 png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); |
|
4369 png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); |
|
4370 png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL); |
|
4371 png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL); |
|
4372 *(rp ) = (png_byte)((red >> 8) & 0xff); |
|
4373 *(rp+1) = (png_byte)(red & 0xff); |
|
4374 *(rp+4) = (png_byte)((blue >> 8) & 0xff); |
|
4375 *(rp+5) = (png_byte)(blue & 0xff); |
|
4376 } |
|
4377 } |
|
4378 } |
|
4379 } |
|
4380 #endif /* PNG_MNG_FEATURES_SUPPORTED */ |
|
4381 #endif /* PNG_READ_SUPPORTED */ |