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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 1.2.30 [August 15, 2008] |
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5 * For conditions of distribution and use, see copyright notice in png.h |
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6 * Copyright (c) 1998-2008 Glenn Randers-Pehrson |
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7 * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
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8 * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
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9 * |
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10 * This file contains functions optionally called by an application |
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11 * in order to tell libpng how to handle data when reading a PNG. |
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12 * Transformations that are used in both reading and writing are |
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13 * in pngtrans.c. |
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14 */ |
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15 |
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16 #define PNG_INTERNAL |
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17 #include "png.h" |
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18 #if defined(PNG_READ_SUPPORTED) |
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19 |
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20 /* Set the action on getting a CRC error for an ancillary or critical chunk. */ |
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21 void PNGAPI |
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22 png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) |
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23 { |
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24 png_debug(1, "in png_set_crc_action\n"); |
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25 /* Tell libpng how we react to CRC errors in critical chunks */ |
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26 if (png_ptr == NULL) return; |
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27 switch (crit_action) |
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28 { |
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29 case PNG_CRC_NO_CHANGE: /* leave setting as is */ |
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30 break; |
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31 case PNG_CRC_WARN_USE: /* warn/use data */ |
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32 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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33 png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; |
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34 break; |
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35 case PNG_CRC_QUIET_USE: /* quiet/use data */ |
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36 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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37 png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | |
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38 PNG_FLAG_CRC_CRITICAL_IGNORE; |
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39 break; |
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40 case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */ |
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41 png_warning(png_ptr, |
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42 "Can't discard critical data on CRC error."); |
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43 case PNG_CRC_ERROR_QUIT: /* error/quit */ |
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44 case PNG_CRC_DEFAULT: |
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45 default: |
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46 png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; |
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47 break; |
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48 } |
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49 |
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50 switch (ancil_action) |
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51 { |
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52 case PNG_CRC_NO_CHANGE: /* leave setting as is */ |
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53 break; |
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54 case PNG_CRC_WARN_USE: /* warn/use data */ |
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55 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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56 png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; |
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57 break; |
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58 case PNG_CRC_QUIET_USE: /* quiet/use data */ |
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59 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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60 png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | |
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61 PNG_FLAG_CRC_ANCILLARY_NOWARN; |
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62 break; |
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63 case PNG_CRC_ERROR_QUIT: /* error/quit */ |
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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_NOWARN; |
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66 break; |
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67 case PNG_CRC_WARN_DISCARD: /* warn/discard data */ |
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68 case PNG_CRC_DEFAULT: |
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69 default: |
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70 png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; |
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71 break; |
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72 } |
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73 } |
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74 |
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75 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ |
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76 defined(PNG_FLOATING_POINT_SUPPORTED) |
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77 /* handle alpha and tRNS via a background color */ |
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78 void PNGAPI |
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79 png_set_background(png_structp png_ptr, |
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80 png_color_16p background_color, int background_gamma_code, |
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81 int need_expand, double background_gamma) |
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82 { |
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83 png_debug(1, "in png_set_background\n"); |
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84 if (png_ptr == NULL) return; |
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85 if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) |
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86 { |
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87 png_warning(png_ptr, "Application must supply a known background gamma"); |
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88 return; |
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89 } |
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90 |
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91 png_ptr->transformations |= PNG_BACKGROUND; |
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92 png_memcpy(&(png_ptr->background), background_color, |
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93 png_sizeof(png_color_16)); |
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94 png_ptr->background_gamma = (float)background_gamma; |
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95 png_ptr->background_gamma_type = (png_byte)(background_gamma_code); |
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96 png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0); |
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97 } |
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98 #endif |
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99 |
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100 #if defined(PNG_READ_16_TO_8_SUPPORTED) |
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101 /* strip 16 bit depth files to 8 bit depth */ |
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102 void PNGAPI |
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103 png_set_strip_16(png_structp png_ptr) |
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104 { |
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105 png_debug(1, "in png_set_strip_16\n"); |
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106 if (png_ptr == NULL) return; |
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107 png_ptr->transformations |= PNG_16_TO_8; |
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108 } |
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109 #endif |
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110 |
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111 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
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112 void PNGAPI |
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113 png_set_strip_alpha(png_structp png_ptr) |
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114 { |
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115 png_debug(1, "in png_set_strip_alpha\n"); |
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116 if (png_ptr == NULL) return; |
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117 png_ptr->flags |= PNG_FLAG_STRIP_ALPHA; |
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118 } |
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119 #endif |
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120 |
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121 #if defined(PNG_READ_DITHER_SUPPORTED) |
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122 /* Dither file to 8 bit. Supply a palette, the current number |
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123 * of elements in the palette, the maximum number of elements |
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124 * allowed, and a histogram if possible. If the current number |
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125 * of colors is greater then the maximum number, the palette will be |
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126 * modified to fit in the maximum number. "full_dither" indicates |
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127 * whether we need a dithering cube set up for RGB images, or if we |
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128 * simply are reducing the number of colors in a paletted image. |
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129 */ |
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130 |
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131 typedef struct png_dsort_struct |
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132 { |
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133 struct png_dsort_struct FAR * next; |
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134 png_byte left; |
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135 png_byte right; |
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136 } png_dsort; |
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137 typedef png_dsort FAR * png_dsortp; |
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138 typedef png_dsort FAR * FAR * png_dsortpp; |
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139 |
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140 void PNGAPI |
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141 png_set_dither(png_structp png_ptr, png_colorp palette, |
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142 int num_palette, int maximum_colors, png_uint_16p histogram, |
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143 int full_dither) |
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144 { |
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145 png_debug(1, "in png_set_dither\n"); |
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146 if (png_ptr == NULL) return; |
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147 png_ptr->transformations |= PNG_DITHER; |
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148 |
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149 if (!full_dither) |
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150 { |
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151 int i; |
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152 |
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153 png_ptr->dither_index = (png_bytep)png_malloc(png_ptr, |
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154 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
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155 for (i = 0; i < num_palette; i++) |
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156 png_ptr->dither_index[i] = (png_byte)i; |
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157 } |
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158 |
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159 if (num_palette > maximum_colors) |
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160 { |
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161 if (histogram != NULL) |
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162 { |
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163 /* This is easy enough, just throw out the least used colors. |
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164 Perhaps not the best solution, but good enough. */ |
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165 |
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166 int i; |
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167 |
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168 /* initialize an array to sort colors */ |
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169 png_ptr->dither_sort = (png_bytep)png_malloc(png_ptr, |
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170 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
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171 |
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172 /* initialize the dither_sort array */ |
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173 for (i = 0; i < num_palette; i++) |
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174 png_ptr->dither_sort[i] = (png_byte)i; |
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175 |
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176 /* Find the least used palette entries by starting a |
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177 bubble sort, and running it until we have sorted |
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178 out enough colors. Note that we don't care about |
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179 sorting all the colors, just finding which are |
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180 least used. */ |
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181 |
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182 for (i = num_palette - 1; i >= maximum_colors; i--) |
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183 { |
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184 int done; /* to stop early if the list is pre-sorted */ |
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185 int j; |
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186 |
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187 done = 1; |
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188 for (j = 0; j < i; j++) |
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189 { |
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190 if (histogram[png_ptr->dither_sort[j]] |
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191 < histogram[png_ptr->dither_sort[j + 1]]) |
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192 { |
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193 png_byte t; |
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194 |
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195 t = png_ptr->dither_sort[j]; |
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196 png_ptr->dither_sort[j] = png_ptr->dither_sort[j + 1]; |
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197 png_ptr->dither_sort[j + 1] = t; |
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198 done = 0; |
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199 } |
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200 } |
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201 if (done) |
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202 break; |
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203 } |
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204 |
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205 /* swap the palette around, and set up a table, if necessary */ |
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206 if (full_dither) |
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207 { |
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208 int j = num_palette; |
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209 |
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210 /* put all the useful colors within the max, but don't |
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211 move the others */ |
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212 for (i = 0; i < maximum_colors; i++) |
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213 { |
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214 if ((int)png_ptr->dither_sort[i] >= maximum_colors) |
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215 { |
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216 do |
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217 j--; |
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218 while ((int)png_ptr->dither_sort[j] >= maximum_colors); |
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219 palette[i] = palette[j]; |
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220 } |
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221 } |
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222 } |
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223 else |
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224 { |
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225 int j = num_palette; |
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226 |
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227 /* move all the used colors inside the max limit, and |
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228 develop a translation table */ |
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229 for (i = 0; i < maximum_colors; i++) |
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230 { |
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231 /* only move the colors we need to */ |
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232 if ((int)png_ptr->dither_sort[i] >= maximum_colors) |
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233 { |
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234 png_color tmp_color; |
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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 |
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240 tmp_color = palette[j]; |
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241 palette[j] = palette[i]; |
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242 palette[i] = tmp_color; |
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243 /* indicate where the color went */ |
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244 png_ptr->dither_index[j] = (png_byte)i; |
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245 png_ptr->dither_index[i] = (png_byte)j; |
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246 } |
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247 } |
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248 |
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249 /* find closest color for those colors we are not using */ |
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250 for (i = 0; i < num_palette; i++) |
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251 { |
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252 if ((int)png_ptr->dither_index[i] >= maximum_colors) |
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253 { |
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254 int min_d, k, min_k, d_index; |
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255 |
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256 /* find the closest color to one we threw out */ |
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257 d_index = png_ptr->dither_index[i]; |
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258 min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); |
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259 for (k = 1, min_k = 0; k < maximum_colors; k++) |
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260 { |
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261 int d; |
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262 |
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263 d = PNG_COLOR_DIST(palette[d_index], palette[k]); |
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264 |
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265 if (d < min_d) |
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266 { |
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267 min_d = d; |
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268 min_k = k; |
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269 } |
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270 } |
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271 /* point to closest color */ |
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272 png_ptr->dither_index[i] = (png_byte)min_k; |
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273 } |
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274 } |
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275 } |
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276 png_free(png_ptr, png_ptr->dither_sort); |
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277 png_ptr->dither_sort = NULL; |
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278 } |
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279 else |
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280 { |
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281 /* This is much harder to do simply (and quickly). Perhaps |
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282 we need to go through a median cut routine, but those |
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283 don't always behave themselves with only a few colors |
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284 as input. So we will just find the closest two colors, |
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285 and throw out one of them (chosen somewhat randomly). |
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286 [We don't understand this at all, so if someone wants to |
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287 work on improving it, be our guest - AED, GRP] |
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288 */ |
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289 int i; |
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290 int max_d; |
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291 int num_new_palette; |
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292 png_dsortp t; |
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293 png_dsortpp hash; |
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294 |
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295 t = NULL; |
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296 |
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297 /* initialize palette index arrays */ |
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298 png_ptr->index_to_palette = (png_bytep)png_malloc(png_ptr, |
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299 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
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300 png_ptr->palette_to_index = (png_bytep)png_malloc(png_ptr, |
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301 (png_uint_32)(num_palette * png_sizeof(png_byte))); |
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302 |
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303 /* initialize the sort array */ |
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304 for (i = 0; i < num_palette; i++) |
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305 { |
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306 png_ptr->index_to_palette[i] = (png_byte)i; |
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307 png_ptr->palette_to_index[i] = (png_byte)i; |
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308 } |
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309 |
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310 hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 * |
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311 png_sizeof(png_dsortp))); |
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312 for (i = 0; i < 769; i++) |
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313 hash[i] = NULL; |
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314 /* png_memset(hash, 0, 769 * png_sizeof(png_dsortp)); */ |
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315 |
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316 num_new_palette = num_palette; |
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317 |
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318 /* initial wild guess at how far apart the farthest pixel |
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319 pair we will be eliminating will be. Larger |
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320 numbers mean more areas will be allocated, Smaller |
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321 numbers run the risk of not saving enough data, and |
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322 having to do this all over again. |
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323 |
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324 I have not done extensive checking on this number. |
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325 */ |
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326 max_d = 96; |
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327 |
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328 while (num_new_palette > maximum_colors) |
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329 { |
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330 for (i = 0; i < num_new_palette - 1; i++) |
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331 { |
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332 int j; |
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333 |
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334 for (j = i + 1; j < num_new_palette; j++) |
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335 { |
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336 int d; |
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337 |
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338 d = PNG_COLOR_DIST(palette[i], palette[j]); |
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339 |
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340 if (d <= max_d) |
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341 { |
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342 |
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343 t = (png_dsortp)png_malloc_warn(png_ptr, |
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344 (png_uint_32)(png_sizeof(png_dsort))); |
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345 if (t == NULL) |
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346 break; |
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347 t->next = hash[d]; |
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348 t->left = (png_byte)i; |
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349 t->right = (png_byte)j; |
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350 hash[d] = t; |
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351 } |
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352 } |
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353 if (t == NULL) |
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354 break; |
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355 } |
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356 |
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357 if (t != NULL) |
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358 for (i = 0; i <= max_d; i++) |
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359 { |
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360 if (hash[i] != NULL) |
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361 { |
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362 png_dsortp p; |
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363 |
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364 for (p = hash[i]; p; p = p->next) |
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365 { |
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366 if ((int)png_ptr->index_to_palette[p->left] |
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367 < num_new_palette && |
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368 (int)png_ptr->index_to_palette[p->right] |
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369 < num_new_palette) |
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370 { |
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371 int j, next_j; |
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372 |
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373 if (num_new_palette & 0x01) |
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374 { |
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375 j = p->left; |
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376 next_j = p->right; |
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377 } |
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378 else |
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379 { |
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380 j = p->right; |
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381 next_j = p->left; |
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382 } |
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383 |
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384 num_new_palette--; |
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385 palette[png_ptr->index_to_palette[j]] |
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386 = palette[num_new_palette]; |
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387 if (!full_dither) |
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388 { |
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389 int k; |
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390 |
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391 for (k = 0; k < num_palette; k++) |
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392 { |
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393 if (png_ptr->dither_index[k] == |
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394 png_ptr->index_to_palette[j]) |
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395 png_ptr->dither_index[k] = |
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396 png_ptr->index_to_palette[next_j]; |
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397 if ((int)png_ptr->dither_index[k] == |
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398 num_new_palette) |
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399 png_ptr->dither_index[k] = |
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400 png_ptr->index_to_palette[j]; |
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401 } |
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402 } |
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403 |
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404 png_ptr->index_to_palette[png_ptr->palette_to_index |
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405 [num_new_palette]] = png_ptr->index_to_palette[j]; |
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406 png_ptr->palette_to_index[png_ptr->index_to_palette[j]] |
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407 = png_ptr->palette_to_index[num_new_palette]; |
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408 |
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409 png_ptr->index_to_palette[j] = (png_byte)num_new_palette; |
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410 png_ptr->palette_to_index[num_new_palette] = (png_byte)j; |
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411 } |
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412 if (num_new_palette <= maximum_colors) |
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413 break; |
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414 } |
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415 if (num_new_palette <= maximum_colors) |
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416 break; |
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417 } |
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418 } |
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419 |
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420 for (i = 0; i < 769; i++) |
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421 { |
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422 if (hash[i] != NULL) |
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423 { |
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424 png_dsortp p = hash[i]; |
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425 while (p) |
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426 { |
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427 t = p->next; |
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428 png_free(png_ptr, p); |
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429 p = t; |
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430 } |
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431 } |
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432 hash[i] = 0; |
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433 } |
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434 max_d += 96; |
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435 } |
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436 png_free(png_ptr, hash); |
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437 png_free(png_ptr, png_ptr->palette_to_index); |
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438 png_free(png_ptr, png_ptr->index_to_palette); |
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439 png_ptr->palette_to_index = NULL; |
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440 png_ptr->index_to_palette = NULL; |
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441 } |
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442 num_palette = maximum_colors; |
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443 } |
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444 if (png_ptr->palette == NULL) |
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445 { |
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446 png_ptr->palette = palette; |
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447 } |
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448 png_ptr->num_palette = (png_uint_16)num_palette; |
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449 |
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450 if (full_dither) |
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451 { |
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452 int i; |
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453 png_bytep distance; |
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454 int total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS + |
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455 PNG_DITHER_BLUE_BITS; |
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456 int num_red = (1 << PNG_DITHER_RED_BITS); |
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457 int num_green = (1 << PNG_DITHER_GREEN_BITS); |
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458 int num_blue = (1 << PNG_DITHER_BLUE_BITS); |
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459 png_size_t num_entries = ((png_size_t)1 << total_bits); |
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460 |
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461 png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr, |
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462 (png_uint_32)(num_entries * png_sizeof(png_byte))); |
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463 |
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464 png_memset(png_ptr->palette_lookup, 0, num_entries * |
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465 png_sizeof(png_byte)); |
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466 |
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467 distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * |
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468 png_sizeof(png_byte))); |
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469 |
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470 png_memset(distance, 0xff, num_entries * png_sizeof(png_byte)); |
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471 |
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472 for (i = 0; i < num_palette; i++) |
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473 { |
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474 int ir, ig, ib; |
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475 int r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS)); |
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476 int g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS)); |
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477 int b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS)); |
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478 |
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479 for (ir = 0; ir < num_red; ir++) |
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480 { |
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481 /* int dr = abs(ir - r); */ |
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482 int dr = ((ir > r) ? ir - r : r - ir); |
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483 int index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS)); |
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484 |
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485 for (ig = 0; ig < num_green; ig++) |
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486 { |
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487 /* int dg = abs(ig - g); */ |
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488 int dg = ((ig > g) ? ig - g : g - ig); |
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489 int dt = dr + dg; |
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490 int dm = ((dr > dg) ? dr : dg); |
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491 int index_g = index_r | (ig << PNG_DITHER_BLUE_BITS); |
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492 |
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493 for (ib = 0; ib < num_blue; ib++) |
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494 { |
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495 int d_index = index_g | ib; |
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496 /* int db = abs(ib - b); */ |
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497 int db = ((ib > b) ? ib - b : b - ib); |
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498 int dmax = ((dm > db) ? dm : db); |
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499 int d = dmax + dt + db; |
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500 |
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501 if (d < (int)distance[d_index]) |
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502 { |
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503 distance[d_index] = (png_byte)d; |
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504 png_ptr->palette_lookup[d_index] = (png_byte)i; |
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505 } |
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506 } |
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507 } |
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508 } |
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509 } |
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510 |
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511 png_free(png_ptr, distance); |
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512 } |
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513 } |
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514 #endif |
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515 |
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516 #if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED) |
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517 /* Transform the image from the file_gamma to the screen_gamma. We |
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518 * only do transformations on images where the file_gamma and screen_gamma |
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519 * are not close reciprocals, otherwise it slows things down slightly, and |
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520 * also needlessly introduces small errors. |
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521 * |
|
522 * We will turn off gamma transformation later if no semitransparent entries |
|
523 * are present in the tRNS array for palette images. We can't do it here |
|
524 * because we don't necessarily have the tRNS chunk yet. |
|
525 */ |
|
526 void PNGAPI |
|
527 png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma) |
|
528 { |
|
529 png_debug(1, "in png_set_gamma\n"); |
|
530 if (png_ptr == NULL) return; |
|
531 if ((fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) || |
|
532 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA) || |
|
533 (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE)) |
|
534 png_ptr->transformations |= PNG_GAMMA; |
|
535 png_ptr->gamma = (float)file_gamma; |
|
536 png_ptr->screen_gamma = (float)scrn_gamma; |
|
537 } |
|
538 #endif |
|
539 |
|
540 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
541 /* Expand paletted images to RGB, expand grayscale images of |
|
542 * less than 8-bit depth to 8-bit depth, and expand tRNS chunks |
|
543 * to alpha channels. |
|
544 */ |
|
545 void PNGAPI |
|
546 png_set_expand(png_structp png_ptr) |
|
547 { |
|
548 png_debug(1, "in png_set_expand\n"); |
|
549 if (png_ptr == NULL) return; |
|
550 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
|
551 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
552 } |
|
553 |
|
554 /* GRR 19990627: the following three functions currently are identical |
|
555 * to png_set_expand(). However, it is entirely reasonable that someone |
|
556 * might wish to expand an indexed image to RGB but *not* expand a single, |
|
557 * fully transparent palette entry to a full alpha channel--perhaps instead |
|
558 * convert tRNS to the grayscale/RGB format (16-bit RGB value), or replace |
|
559 * the transparent color with a particular RGB value, or drop tRNS entirely. |
|
560 * IOW, a future version of the library may make the transformations flag |
|
561 * a bit more fine-grained, with separate bits for each of these three |
|
562 * functions. |
|
563 * |
|
564 * More to the point, these functions make it obvious what libpng will be |
|
565 * doing, whereas "expand" can (and does) mean any number of things. |
|
566 * |
|
567 * GRP 20060307: In libpng-1.4.0, png_set_gray_1_2_4_to_8() was modified |
|
568 * to expand only the sample depth but not to expand the tRNS to alpha. |
|
569 */ |
|
570 |
|
571 /* Expand paletted images to RGB. */ |
|
572 void PNGAPI |
|
573 png_set_palette_to_rgb(png_structp png_ptr) |
|
574 { |
|
575 png_debug(1, "in png_set_palette_to_rgb\n"); |
|
576 if (png_ptr == NULL) return; |
|
577 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
|
578 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
579 } |
|
580 |
|
581 #if !defined(PNG_1_0_X) |
|
582 /* Expand grayscale images of less than 8-bit depth to 8 bits. */ |
|
583 void PNGAPI |
|
584 png_set_expand_gray_1_2_4_to_8(png_structp png_ptr) |
|
585 { |
|
586 png_debug(1, "in png_set_expand_gray_1_2_4_to_8\n"); |
|
587 if (png_ptr == NULL) return; |
|
588 png_ptr->transformations |= PNG_EXPAND; |
|
589 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
590 } |
|
591 #endif |
|
592 |
|
593 #if defined(PNG_1_0_X) || defined(PNG_1_2_X) |
|
594 /* Expand grayscale images of less than 8-bit depth to 8 bits. */ |
|
595 /* Deprecated as of libpng-1.2.9 */ |
|
596 void PNGAPI |
|
597 png_set_gray_1_2_4_to_8(png_structp png_ptr) |
|
598 { |
|
599 png_debug(1, "in png_set_gray_1_2_4_to_8\n"); |
|
600 if (png_ptr == NULL) return; |
|
601 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
|
602 } |
|
603 #endif |
|
604 |
|
605 |
|
606 /* Expand tRNS chunks to alpha channels. */ |
|
607 void PNGAPI |
|
608 png_set_tRNS_to_alpha(png_structp png_ptr) |
|
609 { |
|
610 png_debug(1, "in png_set_tRNS_to_alpha\n"); |
|
611 png_ptr->transformations |= (PNG_EXPAND | PNG_EXPAND_tRNS); |
|
612 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
613 } |
|
614 #endif /* defined(PNG_READ_EXPAND_SUPPORTED) */ |
|
615 |
|
616 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
617 void PNGAPI |
|
618 png_set_gray_to_rgb(png_structp png_ptr) |
|
619 { |
|
620 png_debug(1, "in png_set_gray_to_rgb\n"); |
|
621 png_ptr->transformations |= PNG_GRAY_TO_RGB; |
|
622 png_ptr->flags &= ~PNG_FLAG_ROW_INIT; |
|
623 } |
|
624 #endif |
|
625 |
|
626 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
627 #if defined(PNG_FLOATING_POINT_SUPPORTED) |
|
628 /* Convert a RGB image to a grayscale of the same width. This allows us, |
|
629 * for example, to convert a 24 bpp RGB image into an 8 bpp grayscale image. |
|
630 */ |
|
631 |
|
632 void PNGAPI |
|
633 png_set_rgb_to_gray(png_structp png_ptr, int error_action, double red, |
|
634 double green) |
|
635 { |
|
636 int red_fixed = (int)((float)red*100000.0 + 0.5); |
|
637 int green_fixed = (int)((float)green*100000.0 + 0.5); |
|
638 if (png_ptr == NULL) return; |
|
639 png_set_rgb_to_gray_fixed(png_ptr, error_action, red_fixed, green_fixed); |
|
640 } |
|
641 #endif |
|
642 |
|
643 void PNGAPI |
|
644 png_set_rgb_to_gray_fixed(png_structp png_ptr, int error_action, |
|
645 png_fixed_point red, png_fixed_point green) |
|
646 { |
|
647 png_debug(1, "in png_set_rgb_to_gray\n"); |
|
648 if (png_ptr == NULL) return; |
|
649 switch(error_action) |
|
650 { |
|
651 case 1: png_ptr->transformations |= PNG_RGB_TO_GRAY; |
|
652 break; |
|
653 case 2: png_ptr->transformations |= PNG_RGB_TO_GRAY_WARN; |
|
654 break; |
|
655 case 3: png_ptr->transformations |= PNG_RGB_TO_GRAY_ERR; |
|
656 } |
|
657 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
658 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
659 png_ptr->transformations |= PNG_EXPAND; |
|
660 #else |
|
661 { |
|
662 png_warning(png_ptr, |
|
663 "Cannot do RGB_TO_GRAY without EXPAND_SUPPORTED."); |
|
664 png_ptr->transformations &= ~PNG_RGB_TO_GRAY; |
|
665 } |
|
666 #endif |
|
667 { |
|
668 png_uint_16 red_int, green_int; |
|
669 if (red < 0 || green < 0) |
|
670 { |
|
671 red_int = 6968; /* .212671 * 32768 + .5 */ |
|
672 green_int = 23434; /* .715160 * 32768 + .5 */ |
|
673 } |
|
674 else if (red + green < 100000L) |
|
675 { |
|
676 red_int = (png_uint_16)(((png_uint_32)red*32768L)/100000L); |
|
677 green_int = (png_uint_16)(((png_uint_32)green*32768L)/100000L); |
|
678 } |
|
679 else |
|
680 { |
|
681 png_warning(png_ptr, "ignoring out of range rgb_to_gray coefficients"); |
|
682 red_int = 6968; |
|
683 green_int = 23434; |
|
684 } |
|
685 png_ptr->rgb_to_gray_red_coeff = red_int; |
|
686 png_ptr->rgb_to_gray_green_coeff = green_int; |
|
687 png_ptr->rgb_to_gray_blue_coeff = |
|
688 (png_uint_16)(32768 - red_int - green_int); |
|
689 } |
|
690 } |
|
691 #endif |
|
692 |
|
693 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ |
|
694 defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) || \ |
|
695 defined(PNG_LEGACY_SUPPORTED) |
|
696 void PNGAPI |
|
697 png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr |
|
698 read_user_transform_fn) |
|
699 { |
|
700 png_debug(1, "in png_set_read_user_transform_fn\n"); |
|
701 if (png_ptr == NULL) return; |
|
702 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
|
703 png_ptr->transformations |= PNG_USER_TRANSFORM; |
|
704 png_ptr->read_user_transform_fn = read_user_transform_fn; |
|
705 #endif |
|
706 #ifdef PNG_LEGACY_SUPPORTED |
|
707 if (read_user_transform_fn) |
|
708 png_warning(png_ptr, |
|
709 "This version of libpng does not support user transforms"); |
|
710 #endif |
|
711 } |
|
712 #endif |
|
713 |
|
714 /* Initialize everything needed for the read. This includes modifying |
|
715 * the palette. |
|
716 */ |
|
717 void /* PRIVATE */ |
|
718 png_init_read_transformations(png_structp png_ptr) |
|
719 { |
|
720 png_debug(1, "in png_init_read_transformations\n"); |
|
721 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
722 if (png_ptr != NULL) |
|
723 #endif |
|
724 { |
|
725 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || defined(PNG_READ_SHIFT_SUPPORTED) \ |
|
726 || defined(PNG_READ_GAMMA_SUPPORTED) |
|
727 int color_type = png_ptr->color_type; |
|
728 #endif |
|
729 |
|
730 #if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
731 |
|
732 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
733 /* Detect gray background and attempt to enable optimization |
|
734 * for gray --> RGB case */ |
|
735 /* Note: if PNG_BACKGROUND_EXPAND is set and color_type is either RGB or |
|
736 * RGB_ALPHA (in which case need_expand is superfluous anyway), the |
|
737 * background color might actually be gray yet not be flagged as such. |
|
738 * This is not a problem for the current code, which uses |
|
739 * PNG_BACKGROUND_IS_GRAY only to decide when to do the |
|
740 * png_do_gray_to_rgb() transformation. |
|
741 */ |
|
742 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && |
|
743 !(color_type & PNG_COLOR_MASK_COLOR)) |
|
744 { |
|
745 png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; |
|
746 } else if ((png_ptr->transformations & PNG_BACKGROUND) && |
|
747 !(png_ptr->transformations & PNG_BACKGROUND_EXPAND) && |
|
748 (png_ptr->transformations & PNG_GRAY_TO_RGB) && |
|
749 png_ptr->background.red == png_ptr->background.green && |
|
750 png_ptr->background.red == png_ptr->background.blue) |
|
751 { |
|
752 png_ptr->mode |= PNG_BACKGROUND_IS_GRAY; |
|
753 png_ptr->background.gray = png_ptr->background.red; |
|
754 } |
|
755 #endif |
|
756 |
|
757 if ((png_ptr->transformations & PNG_BACKGROUND_EXPAND) && |
|
758 (png_ptr->transformations & PNG_EXPAND)) |
|
759 { |
|
760 if (!(color_type & PNG_COLOR_MASK_COLOR)) /* i.e., GRAY or GRAY_ALPHA */ |
|
761 { |
|
762 /* expand background and tRNS chunks */ |
|
763 switch (png_ptr->bit_depth) |
|
764 { |
|
765 case 1: |
|
766 png_ptr->background.gray *= (png_uint_16)0xff; |
|
767 png_ptr->background.red = png_ptr->background.green |
|
768 = png_ptr->background.blue = png_ptr->background.gray; |
|
769 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
770 { |
|
771 png_ptr->trans_values.gray *= (png_uint_16)0xff; |
|
772 png_ptr->trans_values.red = png_ptr->trans_values.green |
|
773 = png_ptr->trans_values.blue = png_ptr->trans_values.gray; |
|
774 } |
|
775 break; |
|
776 case 2: |
|
777 png_ptr->background.gray *= (png_uint_16)0x55; |
|
778 png_ptr->background.red = png_ptr->background.green |
|
779 = png_ptr->background.blue = png_ptr->background.gray; |
|
780 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
781 { |
|
782 png_ptr->trans_values.gray *= (png_uint_16)0x55; |
|
783 png_ptr->trans_values.red = png_ptr->trans_values.green |
|
784 = png_ptr->trans_values.blue = png_ptr->trans_values.gray; |
|
785 } |
|
786 break; |
|
787 case 4: |
|
788 png_ptr->background.gray *= (png_uint_16)0x11; |
|
789 png_ptr->background.red = png_ptr->background.green |
|
790 = png_ptr->background.blue = png_ptr->background.gray; |
|
791 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
792 { |
|
793 png_ptr->trans_values.gray *= (png_uint_16)0x11; |
|
794 png_ptr->trans_values.red = png_ptr->trans_values.green |
|
795 = png_ptr->trans_values.blue = png_ptr->trans_values.gray; |
|
796 } |
|
797 break; |
|
798 case 8: |
|
799 case 16: |
|
800 png_ptr->background.red = png_ptr->background.green |
|
801 = png_ptr->background.blue = png_ptr->background.gray; |
|
802 break; |
|
803 } |
|
804 } |
|
805 else if (color_type == PNG_COLOR_TYPE_PALETTE) |
|
806 { |
|
807 png_ptr->background.red = |
|
808 png_ptr->palette[png_ptr->background.index].red; |
|
809 png_ptr->background.green = |
|
810 png_ptr->palette[png_ptr->background.index].green; |
|
811 png_ptr->background.blue = |
|
812 png_ptr->palette[png_ptr->background.index].blue; |
|
813 |
|
814 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
|
815 if (png_ptr->transformations & PNG_INVERT_ALPHA) |
|
816 { |
|
817 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
818 if (!(png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
819 #endif |
|
820 { |
|
821 /* invert the alpha channel (in tRNS) unless the pixels are |
|
822 going to be expanded, in which case leave it for later */ |
|
823 int i, istop; |
|
824 istop=(int)png_ptr->num_trans; |
|
825 for (i=0; i<istop; i++) |
|
826 png_ptr->trans[i] = (png_byte)(255 - png_ptr->trans[i]); |
|
827 } |
|
828 } |
|
829 #endif |
|
830 |
|
831 } |
|
832 } |
|
833 #endif |
|
834 |
|
835 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) |
|
836 png_ptr->background_1 = png_ptr->background; |
|
837 #endif |
|
838 #if defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED) |
|
839 |
|
840 if ((color_type == PNG_COLOR_TYPE_PALETTE && png_ptr->num_trans != 0) |
|
841 && (fabs(png_ptr->screen_gamma * png_ptr->gamma - 1.0) |
|
842 < PNG_GAMMA_THRESHOLD)) |
|
843 { |
|
844 int i, k; |
|
845 k=0; |
|
846 for (i=0; i<png_ptr->num_trans; i++) |
|
847 { |
|
848 if (png_ptr->trans[i] != 0 && png_ptr->trans[i] != 0xff) |
|
849 k=1; /* partial transparency is present */ |
|
850 } |
|
851 if (k == 0) |
|
852 png_ptr->transformations &= ~PNG_GAMMA; |
|
853 } |
|
854 |
|
855 if ((png_ptr->transformations & (PNG_GAMMA | PNG_RGB_TO_GRAY)) && |
|
856 png_ptr->gamma != 0.0) |
|
857 { |
|
858 png_build_gamma_table(png_ptr); |
|
859 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
860 if (png_ptr->transformations & PNG_BACKGROUND) |
|
861 { |
|
862 if (color_type == PNG_COLOR_TYPE_PALETTE) |
|
863 { |
|
864 /* could skip if no transparency and |
|
865 */ |
|
866 png_color back, back_1; |
|
867 png_colorp palette = png_ptr->palette; |
|
868 int num_palette = png_ptr->num_palette; |
|
869 int i; |
|
870 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
|
871 { |
|
872 back.red = png_ptr->gamma_table[png_ptr->background.red]; |
|
873 back.green = png_ptr->gamma_table[png_ptr->background.green]; |
|
874 back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
|
875 |
|
876 back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
|
877 back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
|
878 back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
|
879 } |
|
880 else |
|
881 { |
|
882 double g, gs; |
|
883 |
|
884 switch (png_ptr->background_gamma_type) |
|
885 { |
|
886 case PNG_BACKGROUND_GAMMA_SCREEN: |
|
887 g = (png_ptr->screen_gamma); |
|
888 gs = 1.0; |
|
889 break; |
|
890 case PNG_BACKGROUND_GAMMA_FILE: |
|
891 g = 1.0 / (png_ptr->gamma); |
|
892 gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
|
893 break; |
|
894 case PNG_BACKGROUND_GAMMA_UNIQUE: |
|
895 g = 1.0 / (png_ptr->background_gamma); |
|
896 gs = 1.0 / (png_ptr->background_gamma * |
|
897 png_ptr->screen_gamma); |
|
898 break; |
|
899 default: |
|
900 g = 1.0; /* back_1 */ |
|
901 gs = 1.0; /* back */ |
|
902 } |
|
903 |
|
904 if ( fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD) |
|
905 { |
|
906 back.red = (png_byte)png_ptr->background.red; |
|
907 back.green = (png_byte)png_ptr->background.green; |
|
908 back.blue = (png_byte)png_ptr->background.blue; |
|
909 } |
|
910 else |
|
911 { |
|
912 back.red = (png_byte)(pow( |
|
913 (double)png_ptr->background.red/255, gs) * 255.0 + .5); |
|
914 back.green = (png_byte)(pow( |
|
915 (double)png_ptr->background.green/255, gs) * 255.0 + .5); |
|
916 back.blue = (png_byte)(pow( |
|
917 (double)png_ptr->background.blue/255, gs) * 255.0 + .5); |
|
918 } |
|
919 |
|
920 back_1.red = (png_byte)(pow( |
|
921 (double)png_ptr->background.red/255, g) * 255.0 + .5); |
|
922 back_1.green = (png_byte)(pow( |
|
923 (double)png_ptr->background.green/255, g) * 255.0 + .5); |
|
924 back_1.blue = (png_byte)(pow( |
|
925 (double)png_ptr->background.blue/255, g) * 255.0 + .5); |
|
926 } |
|
927 for (i = 0; i < num_palette; i++) |
|
928 { |
|
929 if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff) |
|
930 { |
|
931 if (png_ptr->trans[i] == 0) |
|
932 { |
|
933 palette[i] = back; |
|
934 } |
|
935 else /* if (png_ptr->trans[i] != 0xff) */ |
|
936 { |
|
937 png_byte v, w; |
|
938 |
|
939 v = png_ptr->gamma_to_1[palette[i].red]; |
|
940 png_composite(w, v, png_ptr->trans[i], back_1.red); |
|
941 palette[i].red = png_ptr->gamma_from_1[w]; |
|
942 |
|
943 v = png_ptr->gamma_to_1[palette[i].green]; |
|
944 png_composite(w, v, png_ptr->trans[i], back_1.green); |
|
945 palette[i].green = png_ptr->gamma_from_1[w]; |
|
946 |
|
947 v = png_ptr->gamma_to_1[palette[i].blue]; |
|
948 png_composite(w, v, png_ptr->trans[i], back_1.blue); |
|
949 palette[i].blue = png_ptr->gamma_from_1[w]; |
|
950 } |
|
951 } |
|
952 else |
|
953 { |
|
954 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
955 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
956 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
957 } |
|
958 } |
|
959 /* Prevent the transformations being done again, and make sure |
|
960 * that the now spurious alpha channel is stripped - the code |
|
961 * has just reduced background composition and gamma correction |
|
962 * to a simple alpha channel strip. |
|
963 */ |
|
964 png_ptr->transformations &= ~PNG_BACKGROUND; |
|
965 png_ptr->transformations &= ~PNG_GAMMA; |
|
966 png_ptr->transformations |= PNG_STRIP_ALPHA; |
|
967 } |
|
968 /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN) */ |
|
969 else |
|
970 /* color_type != PNG_COLOR_TYPE_PALETTE */ |
|
971 { |
|
972 double m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1); |
|
973 double g = 1.0; |
|
974 double gs = 1.0; |
|
975 |
|
976 switch (png_ptr->background_gamma_type) |
|
977 { |
|
978 case PNG_BACKGROUND_GAMMA_SCREEN: |
|
979 g = (png_ptr->screen_gamma); |
|
980 gs = 1.0; |
|
981 break; |
|
982 case PNG_BACKGROUND_GAMMA_FILE: |
|
983 g = 1.0 / (png_ptr->gamma); |
|
984 gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
|
985 break; |
|
986 case PNG_BACKGROUND_GAMMA_UNIQUE: |
|
987 g = 1.0 / (png_ptr->background_gamma); |
|
988 gs = 1.0 / (png_ptr->background_gamma * |
|
989 png_ptr->screen_gamma); |
|
990 break; |
|
991 } |
|
992 |
|
993 png_ptr->background_1.gray = (png_uint_16)(pow( |
|
994 (double)png_ptr->background.gray / m, g) * m + .5); |
|
995 png_ptr->background.gray = (png_uint_16)(pow( |
|
996 (double)png_ptr->background.gray / m, gs) * m + .5); |
|
997 |
|
998 if ((png_ptr->background.red != png_ptr->background.green) || |
|
999 (png_ptr->background.red != png_ptr->background.blue) || |
|
1000 (png_ptr->background.red != png_ptr->background.gray)) |
|
1001 { |
|
1002 /* RGB or RGBA with color background */ |
|
1003 png_ptr->background_1.red = (png_uint_16)(pow( |
|
1004 (double)png_ptr->background.red / m, g) * m + .5); |
|
1005 png_ptr->background_1.green = (png_uint_16)(pow( |
|
1006 (double)png_ptr->background.green / m, g) * m + .5); |
|
1007 png_ptr->background_1.blue = (png_uint_16)(pow( |
|
1008 (double)png_ptr->background.blue / m, g) * m + .5); |
|
1009 png_ptr->background.red = (png_uint_16)(pow( |
|
1010 (double)png_ptr->background.red / m, gs) * m + .5); |
|
1011 png_ptr->background.green = (png_uint_16)(pow( |
|
1012 (double)png_ptr->background.green / m, gs) * m + .5); |
|
1013 png_ptr->background.blue = (png_uint_16)(pow( |
|
1014 (double)png_ptr->background.blue / m, gs) * m + .5); |
|
1015 } |
|
1016 else |
|
1017 { |
|
1018 /* GRAY, GRAY ALPHA, RGB, or RGBA with gray background */ |
|
1019 png_ptr->background_1.red = png_ptr->background_1.green |
|
1020 = png_ptr->background_1.blue = png_ptr->background_1.gray; |
|
1021 png_ptr->background.red = png_ptr->background.green |
|
1022 = png_ptr->background.blue = png_ptr->background.gray; |
|
1023 } |
|
1024 } |
|
1025 } |
|
1026 else |
|
1027 /* transformation does not include PNG_BACKGROUND */ |
|
1028 #endif /* PNG_READ_BACKGROUND_SUPPORTED */ |
|
1029 if (color_type == PNG_COLOR_TYPE_PALETTE) |
|
1030 { |
|
1031 png_colorp palette = png_ptr->palette; |
|
1032 int num_palette = png_ptr->num_palette; |
|
1033 int i; |
|
1034 |
|
1035 for (i = 0; i < num_palette; i++) |
|
1036 { |
|
1037 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
1038 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
1039 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
1040 } |
|
1041 |
|
1042 /* Done the gamma correction. */ |
|
1043 png_ptr->transformations &= ~PNG_GAMMA; |
|
1044 } |
|
1045 } |
|
1046 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1047 else |
|
1048 #endif |
|
1049 #endif /* PNG_READ_GAMMA_SUPPORTED && PNG_FLOATING_POINT_SUPPORTED */ |
|
1050 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1051 /* No GAMMA transformation */ |
|
1052 if ((png_ptr->transformations & PNG_BACKGROUND) && |
|
1053 (color_type == PNG_COLOR_TYPE_PALETTE)) |
|
1054 { |
|
1055 int i; |
|
1056 int istop = (int)png_ptr->num_trans; |
|
1057 png_color back; |
|
1058 png_colorp palette = png_ptr->palette; |
|
1059 |
|
1060 back.red = (png_byte)png_ptr->background.red; |
|
1061 back.green = (png_byte)png_ptr->background.green; |
|
1062 back.blue = (png_byte)png_ptr->background.blue; |
|
1063 |
|
1064 for (i = 0; i < istop; i++) |
|
1065 { |
|
1066 if (png_ptr->trans[i] == 0) |
|
1067 { |
|
1068 palette[i] = back; |
|
1069 } |
|
1070 else if (png_ptr->trans[i] != 0xff) |
|
1071 { |
|
1072 /* The png_composite() macro is defined in png.h */ |
|
1073 png_composite(palette[i].red, palette[i].red, |
|
1074 png_ptr->trans[i], back.red); |
|
1075 png_composite(palette[i].green, palette[i].green, |
|
1076 png_ptr->trans[i], back.green); |
|
1077 png_composite(palette[i].blue, palette[i].blue, |
|
1078 png_ptr->trans[i], back.blue); |
|
1079 } |
|
1080 } |
|
1081 |
|
1082 /* Handled alpha, still need to strip the channel. */ |
|
1083 png_ptr->transformations &= ~PNG_BACKGROUND; |
|
1084 png_ptr->transformations |= PNG_STRIP_ALPHA; |
|
1085 } |
|
1086 #endif /* PNG_READ_BACKGROUND_SUPPORTED */ |
|
1087 |
|
1088 #if defined(PNG_READ_SHIFT_SUPPORTED) |
|
1089 if ((png_ptr->transformations & PNG_SHIFT) && |
|
1090 (color_type == PNG_COLOR_TYPE_PALETTE)) |
|
1091 { |
|
1092 png_uint_16 i; |
|
1093 png_uint_16 istop = png_ptr->num_palette; |
|
1094 int sr = 8 - png_ptr->sig_bit.red; |
|
1095 int sg = 8 - png_ptr->sig_bit.green; |
|
1096 int sb = 8 - png_ptr->sig_bit.blue; |
|
1097 |
|
1098 if (sr < 0 || sr > 8) |
|
1099 sr = 0; |
|
1100 if (sg < 0 || sg > 8) |
|
1101 sg = 0; |
|
1102 if (sb < 0 || sb > 8) |
|
1103 sb = 0; |
|
1104 for (i = 0; i < istop; i++) |
|
1105 { |
|
1106 png_ptr->palette[i].red >>= sr; |
|
1107 png_ptr->palette[i].green >>= sg; |
|
1108 png_ptr->palette[i].blue >>= sb; |
|
1109 } |
|
1110 } |
|
1111 #endif /* PNG_READ_SHIFT_SUPPORTED */ |
|
1112 } |
|
1113 #if !defined(PNG_READ_GAMMA_SUPPORTED) && !defined(PNG_READ_SHIFT_SUPPORTED) \ |
|
1114 && !defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1115 if (png_ptr) |
|
1116 return; |
|
1117 #endif |
|
1118 } |
|
1119 |
|
1120 /* Modify the info structure to reflect the transformations. The |
|
1121 * info should be updated so a PNG file could be written with it, |
|
1122 * assuming the transformations result in valid PNG data. |
|
1123 */ |
|
1124 void /* PRIVATE */ |
|
1125 png_read_transform_info(png_structp png_ptr, png_infop info_ptr) |
|
1126 { |
|
1127 png_debug(1, "in png_read_transform_info\n"); |
|
1128 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
1129 if (png_ptr->transformations & PNG_EXPAND) |
|
1130 { |
|
1131 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
1132 { |
|
1133 if (png_ptr->num_trans && |
|
1134 (png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
1135 info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
|
1136 else |
|
1137 info_ptr->color_type = PNG_COLOR_TYPE_RGB; |
|
1138 info_ptr->bit_depth = 8; |
|
1139 info_ptr->num_trans = 0; |
|
1140 } |
|
1141 else |
|
1142 { |
|
1143 if (png_ptr->num_trans) |
|
1144 { |
|
1145 if (png_ptr->transformations & PNG_EXPAND_tRNS) |
|
1146 info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
|
1147 #if 0 /* Removed from libpng-1.2.27 */ |
|
1148 else |
|
1149 info_ptr->color_type |= PNG_COLOR_MASK_COLOR; |
|
1150 #endif |
|
1151 } |
|
1152 if (info_ptr->bit_depth < 8) |
|
1153 info_ptr->bit_depth = 8; |
|
1154 info_ptr->num_trans = 0; |
|
1155 } |
|
1156 } |
|
1157 #endif |
|
1158 |
|
1159 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1160 if (png_ptr->transformations & PNG_BACKGROUND) |
|
1161 { |
|
1162 info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; |
|
1163 info_ptr->num_trans = 0; |
|
1164 info_ptr->background = png_ptr->background; |
|
1165 } |
|
1166 #endif |
|
1167 |
|
1168 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
1169 if (png_ptr->transformations & PNG_GAMMA) |
|
1170 { |
|
1171 #ifdef PNG_FLOATING_POINT_SUPPORTED |
|
1172 info_ptr->gamma = png_ptr->gamma; |
|
1173 #endif |
|
1174 #ifdef PNG_FIXED_POINT_SUPPORTED |
|
1175 info_ptr->int_gamma = png_ptr->int_gamma; |
|
1176 #endif |
|
1177 } |
|
1178 #endif |
|
1179 |
|
1180 #if defined(PNG_READ_16_TO_8_SUPPORTED) |
|
1181 if ((png_ptr->transformations & PNG_16_TO_8) && (info_ptr->bit_depth == 16)) |
|
1182 info_ptr->bit_depth = 8; |
|
1183 #endif |
|
1184 |
|
1185 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
1186 if (png_ptr->transformations & PNG_GRAY_TO_RGB) |
|
1187 info_ptr->color_type |= PNG_COLOR_MASK_COLOR; |
|
1188 #endif |
|
1189 |
|
1190 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
1191 if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
|
1192 info_ptr->color_type &= ~PNG_COLOR_MASK_COLOR; |
|
1193 #endif |
|
1194 |
|
1195 #if defined(PNG_READ_DITHER_SUPPORTED) |
|
1196 if (png_ptr->transformations & PNG_DITHER) |
|
1197 { |
|
1198 if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || |
|
1199 (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && |
|
1200 png_ptr->palette_lookup && info_ptr->bit_depth == 8) |
|
1201 { |
|
1202 info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; |
|
1203 } |
|
1204 } |
|
1205 #endif |
|
1206 |
|
1207 #if defined(PNG_READ_PACK_SUPPORTED) |
|
1208 if ((png_ptr->transformations & PNG_PACK) && (info_ptr->bit_depth < 8)) |
|
1209 info_ptr->bit_depth = 8; |
|
1210 #endif |
|
1211 |
|
1212 if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
1213 info_ptr->channels = 1; |
|
1214 else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) |
|
1215 info_ptr->channels = 3; |
|
1216 else |
|
1217 info_ptr->channels = 1; |
|
1218 |
|
1219 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
|
1220 if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) |
|
1221 info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; |
|
1222 #endif |
|
1223 |
|
1224 if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) |
|
1225 info_ptr->channels++; |
|
1226 |
|
1227 #if defined(PNG_READ_FILLER_SUPPORTED) |
|
1228 /* STRIP_ALPHA and FILLER allowed: MASK_ALPHA bit stripped above */ |
|
1229 if ((png_ptr->transformations & PNG_FILLER) && |
|
1230 ((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || |
|
1231 (info_ptr->color_type == PNG_COLOR_TYPE_GRAY))) |
|
1232 { |
|
1233 info_ptr->channels++; |
|
1234 /* if adding a true alpha channel not just filler */ |
|
1235 #if !defined(PNG_1_0_X) |
|
1236 if (png_ptr->transformations & PNG_ADD_ALPHA) |
|
1237 info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; |
|
1238 #endif |
|
1239 } |
|
1240 #endif |
|
1241 |
|
1242 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) && \ |
|
1243 defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
|
1244 if (png_ptr->transformations & PNG_USER_TRANSFORM) |
|
1245 { |
|
1246 if (info_ptr->bit_depth < png_ptr->user_transform_depth) |
|
1247 info_ptr->bit_depth = png_ptr->user_transform_depth; |
|
1248 if (info_ptr->channels < png_ptr->user_transform_channels) |
|
1249 info_ptr->channels = png_ptr->user_transform_channels; |
|
1250 } |
|
1251 #endif |
|
1252 |
|
1253 info_ptr->pixel_depth = (png_byte)(info_ptr->channels * |
|
1254 info_ptr->bit_depth); |
|
1255 |
|
1256 info_ptr->rowbytes = PNG_ROWBYTES(info_ptr->pixel_depth, info_ptr->width); |
|
1257 |
|
1258 #if !defined(PNG_READ_EXPAND_SUPPORTED) |
|
1259 if (png_ptr) |
|
1260 return; |
|
1261 #endif |
|
1262 } |
|
1263 |
|
1264 /* Transform the row. The order of transformations is significant, |
|
1265 * and is very touchy. If you add a transformation, take care to |
|
1266 * decide how it fits in with the other transformations here. |
|
1267 */ |
|
1268 void /* PRIVATE */ |
|
1269 png_do_read_transformations(png_structp png_ptr) |
|
1270 { |
|
1271 png_debug(1, "in png_do_read_transformations\n"); |
|
1272 if (png_ptr->row_buf == NULL) |
|
1273 { |
|
1274 #if !defined(PNG_NO_STDIO) && !defined(_WIN32_WCE) |
|
1275 char msg[50]; |
|
1276 |
|
1277 png_snprintf2(msg, 50, |
|
1278 "NULL row buffer for row %ld, pass %d", (long)png_ptr->row_number, |
|
1279 png_ptr->pass); |
|
1280 png_error(png_ptr, msg); |
|
1281 #else |
|
1282 png_error(png_ptr, "NULL row buffer"); |
|
1283 #endif |
|
1284 } |
|
1285 #ifdef PNG_WARN_UNINITIALIZED_ROW |
|
1286 if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) |
|
1287 /* Application has failed to call either png_read_start_image() |
|
1288 * or png_read_update_info() after setting transforms that expand |
|
1289 * pixels. This check added to libpng-1.2.19 */ |
|
1290 #if (PNG_WARN_UNINITIALIZED_ROW==1) |
|
1291 png_error(png_ptr, "Uninitialized row"); |
|
1292 #else |
|
1293 png_warning(png_ptr, "Uninitialized row"); |
|
1294 #endif |
|
1295 #endif |
|
1296 |
|
1297 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
1298 if (png_ptr->transformations & PNG_EXPAND) |
|
1299 { |
|
1300 if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE) |
|
1301 { |
|
1302 png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1303 png_ptr->palette, png_ptr->trans, png_ptr->num_trans); |
|
1304 } |
|
1305 else |
|
1306 { |
|
1307 if (png_ptr->num_trans && |
|
1308 (png_ptr->transformations & PNG_EXPAND_tRNS)) |
|
1309 png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1310 &(png_ptr->trans_values)); |
|
1311 else |
|
1312 png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1313 NULL); |
|
1314 } |
|
1315 } |
|
1316 #endif |
|
1317 |
|
1318 #if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) |
|
1319 if (png_ptr->flags & PNG_FLAG_STRIP_ALPHA) |
|
1320 png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1321 PNG_FLAG_FILLER_AFTER | (png_ptr->flags & PNG_FLAG_STRIP_ALPHA)); |
|
1322 #endif |
|
1323 |
|
1324 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
1325 if (png_ptr->transformations & PNG_RGB_TO_GRAY) |
|
1326 { |
|
1327 int rgb_error = |
|
1328 png_do_rgb_to_gray(png_ptr, &(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1329 if (rgb_error) |
|
1330 { |
|
1331 png_ptr->rgb_to_gray_status=1; |
|
1332 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == |
|
1333 PNG_RGB_TO_GRAY_WARN) |
|
1334 png_warning(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
|
1335 if ((png_ptr->transformations & PNG_RGB_TO_GRAY) == |
|
1336 PNG_RGB_TO_GRAY_ERR) |
|
1337 png_error(png_ptr, "png_do_rgb_to_gray found nongray pixel"); |
|
1338 } |
|
1339 } |
|
1340 #endif |
|
1341 |
|
1342 /* |
|
1343 From Andreas Dilger e-mail to png-implement, 26 March 1998: |
|
1344 |
|
1345 In most cases, the "simple transparency" should be done prior to doing |
|
1346 gray-to-RGB, or you will have to test 3x as many bytes to check if a |
|
1347 pixel is transparent. You would also need to make sure that the |
|
1348 transparency information is upgraded to RGB. |
|
1349 |
|
1350 To summarize, the current flow is: |
|
1351 - Gray + simple transparency -> compare 1 or 2 gray bytes and composite |
|
1352 with background "in place" if transparent, |
|
1353 convert to RGB if necessary |
|
1354 - Gray + alpha -> composite with gray background and remove alpha bytes, |
|
1355 convert to RGB if necessary |
|
1356 |
|
1357 To support RGB backgrounds for gray images we need: |
|
1358 - Gray + simple transparency -> convert to RGB + simple transparency, compare |
|
1359 3 or 6 bytes and composite with background |
|
1360 "in place" if transparent (3x compare/pixel |
|
1361 compared to doing composite with gray bkgrnd) |
|
1362 - Gray + alpha -> convert to RGB + alpha, composite with background and |
|
1363 remove alpha bytes (3x float operations/pixel |
|
1364 compared with composite on gray background) |
|
1365 |
|
1366 Greg's change will do this. The reason it wasn't done before is for |
|
1367 performance, as this increases the per-pixel operations. If we would check |
|
1368 in advance if the background was gray or RGB, and position the gray-to-RGB |
|
1369 transform appropriately, then it would save a lot of work/time. |
|
1370 */ |
|
1371 |
|
1372 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
1373 /* if gray -> RGB, do so now only if background is non-gray; else do later |
|
1374 * for performance reasons */ |
|
1375 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && |
|
1376 !(png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) |
|
1377 png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1378 #endif |
|
1379 |
|
1380 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1381 if ((png_ptr->transformations & PNG_BACKGROUND) && |
|
1382 ((png_ptr->num_trans != 0 ) || |
|
1383 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) |
|
1384 png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1385 &(png_ptr->trans_values), &(png_ptr->background) |
|
1386 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
1387 , &(png_ptr->background_1), |
|
1388 png_ptr->gamma_table, png_ptr->gamma_from_1, |
|
1389 png_ptr->gamma_to_1, png_ptr->gamma_16_table, |
|
1390 png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1, |
|
1391 png_ptr->gamma_shift |
|
1392 #endif |
|
1393 ); |
|
1394 #endif |
|
1395 |
|
1396 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
1397 if ((png_ptr->transformations & PNG_GAMMA) && |
|
1398 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
1399 !((png_ptr->transformations & PNG_BACKGROUND) && |
|
1400 ((png_ptr->num_trans != 0) || |
|
1401 (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) && |
|
1402 #endif |
|
1403 (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) |
|
1404 png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1405 png_ptr->gamma_table, png_ptr->gamma_16_table, |
|
1406 png_ptr->gamma_shift); |
|
1407 #endif |
|
1408 |
|
1409 #if defined(PNG_READ_16_TO_8_SUPPORTED) |
|
1410 if (png_ptr->transformations & PNG_16_TO_8) |
|
1411 png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1412 #endif |
|
1413 |
|
1414 #if defined(PNG_READ_DITHER_SUPPORTED) |
|
1415 if (png_ptr->transformations & PNG_DITHER) |
|
1416 { |
|
1417 png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1418 png_ptr->palette_lookup, png_ptr->dither_index); |
|
1419 if (png_ptr->row_info.rowbytes == (png_uint_32)0) |
|
1420 png_error(png_ptr, "png_do_dither returned rowbytes=0"); |
|
1421 } |
|
1422 #endif |
|
1423 |
|
1424 #if defined(PNG_READ_INVERT_SUPPORTED) |
|
1425 if (png_ptr->transformations & PNG_INVERT_MONO) |
|
1426 png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1427 #endif |
|
1428 |
|
1429 #if defined(PNG_READ_SHIFT_SUPPORTED) |
|
1430 if (png_ptr->transformations & PNG_SHIFT) |
|
1431 png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1432 &(png_ptr->shift)); |
|
1433 #endif |
|
1434 |
|
1435 #if defined(PNG_READ_PACK_SUPPORTED) |
|
1436 if (png_ptr->transformations & PNG_PACK) |
|
1437 png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1438 #endif |
|
1439 |
|
1440 #if defined(PNG_READ_BGR_SUPPORTED) |
|
1441 if (png_ptr->transformations & PNG_BGR) |
|
1442 png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1443 #endif |
|
1444 |
|
1445 #if defined(PNG_READ_PACKSWAP_SUPPORTED) |
|
1446 if (png_ptr->transformations & PNG_PACKSWAP) |
|
1447 png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1448 #endif |
|
1449 |
|
1450 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
1451 /* if gray -> RGB, do so now only if we did not do so above */ |
|
1452 if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && |
|
1453 (png_ptr->mode & PNG_BACKGROUND_IS_GRAY)) |
|
1454 png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1455 #endif |
|
1456 |
|
1457 #if defined(PNG_READ_FILLER_SUPPORTED) |
|
1458 if (png_ptr->transformations & PNG_FILLER) |
|
1459 png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, |
|
1460 (png_uint_32)png_ptr->filler, png_ptr->flags); |
|
1461 #endif |
|
1462 |
|
1463 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
|
1464 if (png_ptr->transformations & PNG_INVERT_ALPHA) |
|
1465 png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1466 #endif |
|
1467 |
|
1468 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) |
|
1469 if (png_ptr->transformations & PNG_SWAP_ALPHA) |
|
1470 png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1471 #endif |
|
1472 |
|
1473 #if defined(PNG_READ_SWAP_SUPPORTED) |
|
1474 if (png_ptr->transformations & PNG_SWAP_BYTES) |
|
1475 png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); |
|
1476 #endif |
|
1477 |
|
1478 #if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) |
|
1479 if (png_ptr->transformations & PNG_USER_TRANSFORM) |
|
1480 { |
|
1481 if (png_ptr->read_user_transform_fn != NULL) |
|
1482 (*(png_ptr->read_user_transform_fn)) /* user read transform function */ |
|
1483 (png_ptr, /* png_ptr */ |
|
1484 &(png_ptr->row_info), /* row_info: */ |
|
1485 /* png_uint_32 width; width of row */ |
|
1486 /* png_uint_32 rowbytes; number of bytes in row */ |
|
1487 /* png_byte color_type; color type of pixels */ |
|
1488 /* png_byte bit_depth; bit depth of samples */ |
|
1489 /* png_byte channels; number of channels (1-4) */ |
|
1490 /* png_byte pixel_depth; bits per pixel (depth*channels) */ |
|
1491 png_ptr->row_buf + 1); /* start of pixel data for row */ |
|
1492 #if defined(PNG_USER_TRANSFORM_PTR_SUPPORTED) |
|
1493 if (png_ptr->user_transform_depth) |
|
1494 png_ptr->row_info.bit_depth = png_ptr->user_transform_depth; |
|
1495 if (png_ptr->user_transform_channels) |
|
1496 png_ptr->row_info.channels = png_ptr->user_transform_channels; |
|
1497 #endif |
|
1498 png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * |
|
1499 png_ptr->row_info.channels); |
|
1500 png_ptr->row_info.rowbytes = PNG_ROWBYTES(png_ptr->row_info.pixel_depth, |
|
1501 png_ptr->row_info.width); |
|
1502 } |
|
1503 #endif |
|
1504 |
|
1505 } |
|
1506 |
|
1507 #if defined(PNG_READ_PACK_SUPPORTED) |
|
1508 /* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, |
|
1509 * without changing the actual values. Thus, if you had a row with |
|
1510 * a bit depth of 1, you would end up with bytes that only contained |
|
1511 * the numbers 0 or 1. If you would rather they contain 0 and 255, use |
|
1512 * png_do_shift() after this. |
|
1513 */ |
|
1514 void /* PRIVATE */ |
|
1515 png_do_unpack(png_row_infop row_info, png_bytep row) |
|
1516 { |
|
1517 png_debug(1, "in png_do_unpack\n"); |
|
1518 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
1519 if (row != NULL && row_info != NULL && row_info->bit_depth < 8) |
|
1520 #else |
|
1521 if (row_info->bit_depth < 8) |
|
1522 #endif |
|
1523 { |
|
1524 png_uint_32 i; |
|
1525 png_uint_32 row_width=row_info->width; |
|
1526 |
|
1527 switch (row_info->bit_depth) |
|
1528 { |
|
1529 case 1: |
|
1530 { |
|
1531 png_bytep sp = row + (png_size_t)((row_width - 1) >> 3); |
|
1532 png_bytep dp = row + (png_size_t)row_width - 1; |
|
1533 png_uint_32 shift = 7 - (int)((row_width + 7) & 0x07); |
|
1534 for (i = 0; i < row_width; i++) |
|
1535 { |
|
1536 *dp = (png_byte)((*sp >> shift) & 0x01); |
|
1537 if (shift == 7) |
|
1538 { |
|
1539 shift = 0; |
|
1540 sp--; |
|
1541 } |
|
1542 else |
|
1543 shift++; |
|
1544 |
|
1545 dp--; |
|
1546 } |
|
1547 break; |
|
1548 } |
|
1549 case 2: |
|
1550 { |
|
1551 |
|
1552 png_bytep sp = row + (png_size_t)((row_width - 1) >> 2); |
|
1553 png_bytep dp = row + (png_size_t)row_width - 1; |
|
1554 png_uint_32 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
|
1555 for (i = 0; i < row_width; i++) |
|
1556 { |
|
1557 *dp = (png_byte)((*sp >> shift) & 0x03); |
|
1558 if (shift == 6) |
|
1559 { |
|
1560 shift = 0; |
|
1561 sp--; |
|
1562 } |
|
1563 else |
|
1564 shift += 2; |
|
1565 |
|
1566 dp--; |
|
1567 } |
|
1568 break; |
|
1569 } |
|
1570 case 4: |
|
1571 { |
|
1572 png_bytep sp = row + (png_size_t)((row_width - 1) >> 1); |
|
1573 png_bytep dp = row + (png_size_t)row_width - 1; |
|
1574 png_uint_32 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); |
|
1575 for (i = 0; i < row_width; i++) |
|
1576 { |
|
1577 *dp = (png_byte)((*sp >> shift) & 0x0f); |
|
1578 if (shift == 4) |
|
1579 { |
|
1580 shift = 0; |
|
1581 sp--; |
|
1582 } |
|
1583 else |
|
1584 shift = 4; |
|
1585 |
|
1586 dp--; |
|
1587 } |
|
1588 break; |
|
1589 } |
|
1590 } |
|
1591 row_info->bit_depth = 8; |
|
1592 row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
|
1593 row_info->rowbytes = row_width * row_info->channels; |
|
1594 } |
|
1595 } |
|
1596 #endif |
|
1597 |
|
1598 #if defined(PNG_READ_SHIFT_SUPPORTED) |
|
1599 /* Reverse the effects of png_do_shift. This routine merely shifts the |
|
1600 * pixels back to their significant bits values. Thus, if you have |
|
1601 * a row of bit depth 8, but only 5 are significant, this will shift |
|
1602 * the values back to 0 through 31. |
|
1603 */ |
|
1604 void /* PRIVATE */ |
|
1605 png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits) |
|
1606 { |
|
1607 png_debug(1, "in png_do_unshift\n"); |
|
1608 if ( |
|
1609 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
1610 row != NULL && row_info != NULL && sig_bits != NULL && |
|
1611 #endif |
|
1612 row_info->color_type != PNG_COLOR_TYPE_PALETTE) |
|
1613 { |
|
1614 int shift[4]; |
|
1615 int channels = 0; |
|
1616 int c; |
|
1617 png_uint_16 value = 0; |
|
1618 png_uint_32 row_width = row_info->width; |
|
1619 |
|
1620 if (row_info->color_type & PNG_COLOR_MASK_COLOR) |
|
1621 { |
|
1622 shift[channels++] = row_info->bit_depth - sig_bits->red; |
|
1623 shift[channels++] = row_info->bit_depth - sig_bits->green; |
|
1624 shift[channels++] = row_info->bit_depth - sig_bits->blue; |
|
1625 } |
|
1626 else |
|
1627 { |
|
1628 shift[channels++] = row_info->bit_depth - sig_bits->gray; |
|
1629 } |
|
1630 if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
|
1631 { |
|
1632 shift[channels++] = row_info->bit_depth - sig_bits->alpha; |
|
1633 } |
|
1634 |
|
1635 for (c = 0; c < channels; c++) |
|
1636 { |
|
1637 if (shift[c] <= 0) |
|
1638 shift[c] = 0; |
|
1639 else |
|
1640 value = 1; |
|
1641 } |
|
1642 |
|
1643 if (!value) |
|
1644 return; |
|
1645 |
|
1646 switch (row_info->bit_depth) |
|
1647 { |
|
1648 case 2: |
|
1649 { |
|
1650 png_bytep bp; |
|
1651 png_uint_32 i; |
|
1652 png_uint_32 istop = row_info->rowbytes; |
|
1653 |
|
1654 for (bp = row, i = 0; i < istop; i++) |
|
1655 { |
|
1656 *bp >>= 1; |
|
1657 *bp++ &= 0x55; |
|
1658 } |
|
1659 break; |
|
1660 } |
|
1661 case 4: |
|
1662 { |
|
1663 png_bytep bp = row; |
|
1664 png_uint_32 i; |
|
1665 png_uint_32 istop = row_info->rowbytes; |
|
1666 png_byte mask = (png_byte)((((int)0xf0 >> shift[0]) & (int)0xf0) | |
|
1667 (png_byte)((int)0xf >> shift[0])); |
|
1668 |
|
1669 for (i = 0; i < istop; i++) |
|
1670 { |
|
1671 *bp >>= shift[0]; |
|
1672 *bp++ &= mask; |
|
1673 } |
|
1674 break; |
|
1675 } |
|
1676 case 8: |
|
1677 { |
|
1678 png_bytep bp = row; |
|
1679 png_uint_32 i; |
|
1680 png_uint_32 istop = row_width * channels; |
|
1681 |
|
1682 for (i = 0; i < istop; i++) |
|
1683 { |
|
1684 *bp++ >>= shift[i%channels]; |
|
1685 } |
|
1686 break; |
|
1687 } |
|
1688 case 16: |
|
1689 { |
|
1690 png_bytep bp = row; |
|
1691 png_uint_32 i; |
|
1692 png_uint_32 istop = channels * row_width; |
|
1693 |
|
1694 for (i = 0; i < istop; i++) |
|
1695 { |
|
1696 value = (png_uint_16)((*bp << 8) + *(bp + 1)); |
|
1697 value >>= shift[i%channels]; |
|
1698 *bp++ = (png_byte)(value >> 8); |
|
1699 *bp++ = (png_byte)(value & 0xff); |
|
1700 } |
|
1701 break; |
|
1702 } |
|
1703 } |
|
1704 } |
|
1705 } |
|
1706 #endif |
|
1707 |
|
1708 #if defined(PNG_READ_16_TO_8_SUPPORTED) |
|
1709 /* chop rows of bit depth 16 down to 8 */ |
|
1710 void /* PRIVATE */ |
|
1711 png_do_chop(png_row_infop row_info, png_bytep row) |
|
1712 { |
|
1713 png_debug(1, "in png_do_chop\n"); |
|
1714 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
1715 if (row != NULL && row_info != NULL && row_info->bit_depth == 16) |
|
1716 #else |
|
1717 if (row_info->bit_depth == 16) |
|
1718 #endif |
|
1719 { |
|
1720 png_bytep sp = row; |
|
1721 png_bytep dp = row; |
|
1722 png_uint_32 i; |
|
1723 png_uint_32 istop = row_info->width * row_info->channels; |
|
1724 |
|
1725 for (i = 0; i<istop; i++, sp += 2, dp++) |
|
1726 { |
|
1727 #if defined(PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED) |
|
1728 /* This does a more accurate scaling of the 16-bit color |
|
1729 * value, rather than a simple low-byte truncation. |
|
1730 * |
|
1731 * What the ideal calculation should be: |
|
1732 * *dp = (((((png_uint_32)(*sp) << 8) | |
|
1733 * (png_uint_32)(*(sp + 1))) * 255 + 127) / (png_uint_32)65535L; |
|
1734 * |
|
1735 * GRR: no, I think this is what it really should be: |
|
1736 * *dp = (((((png_uint_32)(*sp) << 8) | |
|
1737 * (png_uint_32)(*(sp + 1))) + 128L) / (png_uint_32)257L; |
|
1738 * |
|
1739 * GRR: here's the exact calculation with shifts: |
|
1740 * temp = (((png_uint_32)(*sp) << 8) | (png_uint_32)(*(sp + 1))) + 128L; |
|
1741 * *dp = (temp - (temp >> 8)) >> 8; |
|
1742 * |
|
1743 * Approximate calculation with shift/add instead of multiply/divide: |
|
1744 * *dp = ((((png_uint_32)(*sp) << 8) | |
|
1745 * (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8; |
|
1746 * |
|
1747 * What we actually do to avoid extra shifting and conversion: |
|
1748 */ |
|
1749 |
|
1750 *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0); |
|
1751 #else |
|
1752 /* Simply discard the low order byte */ |
|
1753 *dp = *sp; |
|
1754 #endif |
|
1755 } |
|
1756 row_info->bit_depth = 8; |
|
1757 row_info->pixel_depth = (png_byte)(8 * row_info->channels); |
|
1758 row_info->rowbytes = row_info->width * row_info->channels; |
|
1759 } |
|
1760 } |
|
1761 #endif |
|
1762 |
|
1763 #if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) |
|
1764 void /* PRIVATE */ |
|
1765 png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) |
|
1766 { |
|
1767 png_debug(1, "in png_do_read_swap_alpha\n"); |
|
1768 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
1769 if (row != NULL && row_info != NULL) |
|
1770 #endif |
|
1771 { |
|
1772 png_uint_32 row_width = row_info->width; |
|
1773 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
1774 { |
|
1775 /* This converts from RGBA to ARGB */ |
|
1776 if (row_info->bit_depth == 8) |
|
1777 { |
|
1778 png_bytep sp = row + row_info->rowbytes; |
|
1779 png_bytep dp = sp; |
|
1780 png_byte save; |
|
1781 png_uint_32 i; |
|
1782 |
|
1783 for (i = 0; i < row_width; i++) |
|
1784 { |
|
1785 save = *(--sp); |
|
1786 *(--dp) = *(--sp); |
|
1787 *(--dp) = *(--sp); |
|
1788 *(--dp) = *(--sp); |
|
1789 *(--dp) = save; |
|
1790 } |
|
1791 } |
|
1792 /* This converts from RRGGBBAA to AARRGGBB */ |
|
1793 else |
|
1794 { |
|
1795 png_bytep sp = row + row_info->rowbytes; |
|
1796 png_bytep dp = sp; |
|
1797 png_byte save[2]; |
|
1798 png_uint_32 i; |
|
1799 |
|
1800 for (i = 0; i < row_width; i++) |
|
1801 { |
|
1802 save[0] = *(--sp); |
|
1803 save[1] = *(--sp); |
|
1804 *(--dp) = *(--sp); |
|
1805 *(--dp) = *(--sp); |
|
1806 *(--dp) = *(--sp); |
|
1807 *(--dp) = *(--sp); |
|
1808 *(--dp) = *(--sp); |
|
1809 *(--dp) = *(--sp); |
|
1810 *(--dp) = save[0]; |
|
1811 *(--dp) = save[1]; |
|
1812 } |
|
1813 } |
|
1814 } |
|
1815 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
1816 { |
|
1817 /* This converts from GA to AG */ |
|
1818 if (row_info->bit_depth == 8) |
|
1819 { |
|
1820 png_bytep sp = row + row_info->rowbytes; |
|
1821 png_bytep dp = sp; |
|
1822 png_byte save; |
|
1823 png_uint_32 i; |
|
1824 |
|
1825 for (i = 0; i < row_width; i++) |
|
1826 { |
|
1827 save = *(--sp); |
|
1828 *(--dp) = *(--sp); |
|
1829 *(--dp) = save; |
|
1830 } |
|
1831 } |
|
1832 /* This converts from GGAA to AAGG */ |
|
1833 else |
|
1834 { |
|
1835 png_bytep sp = row + row_info->rowbytes; |
|
1836 png_bytep dp = sp; |
|
1837 png_byte save[2]; |
|
1838 png_uint_32 i; |
|
1839 |
|
1840 for (i = 0; i < row_width; i++) |
|
1841 { |
|
1842 save[0] = *(--sp); |
|
1843 save[1] = *(--sp); |
|
1844 *(--dp) = *(--sp); |
|
1845 *(--dp) = *(--sp); |
|
1846 *(--dp) = save[0]; |
|
1847 *(--dp) = save[1]; |
|
1848 } |
|
1849 } |
|
1850 } |
|
1851 } |
|
1852 } |
|
1853 #endif |
|
1854 |
|
1855 #if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) |
|
1856 void /* PRIVATE */ |
|
1857 png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) |
|
1858 { |
|
1859 png_debug(1, "in png_do_read_invert_alpha\n"); |
|
1860 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
1861 if (row != NULL && row_info != NULL) |
|
1862 #endif |
|
1863 { |
|
1864 png_uint_32 row_width = row_info->width; |
|
1865 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
1866 { |
|
1867 /* This inverts the alpha channel in RGBA */ |
|
1868 if (row_info->bit_depth == 8) |
|
1869 { |
|
1870 png_bytep sp = row + row_info->rowbytes; |
|
1871 png_bytep dp = sp; |
|
1872 png_uint_32 i; |
|
1873 |
|
1874 for (i = 0; i < row_width; i++) |
|
1875 { |
|
1876 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1877 |
|
1878 /* This does nothing: |
|
1879 *(--dp) = *(--sp); |
|
1880 *(--dp) = *(--sp); |
|
1881 *(--dp) = *(--sp); |
|
1882 We can replace it with: |
|
1883 */ |
|
1884 sp-=3; |
|
1885 dp=sp; |
|
1886 } |
|
1887 } |
|
1888 /* This inverts the alpha channel in RRGGBBAA */ |
|
1889 else |
|
1890 { |
|
1891 png_bytep sp = row + row_info->rowbytes; |
|
1892 png_bytep dp = sp; |
|
1893 png_uint_32 i; |
|
1894 |
|
1895 for (i = 0; i < row_width; i++) |
|
1896 { |
|
1897 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1898 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1899 |
|
1900 /* This does nothing: |
|
1901 *(--dp) = *(--sp); |
|
1902 *(--dp) = *(--sp); |
|
1903 *(--dp) = *(--sp); |
|
1904 *(--dp) = *(--sp); |
|
1905 *(--dp) = *(--sp); |
|
1906 *(--dp) = *(--sp); |
|
1907 We can replace it with: |
|
1908 */ |
|
1909 sp-=6; |
|
1910 dp=sp; |
|
1911 } |
|
1912 } |
|
1913 } |
|
1914 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
1915 { |
|
1916 /* This inverts the alpha channel in GA */ |
|
1917 if (row_info->bit_depth == 8) |
|
1918 { |
|
1919 png_bytep sp = row + row_info->rowbytes; |
|
1920 png_bytep dp = sp; |
|
1921 png_uint_32 i; |
|
1922 |
|
1923 for (i = 0; i < row_width; i++) |
|
1924 { |
|
1925 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1926 *(--dp) = *(--sp); |
|
1927 } |
|
1928 } |
|
1929 /* This inverts the alpha channel in GGAA */ |
|
1930 else |
|
1931 { |
|
1932 png_bytep sp = row + row_info->rowbytes; |
|
1933 png_bytep dp = sp; |
|
1934 png_uint_32 i; |
|
1935 |
|
1936 for (i = 0; i < row_width; i++) |
|
1937 { |
|
1938 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1939 *(--dp) = (png_byte)(255 - *(--sp)); |
|
1940 /* |
|
1941 *(--dp) = *(--sp); |
|
1942 *(--dp) = *(--sp); |
|
1943 */ |
|
1944 sp-=2; |
|
1945 dp=sp; |
|
1946 } |
|
1947 } |
|
1948 } |
|
1949 } |
|
1950 } |
|
1951 #endif |
|
1952 |
|
1953 #if defined(PNG_READ_FILLER_SUPPORTED) |
|
1954 /* Add filler channel if we have RGB color */ |
|
1955 void /* PRIVATE */ |
|
1956 png_do_read_filler(png_row_infop row_info, png_bytep row, |
|
1957 png_uint_32 filler, png_uint_32 flags) |
|
1958 { |
|
1959 png_uint_32 i; |
|
1960 png_uint_32 row_width = row_info->width; |
|
1961 |
|
1962 png_byte hi_filler = (png_byte)((filler>>8) & 0xff); |
|
1963 png_byte lo_filler = (png_byte)(filler & 0xff); |
|
1964 |
|
1965 png_debug(1, "in png_do_read_filler\n"); |
|
1966 if ( |
|
1967 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
1968 row != NULL && row_info != NULL && |
|
1969 #endif |
|
1970 row_info->color_type == PNG_COLOR_TYPE_GRAY) |
|
1971 { |
|
1972 if (row_info->bit_depth == 8) |
|
1973 { |
|
1974 /* This changes the data from G to GX */ |
|
1975 if (flags & PNG_FLAG_FILLER_AFTER) |
|
1976 { |
|
1977 png_bytep sp = row + (png_size_t)row_width; |
|
1978 png_bytep dp = sp + (png_size_t)row_width; |
|
1979 for (i = 1; i < row_width; i++) |
|
1980 { |
|
1981 *(--dp) = lo_filler; |
|
1982 *(--dp) = *(--sp); |
|
1983 } |
|
1984 *(--dp) = lo_filler; |
|
1985 row_info->channels = 2; |
|
1986 row_info->pixel_depth = 16; |
|
1987 row_info->rowbytes = row_width * 2; |
|
1988 } |
|
1989 /* This changes the data from G to XG */ |
|
1990 else |
|
1991 { |
|
1992 png_bytep sp = row + (png_size_t)row_width; |
|
1993 png_bytep dp = sp + (png_size_t)row_width; |
|
1994 for (i = 0; i < row_width; i++) |
|
1995 { |
|
1996 *(--dp) = *(--sp); |
|
1997 *(--dp) = lo_filler; |
|
1998 } |
|
1999 row_info->channels = 2; |
|
2000 row_info->pixel_depth = 16; |
|
2001 row_info->rowbytes = row_width * 2; |
|
2002 } |
|
2003 } |
|
2004 else if (row_info->bit_depth == 16) |
|
2005 { |
|
2006 /* This changes the data from GG to GGXX */ |
|
2007 if (flags & PNG_FLAG_FILLER_AFTER) |
|
2008 { |
|
2009 png_bytep sp = row + (png_size_t)row_width * 2; |
|
2010 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2011 for (i = 1; i < row_width; i++) |
|
2012 { |
|
2013 *(--dp) = hi_filler; |
|
2014 *(--dp) = lo_filler; |
|
2015 *(--dp) = *(--sp); |
|
2016 *(--dp) = *(--sp); |
|
2017 } |
|
2018 *(--dp) = hi_filler; |
|
2019 *(--dp) = lo_filler; |
|
2020 row_info->channels = 2; |
|
2021 row_info->pixel_depth = 32; |
|
2022 row_info->rowbytes = row_width * 4; |
|
2023 } |
|
2024 /* This changes the data from GG to XXGG */ |
|
2025 else |
|
2026 { |
|
2027 png_bytep sp = row + (png_size_t)row_width * 2; |
|
2028 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2029 for (i = 0; i < row_width; i++) |
|
2030 { |
|
2031 *(--dp) = *(--sp); |
|
2032 *(--dp) = *(--sp); |
|
2033 *(--dp) = hi_filler; |
|
2034 *(--dp) = lo_filler; |
|
2035 } |
|
2036 row_info->channels = 2; |
|
2037 row_info->pixel_depth = 32; |
|
2038 row_info->rowbytes = row_width * 4; |
|
2039 } |
|
2040 } |
|
2041 } /* COLOR_TYPE == GRAY */ |
|
2042 else if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
2043 { |
|
2044 if (row_info->bit_depth == 8) |
|
2045 { |
|
2046 /* This changes the data from RGB to RGBX */ |
|
2047 if (flags & PNG_FLAG_FILLER_AFTER) |
|
2048 { |
|
2049 png_bytep sp = row + (png_size_t)row_width * 3; |
|
2050 png_bytep dp = sp + (png_size_t)row_width; |
|
2051 for (i = 1; i < row_width; i++) |
|
2052 { |
|
2053 *(--dp) = lo_filler; |
|
2054 *(--dp) = *(--sp); |
|
2055 *(--dp) = *(--sp); |
|
2056 *(--dp) = *(--sp); |
|
2057 } |
|
2058 *(--dp) = lo_filler; |
|
2059 row_info->channels = 4; |
|
2060 row_info->pixel_depth = 32; |
|
2061 row_info->rowbytes = row_width * 4; |
|
2062 } |
|
2063 /* This changes the data from RGB to XRGB */ |
|
2064 else |
|
2065 { |
|
2066 png_bytep sp = row + (png_size_t)row_width * 3; |
|
2067 png_bytep dp = sp + (png_size_t)row_width; |
|
2068 for (i = 0; i < row_width; i++) |
|
2069 { |
|
2070 *(--dp) = *(--sp); |
|
2071 *(--dp) = *(--sp); |
|
2072 *(--dp) = *(--sp); |
|
2073 *(--dp) = lo_filler; |
|
2074 } |
|
2075 row_info->channels = 4; |
|
2076 row_info->pixel_depth = 32; |
|
2077 row_info->rowbytes = row_width * 4; |
|
2078 } |
|
2079 } |
|
2080 else if (row_info->bit_depth == 16) |
|
2081 { |
|
2082 /* This changes the data from RRGGBB to RRGGBBXX */ |
|
2083 if (flags & PNG_FLAG_FILLER_AFTER) |
|
2084 { |
|
2085 png_bytep sp = row + (png_size_t)row_width * 6; |
|
2086 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2087 for (i = 1; i < row_width; i++) |
|
2088 { |
|
2089 *(--dp) = hi_filler; |
|
2090 *(--dp) = lo_filler; |
|
2091 *(--dp) = *(--sp); |
|
2092 *(--dp) = *(--sp); |
|
2093 *(--dp) = *(--sp); |
|
2094 *(--dp) = *(--sp); |
|
2095 *(--dp) = *(--sp); |
|
2096 *(--dp) = *(--sp); |
|
2097 } |
|
2098 *(--dp) = hi_filler; |
|
2099 *(--dp) = lo_filler; |
|
2100 row_info->channels = 4; |
|
2101 row_info->pixel_depth = 64; |
|
2102 row_info->rowbytes = row_width * 8; |
|
2103 } |
|
2104 /* This changes the data from RRGGBB to XXRRGGBB */ |
|
2105 else |
|
2106 { |
|
2107 png_bytep sp = row + (png_size_t)row_width * 6; |
|
2108 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2109 for (i = 0; i < row_width; i++) |
|
2110 { |
|
2111 *(--dp) = *(--sp); |
|
2112 *(--dp) = *(--sp); |
|
2113 *(--dp) = *(--sp); |
|
2114 *(--dp) = *(--sp); |
|
2115 *(--dp) = *(--sp); |
|
2116 *(--dp) = *(--sp); |
|
2117 *(--dp) = hi_filler; |
|
2118 *(--dp) = lo_filler; |
|
2119 } |
|
2120 row_info->channels = 4; |
|
2121 row_info->pixel_depth = 64; |
|
2122 row_info->rowbytes = row_width * 8; |
|
2123 } |
|
2124 } |
|
2125 } /* COLOR_TYPE == RGB */ |
|
2126 } |
|
2127 #endif |
|
2128 |
|
2129 #if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) |
|
2130 /* expand grayscale files to RGB, with or without alpha */ |
|
2131 void /* PRIVATE */ |
|
2132 png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) |
|
2133 { |
|
2134 png_uint_32 i; |
|
2135 png_uint_32 row_width = row_info->width; |
|
2136 |
|
2137 png_debug(1, "in png_do_gray_to_rgb\n"); |
|
2138 if (row_info->bit_depth >= 8 && |
|
2139 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
2140 row != NULL && row_info != NULL && |
|
2141 #endif |
|
2142 !(row_info->color_type & PNG_COLOR_MASK_COLOR)) |
|
2143 { |
|
2144 if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
|
2145 { |
|
2146 if (row_info->bit_depth == 8) |
|
2147 { |
|
2148 png_bytep sp = row + (png_size_t)row_width - 1; |
|
2149 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2150 for (i = 0; i < row_width; i++) |
|
2151 { |
|
2152 *(dp--) = *sp; |
|
2153 *(dp--) = *sp; |
|
2154 *(dp--) = *(sp--); |
|
2155 } |
|
2156 } |
|
2157 else |
|
2158 { |
|
2159 png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
|
2160 png_bytep dp = sp + (png_size_t)row_width * 4; |
|
2161 for (i = 0; i < row_width; i++) |
|
2162 { |
|
2163 *(dp--) = *sp; |
|
2164 *(dp--) = *(sp - 1); |
|
2165 *(dp--) = *sp; |
|
2166 *(dp--) = *(sp - 1); |
|
2167 *(dp--) = *(sp--); |
|
2168 *(dp--) = *(sp--); |
|
2169 } |
|
2170 } |
|
2171 } |
|
2172 else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) |
|
2173 { |
|
2174 if (row_info->bit_depth == 8) |
|
2175 { |
|
2176 png_bytep sp = row + (png_size_t)row_width * 2 - 1; |
|
2177 png_bytep dp = sp + (png_size_t)row_width * 2; |
|
2178 for (i = 0; i < row_width; i++) |
|
2179 { |
|
2180 *(dp--) = *(sp--); |
|
2181 *(dp--) = *sp; |
|
2182 *(dp--) = *sp; |
|
2183 *(dp--) = *(sp--); |
|
2184 } |
|
2185 } |
|
2186 else |
|
2187 { |
|
2188 png_bytep sp = row + (png_size_t)row_width * 4 - 1; |
|
2189 png_bytep dp = sp + (png_size_t)row_width * 4; |
|
2190 for (i = 0; i < row_width; i++) |
|
2191 { |
|
2192 *(dp--) = *(sp--); |
|
2193 *(dp--) = *(sp--); |
|
2194 *(dp--) = *sp; |
|
2195 *(dp--) = *(sp - 1); |
|
2196 *(dp--) = *sp; |
|
2197 *(dp--) = *(sp - 1); |
|
2198 *(dp--) = *(sp--); |
|
2199 *(dp--) = *(sp--); |
|
2200 } |
|
2201 } |
|
2202 } |
|
2203 row_info->channels += (png_byte)2; |
|
2204 row_info->color_type |= PNG_COLOR_MASK_COLOR; |
|
2205 row_info->pixel_depth = (png_byte)(row_info->channels * |
|
2206 row_info->bit_depth); |
|
2207 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
2208 } |
|
2209 } |
|
2210 #endif |
|
2211 |
|
2212 #if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
2213 /* reduce RGB files to grayscale, with or without alpha |
|
2214 * using the equation given in Poynton's ColorFAQ at |
|
2215 * <http://www.inforamp.net/~poynton/> (THIS LINK IS DEAD June 2008) |
|
2216 * New link: |
|
2217 * <http://www.poynton.com/notes/colour_and_gamma/> |
|
2218 * Charles Poynton poynton at poynton.com |
|
2219 * |
|
2220 * Y = 0.212671 * R + 0.715160 * G + 0.072169 * B |
|
2221 * |
|
2222 * We approximate this with |
|
2223 * |
|
2224 * Y = 0.21268 * R + 0.7151 * G + 0.07217 * B |
|
2225 * |
|
2226 * which can be expressed with integers as |
|
2227 * |
|
2228 * Y = (6969 * R + 23434 * G + 2365 * B)/32768 |
|
2229 * |
|
2230 * The calculation is to be done in a linear colorspace. |
|
2231 * |
|
2232 * Other integer coefficents can be used via png_set_rgb_to_gray(). |
|
2233 */ |
|
2234 int /* PRIVATE */ |
|
2235 png_do_rgb_to_gray(png_structp png_ptr, png_row_infop row_info, png_bytep row) |
|
2236 |
|
2237 { |
|
2238 png_uint_32 i; |
|
2239 |
|
2240 png_uint_32 row_width = row_info->width; |
|
2241 int rgb_error = 0; |
|
2242 |
|
2243 png_debug(1, "in png_do_rgb_to_gray\n"); |
|
2244 if ( |
|
2245 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
2246 row != NULL && row_info != NULL && |
|
2247 #endif |
|
2248 (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
|
2249 { |
|
2250 png_uint_32 rc = png_ptr->rgb_to_gray_red_coeff; |
|
2251 png_uint_32 gc = png_ptr->rgb_to_gray_green_coeff; |
|
2252 png_uint_32 bc = png_ptr->rgb_to_gray_blue_coeff; |
|
2253 |
|
2254 if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
2255 { |
|
2256 if (row_info->bit_depth == 8) |
|
2257 { |
|
2258 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2259 if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
|
2260 { |
|
2261 png_bytep sp = row; |
|
2262 png_bytep dp = row; |
|
2263 |
|
2264 for (i = 0; i < row_width; i++) |
|
2265 { |
|
2266 png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
|
2267 png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
|
2268 png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
|
2269 if (red != green || red != blue) |
|
2270 { |
|
2271 rgb_error |= 1; |
|
2272 *(dp++) = png_ptr->gamma_from_1[ |
|
2273 (rc*red + gc*green + bc*blue)>>15]; |
|
2274 } |
|
2275 else |
|
2276 *(dp++) = *(sp - 1); |
|
2277 } |
|
2278 } |
|
2279 else |
|
2280 #endif |
|
2281 { |
|
2282 png_bytep sp = row; |
|
2283 png_bytep dp = row; |
|
2284 for (i = 0; i < row_width; i++) |
|
2285 { |
|
2286 png_byte red = *(sp++); |
|
2287 png_byte green = *(sp++); |
|
2288 png_byte blue = *(sp++); |
|
2289 if (red != green || red != blue) |
|
2290 { |
|
2291 rgb_error |= 1; |
|
2292 *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); |
|
2293 } |
|
2294 else |
|
2295 *(dp++) = *(sp - 1); |
|
2296 } |
|
2297 } |
|
2298 } |
|
2299 |
|
2300 else /* RGB bit_depth == 16 */ |
|
2301 { |
|
2302 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2303 if (png_ptr->gamma_16_to_1 != NULL && |
|
2304 png_ptr->gamma_16_from_1 != NULL) |
|
2305 { |
|
2306 png_bytep sp = row; |
|
2307 png_bytep dp = row; |
|
2308 for (i = 0; i < row_width; i++) |
|
2309 { |
|
2310 png_uint_16 red, green, blue, w; |
|
2311 |
|
2312 red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2313 green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2314 blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2315 |
|
2316 if (red == green && red == blue) |
|
2317 w = red; |
|
2318 else |
|
2319 { |
|
2320 png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> |
|
2321 png_ptr->gamma_shift][red>>8]; |
|
2322 png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >> |
|
2323 png_ptr->gamma_shift][green>>8]; |
|
2324 png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> |
|
2325 png_ptr->gamma_shift][blue>>8]; |
|
2326 png_uint_16 gray16 = (png_uint_16)((rc*red_1 + gc*green_1 |
|
2327 + bc*blue_1)>>15); |
|
2328 w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
|
2329 png_ptr->gamma_shift][gray16 >> 8]; |
|
2330 rgb_error |= 1; |
|
2331 } |
|
2332 |
|
2333 *(dp++) = (png_byte)((w>>8) & 0xff); |
|
2334 *(dp++) = (png_byte)(w & 0xff); |
|
2335 } |
|
2336 } |
|
2337 else |
|
2338 #endif |
|
2339 { |
|
2340 png_bytep sp = row; |
|
2341 png_bytep dp = row; |
|
2342 for (i = 0; i < row_width; i++) |
|
2343 { |
|
2344 png_uint_16 red, green, blue, gray16; |
|
2345 |
|
2346 red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2347 green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2348 blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2349 |
|
2350 if (red != green || red != blue) |
|
2351 rgb_error |= 1; |
|
2352 gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); |
|
2353 *(dp++) = (png_byte)((gray16>>8) & 0xff); |
|
2354 *(dp++) = (png_byte)(gray16 & 0xff); |
|
2355 } |
|
2356 } |
|
2357 } |
|
2358 } |
|
2359 if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
2360 { |
|
2361 if (row_info->bit_depth == 8) |
|
2362 { |
|
2363 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2364 if (png_ptr->gamma_from_1 != NULL && png_ptr->gamma_to_1 != NULL) |
|
2365 { |
|
2366 png_bytep sp = row; |
|
2367 png_bytep dp = row; |
|
2368 for (i = 0; i < row_width; i++) |
|
2369 { |
|
2370 png_byte red = png_ptr->gamma_to_1[*(sp++)]; |
|
2371 png_byte green = png_ptr->gamma_to_1[*(sp++)]; |
|
2372 png_byte blue = png_ptr->gamma_to_1[*(sp++)]; |
|
2373 if (red != green || red != blue) |
|
2374 rgb_error |= 1; |
|
2375 *(dp++) = png_ptr->gamma_from_1 |
|
2376 [(rc*red + gc*green + bc*blue)>>15]; |
|
2377 *(dp++) = *(sp++); /* alpha */ |
|
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_byte red = *(sp++); |
|
2388 png_byte green = *(sp++); |
|
2389 png_byte blue = *(sp++); |
|
2390 if (red != green || red != blue) |
|
2391 rgb_error |= 1; |
|
2392 *(dp++) = (png_byte)((rc*red + gc*green + bc*blue)>>15); |
|
2393 *(dp++) = *(sp++); /* alpha */ |
|
2394 } |
|
2395 } |
|
2396 } |
|
2397 else /* RGBA bit_depth == 16 */ |
|
2398 { |
|
2399 #if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2400 if (png_ptr->gamma_16_to_1 != NULL && |
|
2401 png_ptr->gamma_16_from_1 != NULL) |
|
2402 { |
|
2403 png_bytep sp = row; |
|
2404 png_bytep dp = row; |
|
2405 for (i = 0; i < row_width; i++) |
|
2406 { |
|
2407 png_uint_16 red, green, blue, w; |
|
2408 |
|
2409 red = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2410 green = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2411 blue = (png_uint_16)(((*(sp))<<8) | *(sp+1)); sp+=2; |
|
2412 |
|
2413 if (red == green && red == blue) |
|
2414 w = red; |
|
2415 else |
|
2416 { |
|
2417 png_uint_16 red_1 = png_ptr->gamma_16_to_1[(red&0xff) >> |
|
2418 png_ptr->gamma_shift][red>>8]; |
|
2419 png_uint_16 green_1 = png_ptr->gamma_16_to_1[(green&0xff) >> |
|
2420 png_ptr->gamma_shift][green>>8]; |
|
2421 png_uint_16 blue_1 = png_ptr->gamma_16_to_1[(blue&0xff) >> |
|
2422 png_ptr->gamma_shift][blue>>8]; |
|
2423 png_uint_16 gray16 = (png_uint_16)((rc * red_1 |
|
2424 + gc * green_1 + bc * blue_1)>>15); |
|
2425 w = png_ptr->gamma_16_from_1[(gray16&0xff) >> |
|
2426 png_ptr->gamma_shift][gray16 >> 8]; |
|
2427 rgb_error |= 1; |
|
2428 } |
|
2429 |
|
2430 *(dp++) = (png_byte)((w>>8) & 0xff); |
|
2431 *(dp++) = (png_byte)(w & 0xff); |
|
2432 *(dp++) = *(sp++); /* alpha */ |
|
2433 *(dp++) = *(sp++); |
|
2434 } |
|
2435 } |
|
2436 else |
|
2437 #endif |
|
2438 { |
|
2439 png_bytep sp = row; |
|
2440 png_bytep dp = row; |
|
2441 for (i = 0; i < row_width; i++) |
|
2442 { |
|
2443 png_uint_16 red, green, blue, gray16; |
|
2444 red = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
|
2445 green = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
|
2446 blue = (png_uint_16)((*(sp)<<8) | *(sp+1)); sp+=2; |
|
2447 if (red != green || red != blue) |
|
2448 rgb_error |= 1; |
|
2449 gray16 = (png_uint_16)((rc*red + gc*green + bc*blue)>>15); |
|
2450 *(dp++) = (png_byte)((gray16>>8) & 0xff); |
|
2451 *(dp++) = (png_byte)(gray16 & 0xff); |
|
2452 *(dp++) = *(sp++); /* alpha */ |
|
2453 *(dp++) = *(sp++); |
|
2454 } |
|
2455 } |
|
2456 } |
|
2457 } |
|
2458 row_info->channels -= (png_byte)2; |
|
2459 row_info->color_type &= ~PNG_COLOR_MASK_COLOR; |
|
2460 row_info->pixel_depth = (png_byte)(row_info->channels * |
|
2461 row_info->bit_depth); |
|
2462 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
2463 } |
|
2464 return rgb_error; |
|
2465 } |
|
2466 #endif |
|
2467 |
|
2468 /* Build a grayscale palette. Palette is assumed to be 1 << bit_depth |
|
2469 * large of png_color. This lets grayscale images be treated as |
|
2470 * paletted. Most useful for gamma correction and simplification |
|
2471 * of code. |
|
2472 */ |
|
2473 void PNGAPI |
|
2474 png_build_grayscale_palette(int bit_depth, png_colorp palette) |
|
2475 { |
|
2476 int num_palette; |
|
2477 int color_inc; |
|
2478 int i; |
|
2479 int v; |
|
2480 |
|
2481 png_debug(1, "in png_do_build_grayscale_palette\n"); |
|
2482 if (palette == NULL) |
|
2483 return; |
|
2484 |
|
2485 switch (bit_depth) |
|
2486 { |
|
2487 case 1: |
|
2488 num_palette = 2; |
|
2489 color_inc = 0xff; |
|
2490 break; |
|
2491 case 2: |
|
2492 num_palette = 4; |
|
2493 color_inc = 0x55; |
|
2494 break; |
|
2495 case 4: |
|
2496 num_palette = 16; |
|
2497 color_inc = 0x11; |
|
2498 break; |
|
2499 case 8: |
|
2500 num_palette = 256; |
|
2501 color_inc = 1; |
|
2502 break; |
|
2503 default: |
|
2504 num_palette = 0; |
|
2505 color_inc = 0; |
|
2506 break; |
|
2507 } |
|
2508 |
|
2509 for (i = 0, v = 0; i < num_palette; i++, v += color_inc) |
|
2510 { |
|
2511 palette[i].red = (png_byte)v; |
|
2512 palette[i].green = (png_byte)v; |
|
2513 palette[i].blue = (png_byte)v; |
|
2514 } |
|
2515 } |
|
2516 |
|
2517 /* This function is currently unused. Do we really need it? */ |
|
2518 #if defined(PNG_READ_DITHER_SUPPORTED) && defined(PNG_CORRECT_PALETTE_SUPPORTED) |
|
2519 void /* PRIVATE */ |
|
2520 png_correct_palette(png_structp png_ptr, png_colorp palette, |
|
2521 int num_palette) |
|
2522 { |
|
2523 png_debug(1, "in png_correct_palette\n"); |
|
2524 #if defined(PNG_READ_BACKGROUND_SUPPORTED) && \ |
|
2525 defined(PNG_READ_GAMMA_SUPPORTED) && defined(PNG_FLOATING_POINT_SUPPORTED) |
|
2526 if (png_ptr->transformations & (PNG_GAMMA | PNG_BACKGROUND)) |
|
2527 { |
|
2528 png_color back, back_1; |
|
2529 |
|
2530 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) |
|
2531 { |
|
2532 back.red = png_ptr->gamma_table[png_ptr->background.red]; |
|
2533 back.green = png_ptr->gamma_table[png_ptr->background.green]; |
|
2534 back.blue = png_ptr->gamma_table[png_ptr->background.blue]; |
|
2535 |
|
2536 back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; |
|
2537 back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; |
|
2538 back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; |
|
2539 } |
|
2540 else |
|
2541 { |
|
2542 double g; |
|
2543 |
|
2544 g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma); |
|
2545 |
|
2546 if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN || |
|
2547 fabs(g - 1.0) < PNG_GAMMA_THRESHOLD) |
|
2548 { |
|
2549 back.red = png_ptr->background.red; |
|
2550 back.green = png_ptr->background.green; |
|
2551 back.blue = png_ptr->background.blue; |
|
2552 } |
|
2553 else |
|
2554 { |
|
2555 back.red = |
|
2556 (png_byte)(pow((double)png_ptr->background.red/255, g) * |
|
2557 255.0 + 0.5); |
|
2558 back.green = |
|
2559 (png_byte)(pow((double)png_ptr->background.green/255, g) * |
|
2560 255.0 + 0.5); |
|
2561 back.blue = |
|
2562 (png_byte)(pow((double)png_ptr->background.blue/255, g) * |
|
2563 255.0 + 0.5); |
|
2564 } |
|
2565 |
|
2566 g = 1.0 / png_ptr->background_gamma; |
|
2567 |
|
2568 back_1.red = |
|
2569 (png_byte)(pow((double)png_ptr->background.red/255, g) * |
|
2570 255.0 + 0.5); |
|
2571 back_1.green = |
|
2572 (png_byte)(pow((double)png_ptr->background.green/255, g) * |
|
2573 255.0 + 0.5); |
|
2574 back_1.blue = |
|
2575 (png_byte)(pow((double)png_ptr->background.blue/255, g) * |
|
2576 255.0 + 0.5); |
|
2577 } |
|
2578 |
|
2579 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
2580 { |
|
2581 png_uint_32 i; |
|
2582 |
|
2583 for (i = 0; i < (png_uint_32)num_palette; i++) |
|
2584 { |
|
2585 if (i < png_ptr->num_trans && png_ptr->trans[i] == 0) |
|
2586 { |
|
2587 palette[i] = back; |
|
2588 } |
|
2589 else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff) |
|
2590 { |
|
2591 png_byte v, w; |
|
2592 |
|
2593 v = png_ptr->gamma_to_1[png_ptr->palette[i].red]; |
|
2594 png_composite(w, v, png_ptr->trans[i], back_1.red); |
|
2595 palette[i].red = png_ptr->gamma_from_1[w]; |
|
2596 |
|
2597 v = png_ptr->gamma_to_1[png_ptr->palette[i].green]; |
|
2598 png_composite(w, v, png_ptr->trans[i], back_1.green); |
|
2599 palette[i].green = png_ptr->gamma_from_1[w]; |
|
2600 |
|
2601 v = png_ptr->gamma_to_1[png_ptr->palette[i].blue]; |
|
2602 png_composite(w, v, png_ptr->trans[i], back_1.blue); |
|
2603 palette[i].blue = png_ptr->gamma_from_1[w]; |
|
2604 } |
|
2605 else |
|
2606 { |
|
2607 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
2608 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
2609 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
2610 } |
|
2611 } |
|
2612 } |
|
2613 else |
|
2614 { |
|
2615 int i; |
|
2616 |
|
2617 for (i = 0; i < num_palette; i++) |
|
2618 { |
|
2619 if (palette[i].red == (png_byte)png_ptr->trans_values.gray) |
|
2620 { |
|
2621 palette[i] = back; |
|
2622 } |
|
2623 else |
|
2624 { |
|
2625 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
2626 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
2627 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
2628 } |
|
2629 } |
|
2630 } |
|
2631 } |
|
2632 else |
|
2633 #endif |
|
2634 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2635 if (png_ptr->transformations & PNG_GAMMA) |
|
2636 { |
|
2637 int i; |
|
2638 |
|
2639 for (i = 0; i < num_palette; i++) |
|
2640 { |
|
2641 palette[i].red = png_ptr->gamma_table[palette[i].red]; |
|
2642 palette[i].green = png_ptr->gamma_table[palette[i].green]; |
|
2643 palette[i].blue = png_ptr->gamma_table[palette[i].blue]; |
|
2644 } |
|
2645 } |
|
2646 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2647 else |
|
2648 #endif |
|
2649 #endif |
|
2650 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2651 if (png_ptr->transformations & PNG_BACKGROUND) |
|
2652 { |
|
2653 if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) |
|
2654 { |
|
2655 png_color back; |
|
2656 |
|
2657 back.red = (png_byte)png_ptr->background.red; |
|
2658 back.green = (png_byte)png_ptr->background.green; |
|
2659 back.blue = (png_byte)png_ptr->background.blue; |
|
2660 |
|
2661 for (i = 0; i < (int)png_ptr->num_trans; i++) |
|
2662 { |
|
2663 if (png_ptr->trans[i] == 0) |
|
2664 { |
|
2665 palette[i].red = back.red; |
|
2666 palette[i].green = back.green; |
|
2667 palette[i].blue = back.blue; |
|
2668 } |
|
2669 else if (png_ptr->trans[i] != 0xff) |
|
2670 { |
|
2671 png_composite(palette[i].red, png_ptr->palette[i].red, |
|
2672 png_ptr->trans[i], back.red); |
|
2673 png_composite(palette[i].green, png_ptr->palette[i].green, |
|
2674 png_ptr->trans[i], back.green); |
|
2675 png_composite(palette[i].blue, png_ptr->palette[i].blue, |
|
2676 png_ptr->trans[i], back.blue); |
|
2677 } |
|
2678 } |
|
2679 } |
|
2680 else /* assume grayscale palette (what else could it be?) */ |
|
2681 { |
|
2682 int i; |
|
2683 |
|
2684 for (i = 0; i < num_palette; i++) |
|
2685 { |
|
2686 if (i == (png_byte)png_ptr->trans_values.gray) |
|
2687 { |
|
2688 palette[i].red = (png_byte)png_ptr->background.red; |
|
2689 palette[i].green = (png_byte)png_ptr->background.green; |
|
2690 palette[i].blue = (png_byte)png_ptr->background.blue; |
|
2691 } |
|
2692 } |
|
2693 } |
|
2694 } |
|
2695 #endif |
|
2696 } |
|
2697 #endif |
|
2698 |
|
2699 #if defined(PNG_READ_BACKGROUND_SUPPORTED) |
|
2700 /* Replace any alpha or transparency with the supplied background color. |
|
2701 * "background" is already in the screen gamma, while "background_1" is |
|
2702 * at a gamma of 1.0. Paletted files have already been taken care of. |
|
2703 */ |
|
2704 void /* PRIVATE */ |
|
2705 png_do_background(png_row_infop row_info, png_bytep row, |
|
2706 png_color_16p trans_values, png_color_16p background |
|
2707 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2708 , png_color_16p background_1, |
|
2709 png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1, |
|
2710 png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1, |
|
2711 png_uint_16pp gamma_16_to_1, int gamma_shift |
|
2712 #endif |
|
2713 ) |
|
2714 { |
|
2715 png_bytep sp, dp; |
|
2716 png_uint_32 i; |
|
2717 png_uint_32 row_width=row_info->width; |
|
2718 int shift; |
|
2719 |
|
2720 png_debug(1, "in png_do_background\n"); |
|
2721 if (background != NULL && |
|
2722 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
2723 row != NULL && row_info != NULL && |
|
2724 #endif |
|
2725 (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) || |
|
2726 (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values))) |
|
2727 { |
|
2728 switch (row_info->color_type) |
|
2729 { |
|
2730 case PNG_COLOR_TYPE_GRAY: |
|
2731 { |
|
2732 switch (row_info->bit_depth) |
|
2733 { |
|
2734 case 1: |
|
2735 { |
|
2736 sp = row; |
|
2737 shift = 7; |
|
2738 for (i = 0; i < row_width; i++) |
|
2739 { |
|
2740 if ((png_uint_16)((*sp >> shift) & 0x01) |
|
2741 == trans_values->gray) |
|
2742 { |
|
2743 *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); |
|
2744 *sp |= (png_byte)(background->gray << shift); |
|
2745 } |
|
2746 if (!shift) |
|
2747 { |
|
2748 shift = 7; |
|
2749 sp++; |
|
2750 } |
|
2751 else |
|
2752 shift--; |
|
2753 } |
|
2754 break; |
|
2755 } |
|
2756 case 2: |
|
2757 { |
|
2758 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2759 if (gamma_table != NULL) |
|
2760 { |
|
2761 sp = row; |
|
2762 shift = 6; |
|
2763 for (i = 0; i < row_width; i++) |
|
2764 { |
|
2765 if ((png_uint_16)((*sp >> shift) & 0x03) |
|
2766 == trans_values->gray) |
|
2767 { |
|
2768 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
|
2769 *sp |= (png_byte)(background->gray << shift); |
|
2770 } |
|
2771 else |
|
2772 { |
|
2773 png_byte p = (png_byte)((*sp >> shift) & 0x03); |
|
2774 png_byte g = (png_byte)((gamma_table [p | (p << 2) | |
|
2775 (p << 4) | (p << 6)] >> 6) & 0x03); |
|
2776 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
|
2777 *sp |= (png_byte)(g << shift); |
|
2778 } |
|
2779 if (!shift) |
|
2780 { |
|
2781 shift = 6; |
|
2782 sp++; |
|
2783 } |
|
2784 else |
|
2785 shift -= 2; |
|
2786 } |
|
2787 } |
|
2788 else |
|
2789 #endif |
|
2790 { |
|
2791 sp = row; |
|
2792 shift = 6; |
|
2793 for (i = 0; i < row_width; i++) |
|
2794 { |
|
2795 if ((png_uint_16)((*sp >> shift) & 0x03) |
|
2796 == trans_values->gray) |
|
2797 { |
|
2798 *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); |
|
2799 *sp |= (png_byte)(background->gray << shift); |
|
2800 } |
|
2801 if (!shift) |
|
2802 { |
|
2803 shift = 6; |
|
2804 sp++; |
|
2805 } |
|
2806 else |
|
2807 shift -= 2; |
|
2808 } |
|
2809 } |
|
2810 break; |
|
2811 } |
|
2812 case 4: |
|
2813 { |
|
2814 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2815 if (gamma_table != NULL) |
|
2816 { |
|
2817 sp = row; |
|
2818 shift = 4; |
|
2819 for (i = 0; i < row_width; i++) |
|
2820 { |
|
2821 if ((png_uint_16)((*sp >> shift) & 0x0f) |
|
2822 == trans_values->gray) |
|
2823 { |
|
2824 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
|
2825 *sp |= (png_byte)(background->gray << shift); |
|
2826 } |
|
2827 else |
|
2828 { |
|
2829 png_byte p = (png_byte)((*sp >> shift) & 0x0f); |
|
2830 png_byte g = (png_byte)((gamma_table[p | |
|
2831 (p << 4)] >> 4) & 0x0f); |
|
2832 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
|
2833 *sp |= (png_byte)(g << shift); |
|
2834 } |
|
2835 if (!shift) |
|
2836 { |
|
2837 shift = 4; |
|
2838 sp++; |
|
2839 } |
|
2840 else |
|
2841 shift -= 4; |
|
2842 } |
|
2843 } |
|
2844 else |
|
2845 #endif |
|
2846 { |
|
2847 sp = row; |
|
2848 shift = 4; |
|
2849 for (i = 0; i < row_width; i++) |
|
2850 { |
|
2851 if ((png_uint_16)((*sp >> shift) & 0x0f) |
|
2852 == trans_values->gray) |
|
2853 { |
|
2854 *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); |
|
2855 *sp |= (png_byte)(background->gray << shift); |
|
2856 } |
|
2857 if (!shift) |
|
2858 { |
|
2859 shift = 4; |
|
2860 sp++; |
|
2861 } |
|
2862 else |
|
2863 shift -= 4; |
|
2864 } |
|
2865 } |
|
2866 break; |
|
2867 } |
|
2868 case 8: |
|
2869 { |
|
2870 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2871 if (gamma_table != NULL) |
|
2872 { |
|
2873 sp = row; |
|
2874 for (i = 0; i < row_width; i++, sp++) |
|
2875 { |
|
2876 if (*sp == trans_values->gray) |
|
2877 { |
|
2878 *sp = (png_byte)background->gray; |
|
2879 } |
|
2880 else |
|
2881 { |
|
2882 *sp = gamma_table[*sp]; |
|
2883 } |
|
2884 } |
|
2885 } |
|
2886 else |
|
2887 #endif |
|
2888 { |
|
2889 sp = row; |
|
2890 for (i = 0; i < row_width; i++, sp++) |
|
2891 { |
|
2892 if (*sp == trans_values->gray) |
|
2893 { |
|
2894 *sp = (png_byte)background->gray; |
|
2895 } |
|
2896 } |
|
2897 } |
|
2898 break; |
|
2899 } |
|
2900 case 16: |
|
2901 { |
|
2902 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2903 if (gamma_16 != NULL) |
|
2904 { |
|
2905 sp = row; |
|
2906 for (i = 0; i < row_width; i++, sp += 2) |
|
2907 { |
|
2908 png_uint_16 v; |
|
2909 |
|
2910 v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
2911 if (v == trans_values->gray) |
|
2912 { |
|
2913 /* background is already in screen gamma */ |
|
2914 *sp = (png_byte)((background->gray >> 8) & 0xff); |
|
2915 *(sp + 1) = (png_byte)(background->gray & 0xff); |
|
2916 } |
|
2917 else |
|
2918 { |
|
2919 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
2920 *sp = (png_byte)((v >> 8) & 0xff); |
|
2921 *(sp + 1) = (png_byte)(v & 0xff); |
|
2922 } |
|
2923 } |
|
2924 } |
|
2925 else |
|
2926 #endif |
|
2927 { |
|
2928 sp = row; |
|
2929 for (i = 0; i < row_width; i++, sp += 2) |
|
2930 { |
|
2931 png_uint_16 v; |
|
2932 |
|
2933 v = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
2934 if (v == trans_values->gray) |
|
2935 { |
|
2936 *sp = (png_byte)((background->gray >> 8) & 0xff); |
|
2937 *(sp + 1) = (png_byte)(background->gray & 0xff); |
|
2938 } |
|
2939 } |
|
2940 } |
|
2941 break; |
|
2942 } |
|
2943 } |
|
2944 break; |
|
2945 } |
|
2946 case PNG_COLOR_TYPE_RGB: |
|
2947 { |
|
2948 if (row_info->bit_depth == 8) |
|
2949 { |
|
2950 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2951 if (gamma_table != NULL) |
|
2952 { |
|
2953 sp = row; |
|
2954 for (i = 0; i < row_width; i++, sp += 3) |
|
2955 { |
|
2956 if (*sp == trans_values->red && |
|
2957 *(sp + 1) == trans_values->green && |
|
2958 *(sp + 2) == trans_values->blue) |
|
2959 { |
|
2960 *sp = (png_byte)background->red; |
|
2961 *(sp + 1) = (png_byte)background->green; |
|
2962 *(sp + 2) = (png_byte)background->blue; |
|
2963 } |
|
2964 else |
|
2965 { |
|
2966 *sp = gamma_table[*sp]; |
|
2967 *(sp + 1) = gamma_table[*(sp + 1)]; |
|
2968 *(sp + 2) = gamma_table[*(sp + 2)]; |
|
2969 } |
|
2970 } |
|
2971 } |
|
2972 else |
|
2973 #endif |
|
2974 { |
|
2975 sp = row; |
|
2976 for (i = 0; i < row_width; i++, sp += 3) |
|
2977 { |
|
2978 if (*sp == trans_values->red && |
|
2979 *(sp + 1) == trans_values->green && |
|
2980 *(sp + 2) == trans_values->blue) |
|
2981 { |
|
2982 *sp = (png_byte)background->red; |
|
2983 *(sp + 1) = (png_byte)background->green; |
|
2984 *(sp + 2) = (png_byte)background->blue; |
|
2985 } |
|
2986 } |
|
2987 } |
|
2988 } |
|
2989 else /* if (row_info->bit_depth == 16) */ |
|
2990 { |
|
2991 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
2992 if (gamma_16 != NULL) |
|
2993 { |
|
2994 sp = row; |
|
2995 for (i = 0; i < row_width; i++, sp += 6) |
|
2996 { |
|
2997 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
2998 png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
|
2999 png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5)); |
|
3000 if (r == trans_values->red && g == trans_values->green && |
|
3001 b == trans_values->blue) |
|
3002 { |
|
3003 /* background is already in screen gamma */ |
|
3004 *sp = (png_byte)((background->red >> 8) & 0xff); |
|
3005 *(sp + 1) = (png_byte)(background->red & 0xff); |
|
3006 *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); |
|
3007 *(sp + 3) = (png_byte)(background->green & 0xff); |
|
3008 *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
|
3009 *(sp + 5) = (png_byte)(background->blue & 0xff); |
|
3010 } |
|
3011 else |
|
3012 { |
|
3013 png_uint_16 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
3014 *sp = (png_byte)((v >> 8) & 0xff); |
|
3015 *(sp + 1) = (png_byte)(v & 0xff); |
|
3016 v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
|
3017 *(sp + 2) = (png_byte)((v >> 8) & 0xff); |
|
3018 *(sp + 3) = (png_byte)(v & 0xff); |
|
3019 v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
|
3020 *(sp + 4) = (png_byte)((v >> 8) & 0xff); |
|
3021 *(sp + 5) = (png_byte)(v & 0xff); |
|
3022 } |
|
3023 } |
|
3024 } |
|
3025 else |
|
3026 #endif |
|
3027 { |
|
3028 sp = row; |
|
3029 for (i = 0; i < row_width; i++, sp += 6) |
|
3030 { |
|
3031 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp+1)); |
|
3032 png_uint_16 g = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
|
3033 png_uint_16 b = (png_uint_16)(((*(sp+4)) << 8) + *(sp+5)); |
|
3034 |
|
3035 if (r == trans_values->red && g == trans_values->green && |
|
3036 b == trans_values->blue) |
|
3037 { |
|
3038 *sp = (png_byte)((background->red >> 8) & 0xff); |
|
3039 *(sp + 1) = (png_byte)(background->red & 0xff); |
|
3040 *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); |
|
3041 *(sp + 3) = (png_byte)(background->green & 0xff); |
|
3042 *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
|
3043 *(sp + 5) = (png_byte)(background->blue & 0xff); |
|
3044 } |
|
3045 } |
|
3046 } |
|
3047 } |
|
3048 break; |
|
3049 } |
|
3050 case PNG_COLOR_TYPE_GRAY_ALPHA: |
|
3051 { |
|
3052 if (row_info->bit_depth == 8) |
|
3053 { |
|
3054 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3055 if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
|
3056 gamma_table != NULL) |
|
3057 { |
|
3058 sp = row; |
|
3059 dp = row; |
|
3060 for (i = 0; i < row_width; i++, sp += 2, dp++) |
|
3061 { |
|
3062 png_uint_16 a = *(sp + 1); |
|
3063 |
|
3064 if (a == 0xff) |
|
3065 { |
|
3066 *dp = gamma_table[*sp]; |
|
3067 } |
|
3068 else if (a == 0) |
|
3069 { |
|
3070 /* background is already in screen gamma */ |
|
3071 *dp = (png_byte)background->gray; |
|
3072 } |
|
3073 else |
|
3074 { |
|
3075 png_byte v, w; |
|
3076 |
|
3077 v = gamma_to_1[*sp]; |
|
3078 png_composite(w, v, a, background_1->gray); |
|
3079 *dp = gamma_from_1[w]; |
|
3080 } |
|
3081 } |
|
3082 } |
|
3083 else |
|
3084 #endif |
|
3085 { |
|
3086 sp = row; |
|
3087 dp = row; |
|
3088 for (i = 0; i < row_width; i++, sp += 2, dp++) |
|
3089 { |
|
3090 png_byte a = *(sp + 1); |
|
3091 |
|
3092 if (a == 0xff) |
|
3093 { |
|
3094 *dp = *sp; |
|
3095 } |
|
3096 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3097 else if (a == 0) |
|
3098 { |
|
3099 *dp = (png_byte)background->gray; |
|
3100 } |
|
3101 else |
|
3102 { |
|
3103 png_composite(*dp, *sp, a, background_1->gray); |
|
3104 } |
|
3105 #else |
|
3106 *dp = (png_byte)background->gray; |
|
3107 #endif |
|
3108 } |
|
3109 } |
|
3110 } |
|
3111 else /* if (png_ptr->bit_depth == 16) */ |
|
3112 { |
|
3113 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3114 if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
|
3115 gamma_16_to_1 != NULL) |
|
3116 { |
|
3117 sp = row; |
|
3118 dp = row; |
|
3119 for (i = 0; i < row_width; i++, sp += 4, dp += 2) |
|
3120 { |
|
3121 png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
|
3122 |
|
3123 if (a == (png_uint_16)0xffff) |
|
3124 { |
|
3125 png_uint_16 v; |
|
3126 |
|
3127 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
3128 *dp = (png_byte)((v >> 8) & 0xff); |
|
3129 *(dp + 1) = (png_byte)(v & 0xff); |
|
3130 } |
|
3131 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3132 else if (a == 0) |
|
3133 #else |
|
3134 else |
|
3135 #endif |
|
3136 { |
|
3137 /* background is already in screen gamma */ |
|
3138 *dp = (png_byte)((background->gray >> 8) & 0xff); |
|
3139 *(dp + 1) = (png_byte)(background->gray & 0xff); |
|
3140 } |
|
3141 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3142 else |
|
3143 { |
|
3144 png_uint_16 g, v, w; |
|
3145 |
|
3146 g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
|
3147 png_composite_16(v, g, a, background_1->gray); |
|
3148 w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; |
|
3149 *dp = (png_byte)((w >> 8) & 0xff); |
|
3150 *(dp + 1) = (png_byte)(w & 0xff); |
|
3151 } |
|
3152 #endif |
|
3153 } |
|
3154 } |
|
3155 else |
|
3156 #endif |
|
3157 { |
|
3158 sp = row; |
|
3159 dp = row; |
|
3160 for (i = 0; i < row_width; i++, sp += 4, dp += 2) |
|
3161 { |
|
3162 png_uint_16 a = (png_uint_16)(((*(sp+2)) << 8) + *(sp+3)); |
|
3163 if (a == (png_uint_16)0xffff) |
|
3164 { |
|
3165 png_memcpy(dp, sp, 2); |
|
3166 } |
|
3167 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3168 else if (a == 0) |
|
3169 #else |
|
3170 else |
|
3171 #endif |
|
3172 { |
|
3173 *dp = (png_byte)((background->gray >> 8) & 0xff); |
|
3174 *(dp + 1) = (png_byte)(background->gray & 0xff); |
|
3175 } |
|
3176 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3177 else |
|
3178 { |
|
3179 png_uint_16 g, v; |
|
3180 |
|
3181 g = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
3182 png_composite_16(v, g, a, background_1->gray); |
|
3183 *dp = (png_byte)((v >> 8) & 0xff); |
|
3184 *(dp + 1) = (png_byte)(v & 0xff); |
|
3185 } |
|
3186 #endif |
|
3187 } |
|
3188 } |
|
3189 } |
|
3190 break; |
|
3191 } |
|
3192 case PNG_COLOR_TYPE_RGB_ALPHA: |
|
3193 { |
|
3194 if (row_info->bit_depth == 8) |
|
3195 { |
|
3196 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3197 if (gamma_to_1 != NULL && gamma_from_1 != NULL && |
|
3198 gamma_table != NULL) |
|
3199 { |
|
3200 sp = row; |
|
3201 dp = row; |
|
3202 for (i = 0; i < row_width; i++, sp += 4, dp += 3) |
|
3203 { |
|
3204 png_byte a = *(sp + 3); |
|
3205 |
|
3206 if (a == 0xff) |
|
3207 { |
|
3208 *dp = gamma_table[*sp]; |
|
3209 *(dp + 1) = gamma_table[*(sp + 1)]; |
|
3210 *(dp + 2) = gamma_table[*(sp + 2)]; |
|
3211 } |
|
3212 else if (a == 0) |
|
3213 { |
|
3214 /* background is already in screen gamma */ |
|
3215 *dp = (png_byte)background->red; |
|
3216 *(dp + 1) = (png_byte)background->green; |
|
3217 *(dp + 2) = (png_byte)background->blue; |
|
3218 } |
|
3219 else |
|
3220 { |
|
3221 png_byte v, w; |
|
3222 |
|
3223 v = gamma_to_1[*sp]; |
|
3224 png_composite(w, v, a, background_1->red); |
|
3225 *dp = gamma_from_1[w]; |
|
3226 v = gamma_to_1[*(sp + 1)]; |
|
3227 png_composite(w, v, a, background_1->green); |
|
3228 *(dp + 1) = gamma_from_1[w]; |
|
3229 v = gamma_to_1[*(sp + 2)]; |
|
3230 png_composite(w, v, a, background_1->blue); |
|
3231 *(dp + 2) = gamma_from_1[w]; |
|
3232 } |
|
3233 } |
|
3234 } |
|
3235 else |
|
3236 #endif |
|
3237 { |
|
3238 sp = row; |
|
3239 dp = row; |
|
3240 for (i = 0; i < row_width; i++, sp += 4, dp += 3) |
|
3241 { |
|
3242 png_byte a = *(sp + 3); |
|
3243 |
|
3244 if (a == 0xff) |
|
3245 { |
|
3246 *dp = *sp; |
|
3247 *(dp + 1) = *(sp + 1); |
|
3248 *(dp + 2) = *(sp + 2); |
|
3249 } |
|
3250 else if (a == 0) |
|
3251 { |
|
3252 *dp = (png_byte)background->red; |
|
3253 *(dp + 1) = (png_byte)background->green; |
|
3254 *(dp + 2) = (png_byte)background->blue; |
|
3255 } |
|
3256 else |
|
3257 { |
|
3258 png_composite(*dp, *sp, a, background->red); |
|
3259 png_composite(*(dp + 1), *(sp + 1), a, |
|
3260 background->green); |
|
3261 png_composite(*(dp + 2), *(sp + 2), a, |
|
3262 background->blue); |
|
3263 } |
|
3264 } |
|
3265 } |
|
3266 } |
|
3267 else /* if (row_info->bit_depth == 16) */ |
|
3268 { |
|
3269 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3270 if (gamma_16 != NULL && gamma_16_from_1 != NULL && |
|
3271 gamma_16_to_1 != NULL) |
|
3272 { |
|
3273 sp = row; |
|
3274 dp = row; |
|
3275 for (i = 0; i < row_width; i++, sp += 8, dp += 6) |
|
3276 { |
|
3277 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
|
3278 << 8) + (png_uint_16)(*(sp + 7))); |
|
3279 if (a == (png_uint_16)0xffff) |
|
3280 { |
|
3281 png_uint_16 v; |
|
3282 |
|
3283 v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; |
|
3284 *dp = (png_byte)((v >> 8) & 0xff); |
|
3285 *(dp + 1) = (png_byte)(v & 0xff); |
|
3286 v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
|
3287 *(dp + 2) = (png_byte)((v >> 8) & 0xff); |
|
3288 *(dp + 3) = (png_byte)(v & 0xff); |
|
3289 v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
|
3290 *(dp + 4) = (png_byte)((v >> 8) & 0xff); |
|
3291 *(dp + 5) = (png_byte)(v & 0xff); |
|
3292 } |
|
3293 else if (a == 0) |
|
3294 { |
|
3295 /* background is already in screen gamma */ |
|
3296 *dp = (png_byte)((background->red >> 8) & 0xff); |
|
3297 *(dp + 1) = (png_byte)(background->red & 0xff); |
|
3298 *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); |
|
3299 *(dp + 3) = (png_byte)(background->green & 0xff); |
|
3300 *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
|
3301 *(dp + 5) = (png_byte)(background->blue & 0xff); |
|
3302 } |
|
3303 else |
|
3304 { |
|
3305 png_uint_16 v, w, x; |
|
3306 |
|
3307 v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; |
|
3308 png_composite_16(w, v, a, background_1->red); |
|
3309 x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; |
|
3310 *dp = (png_byte)((x >> 8) & 0xff); |
|
3311 *(dp + 1) = (png_byte)(x & 0xff); |
|
3312 v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; |
|
3313 png_composite_16(w, v, a, background_1->green); |
|
3314 x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; |
|
3315 *(dp + 2) = (png_byte)((x >> 8) & 0xff); |
|
3316 *(dp + 3) = (png_byte)(x & 0xff); |
|
3317 v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; |
|
3318 png_composite_16(w, v, a, background_1->blue); |
|
3319 x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8]; |
|
3320 *(dp + 4) = (png_byte)((x >> 8) & 0xff); |
|
3321 *(dp + 5) = (png_byte)(x & 0xff); |
|
3322 } |
|
3323 } |
|
3324 } |
|
3325 else |
|
3326 #endif |
|
3327 { |
|
3328 sp = row; |
|
3329 dp = row; |
|
3330 for (i = 0; i < row_width; i++, sp += 8, dp += 6) |
|
3331 { |
|
3332 png_uint_16 a = (png_uint_16)(((png_uint_16)(*(sp + 6)) |
|
3333 << 8) + (png_uint_16)(*(sp + 7))); |
|
3334 if (a == (png_uint_16)0xffff) |
|
3335 { |
|
3336 png_memcpy(dp, sp, 6); |
|
3337 } |
|
3338 else if (a == 0) |
|
3339 { |
|
3340 *dp = (png_byte)((background->red >> 8) & 0xff); |
|
3341 *(dp + 1) = (png_byte)(background->red & 0xff); |
|
3342 *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); |
|
3343 *(dp + 3) = (png_byte)(background->green & 0xff); |
|
3344 *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); |
|
3345 *(dp + 5) = (png_byte)(background->blue & 0xff); |
|
3346 } |
|
3347 else |
|
3348 { |
|
3349 png_uint_16 v; |
|
3350 |
|
3351 png_uint_16 r = (png_uint_16)(((*sp) << 8) + *(sp + 1)); |
|
3352 png_uint_16 g = (png_uint_16)(((*(sp + 2)) << 8) |
|
3353 + *(sp + 3)); |
|
3354 png_uint_16 b = (png_uint_16)(((*(sp + 4)) << 8) |
|
3355 + *(sp + 5)); |
|
3356 |
|
3357 png_composite_16(v, r, a, background->red); |
|
3358 *dp = (png_byte)((v >> 8) & 0xff); |
|
3359 *(dp + 1) = (png_byte)(v & 0xff); |
|
3360 png_composite_16(v, g, a, background->green); |
|
3361 *(dp + 2) = (png_byte)((v >> 8) & 0xff); |
|
3362 *(dp + 3) = (png_byte)(v & 0xff); |
|
3363 png_composite_16(v, b, a, background->blue); |
|
3364 *(dp + 4) = (png_byte)((v >> 8) & 0xff); |
|
3365 *(dp + 5) = (png_byte)(v & 0xff); |
|
3366 } |
|
3367 } |
|
3368 } |
|
3369 } |
|
3370 break; |
|
3371 } |
|
3372 } |
|
3373 |
|
3374 if (row_info->color_type & PNG_COLOR_MASK_ALPHA) |
|
3375 { |
|
3376 row_info->color_type &= ~PNG_COLOR_MASK_ALPHA; |
|
3377 row_info->channels--; |
|
3378 row_info->pixel_depth = (png_byte)(row_info->channels * |
|
3379 row_info->bit_depth); |
|
3380 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
3381 } |
|
3382 } |
|
3383 } |
|
3384 #endif |
|
3385 |
|
3386 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
3387 /* Gamma correct the image, avoiding the alpha channel. Make sure |
|
3388 * you do this after you deal with the transparency issue on grayscale |
|
3389 * or RGB images. If your bit depth is 8, use gamma_table, if it |
|
3390 * is 16, use gamma_16_table and gamma_shift. Build these with |
|
3391 * build_gamma_table(). |
|
3392 */ |
|
3393 void /* PRIVATE */ |
|
3394 png_do_gamma(png_row_infop row_info, png_bytep row, |
|
3395 png_bytep gamma_table, png_uint_16pp gamma_16_table, |
|
3396 int gamma_shift) |
|
3397 { |
|
3398 png_bytep sp; |
|
3399 png_uint_32 i; |
|
3400 png_uint_32 row_width=row_info->width; |
|
3401 |
|
3402 png_debug(1, "in png_do_gamma\n"); |
|
3403 if ( |
|
3404 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
3405 row != NULL && row_info != NULL && |
|
3406 #endif |
|
3407 ((row_info->bit_depth <= 8 && gamma_table != NULL) || |
|
3408 (row_info->bit_depth == 16 && gamma_16_table != NULL))) |
|
3409 { |
|
3410 switch (row_info->color_type) |
|
3411 { |
|
3412 case PNG_COLOR_TYPE_RGB: |
|
3413 { |
|
3414 if (row_info->bit_depth == 8) |
|
3415 { |
|
3416 sp = row; |
|
3417 for (i = 0; i < row_width; i++) |
|
3418 { |
|
3419 *sp = gamma_table[*sp]; |
|
3420 sp++; |
|
3421 *sp = gamma_table[*sp]; |
|
3422 sp++; |
|
3423 *sp = gamma_table[*sp]; |
|
3424 sp++; |
|
3425 } |
|
3426 } |
|
3427 else /* if (row_info->bit_depth == 16) */ |
|
3428 { |
|
3429 sp = row; |
|
3430 for (i = 0; i < row_width; i++) |
|
3431 { |
|
3432 png_uint_16 v; |
|
3433 |
|
3434 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3435 *sp = (png_byte)((v >> 8) & 0xff); |
|
3436 *(sp + 1) = (png_byte)(v & 0xff); |
|
3437 sp += 2; |
|
3438 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3439 *sp = (png_byte)((v >> 8) & 0xff); |
|
3440 *(sp + 1) = (png_byte)(v & 0xff); |
|
3441 sp += 2; |
|
3442 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3443 *sp = (png_byte)((v >> 8) & 0xff); |
|
3444 *(sp + 1) = (png_byte)(v & 0xff); |
|
3445 sp += 2; |
|
3446 } |
|
3447 } |
|
3448 break; |
|
3449 } |
|
3450 case PNG_COLOR_TYPE_RGB_ALPHA: |
|
3451 { |
|
3452 if (row_info->bit_depth == 8) |
|
3453 { |
|
3454 sp = row; |
|
3455 for (i = 0; i < row_width; i++) |
|
3456 { |
|
3457 *sp = gamma_table[*sp]; |
|
3458 sp++; |
|
3459 *sp = gamma_table[*sp]; |
|
3460 sp++; |
|
3461 *sp = gamma_table[*sp]; |
|
3462 sp++; |
|
3463 sp++; |
|
3464 } |
|
3465 } |
|
3466 else /* if (row_info->bit_depth == 16) */ |
|
3467 { |
|
3468 sp = row; |
|
3469 for (i = 0; i < row_width; i++) |
|
3470 { |
|
3471 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3472 *sp = (png_byte)((v >> 8) & 0xff); |
|
3473 *(sp + 1) = (png_byte)(v & 0xff); |
|
3474 sp += 2; |
|
3475 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3476 *sp = (png_byte)((v >> 8) & 0xff); |
|
3477 *(sp + 1) = (png_byte)(v & 0xff); |
|
3478 sp += 2; |
|
3479 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3480 *sp = (png_byte)((v >> 8) & 0xff); |
|
3481 *(sp + 1) = (png_byte)(v & 0xff); |
|
3482 sp += 4; |
|
3483 } |
|
3484 } |
|
3485 break; |
|
3486 } |
|
3487 case PNG_COLOR_TYPE_GRAY_ALPHA: |
|
3488 { |
|
3489 if (row_info->bit_depth == 8) |
|
3490 { |
|
3491 sp = row; |
|
3492 for (i = 0; i < row_width; i++) |
|
3493 { |
|
3494 *sp = gamma_table[*sp]; |
|
3495 sp += 2; |
|
3496 } |
|
3497 } |
|
3498 else /* if (row_info->bit_depth == 16) */ |
|
3499 { |
|
3500 sp = row; |
|
3501 for (i = 0; i < row_width; i++) |
|
3502 { |
|
3503 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3504 *sp = (png_byte)((v >> 8) & 0xff); |
|
3505 *(sp + 1) = (png_byte)(v & 0xff); |
|
3506 sp += 4; |
|
3507 } |
|
3508 } |
|
3509 break; |
|
3510 } |
|
3511 case PNG_COLOR_TYPE_GRAY: |
|
3512 { |
|
3513 if (row_info->bit_depth == 2) |
|
3514 { |
|
3515 sp = row; |
|
3516 for (i = 0; i < row_width; i += 4) |
|
3517 { |
|
3518 int a = *sp & 0xc0; |
|
3519 int b = *sp & 0x30; |
|
3520 int c = *sp & 0x0c; |
|
3521 int d = *sp & 0x03; |
|
3522 |
|
3523 *sp = (png_byte)( |
|
3524 ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| |
|
3525 ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| |
|
3526 ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| |
|
3527 ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) )); |
|
3528 sp++; |
|
3529 } |
|
3530 } |
|
3531 if (row_info->bit_depth == 4) |
|
3532 { |
|
3533 sp = row; |
|
3534 for (i = 0; i < row_width; i += 2) |
|
3535 { |
|
3536 int msb = *sp & 0xf0; |
|
3537 int lsb = *sp & 0x0f; |
|
3538 |
|
3539 *sp = (png_byte)((((int)gamma_table[msb | (msb >> 4)]) & 0xf0) |
|
3540 | (((int)gamma_table[(lsb << 4) | lsb]) >> 4)); |
|
3541 sp++; |
|
3542 } |
|
3543 } |
|
3544 else if (row_info->bit_depth == 8) |
|
3545 { |
|
3546 sp = row; |
|
3547 for (i = 0; i < row_width; i++) |
|
3548 { |
|
3549 *sp = gamma_table[*sp]; |
|
3550 sp++; |
|
3551 } |
|
3552 } |
|
3553 else if (row_info->bit_depth == 16) |
|
3554 { |
|
3555 sp = row; |
|
3556 for (i = 0; i < row_width; i++) |
|
3557 { |
|
3558 png_uint_16 v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; |
|
3559 *sp = (png_byte)((v >> 8) & 0xff); |
|
3560 *(sp + 1) = (png_byte)(v & 0xff); |
|
3561 sp += 2; |
|
3562 } |
|
3563 } |
|
3564 break; |
|
3565 } |
|
3566 } |
|
3567 } |
|
3568 } |
|
3569 #endif |
|
3570 |
|
3571 #if defined(PNG_READ_EXPAND_SUPPORTED) |
|
3572 /* Expands a palette row to an RGB or RGBA row depending |
|
3573 * upon whether you supply trans and num_trans. |
|
3574 */ |
|
3575 void /* PRIVATE */ |
|
3576 png_do_expand_palette(png_row_infop row_info, png_bytep row, |
|
3577 png_colorp palette, png_bytep trans, int num_trans) |
|
3578 { |
|
3579 int shift, value; |
|
3580 png_bytep sp, dp; |
|
3581 png_uint_32 i; |
|
3582 png_uint_32 row_width=row_info->width; |
|
3583 |
|
3584 png_debug(1, "in png_do_expand_palette\n"); |
|
3585 if ( |
|
3586 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
3587 row != NULL && row_info != NULL && |
|
3588 #endif |
|
3589 row_info->color_type == PNG_COLOR_TYPE_PALETTE) |
|
3590 { |
|
3591 if (row_info->bit_depth < 8) |
|
3592 { |
|
3593 switch (row_info->bit_depth) |
|
3594 { |
|
3595 case 1: |
|
3596 { |
|
3597 sp = row + (png_size_t)((row_width - 1) >> 3); |
|
3598 dp = row + (png_size_t)row_width - 1; |
|
3599 shift = 7 - (int)((row_width + 7) & 0x07); |
|
3600 for (i = 0; i < row_width; i++) |
|
3601 { |
|
3602 if ((*sp >> shift) & 0x01) |
|
3603 *dp = 1; |
|
3604 else |
|
3605 *dp = 0; |
|
3606 if (shift == 7) |
|
3607 { |
|
3608 shift = 0; |
|
3609 sp--; |
|
3610 } |
|
3611 else |
|
3612 shift++; |
|
3613 |
|
3614 dp--; |
|
3615 } |
|
3616 break; |
|
3617 } |
|
3618 case 2: |
|
3619 { |
|
3620 sp = row + (png_size_t)((row_width - 1) >> 2); |
|
3621 dp = row + (png_size_t)row_width - 1; |
|
3622 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
|
3623 for (i = 0; i < row_width; i++) |
|
3624 { |
|
3625 value = (*sp >> shift) & 0x03; |
|
3626 *dp = (png_byte)value; |
|
3627 if (shift == 6) |
|
3628 { |
|
3629 shift = 0; |
|
3630 sp--; |
|
3631 } |
|
3632 else |
|
3633 shift += 2; |
|
3634 |
|
3635 dp--; |
|
3636 } |
|
3637 break; |
|
3638 } |
|
3639 case 4: |
|
3640 { |
|
3641 sp = row + (png_size_t)((row_width - 1) >> 1); |
|
3642 dp = row + (png_size_t)row_width - 1; |
|
3643 shift = (int)((row_width & 0x01) << 2); |
|
3644 for (i = 0; i < row_width; i++) |
|
3645 { |
|
3646 value = (*sp >> shift) & 0x0f; |
|
3647 *dp = (png_byte)value; |
|
3648 if (shift == 4) |
|
3649 { |
|
3650 shift = 0; |
|
3651 sp--; |
|
3652 } |
|
3653 else |
|
3654 shift += 4; |
|
3655 |
|
3656 dp--; |
|
3657 } |
|
3658 break; |
|
3659 } |
|
3660 } |
|
3661 row_info->bit_depth = 8; |
|
3662 row_info->pixel_depth = 8; |
|
3663 row_info->rowbytes = row_width; |
|
3664 } |
|
3665 switch (row_info->bit_depth) |
|
3666 { |
|
3667 case 8: |
|
3668 { |
|
3669 if (trans != NULL) |
|
3670 { |
|
3671 sp = row + (png_size_t)row_width - 1; |
|
3672 dp = row + (png_size_t)(row_width << 2) - 1; |
|
3673 |
|
3674 for (i = 0; i < row_width; i++) |
|
3675 { |
|
3676 if ((int)(*sp) >= num_trans) |
|
3677 *dp-- = 0xff; |
|
3678 else |
|
3679 *dp-- = trans[*sp]; |
|
3680 *dp-- = palette[*sp].blue; |
|
3681 *dp-- = palette[*sp].green; |
|
3682 *dp-- = palette[*sp].red; |
|
3683 sp--; |
|
3684 } |
|
3685 row_info->bit_depth = 8; |
|
3686 row_info->pixel_depth = 32; |
|
3687 row_info->rowbytes = row_width * 4; |
|
3688 row_info->color_type = 6; |
|
3689 row_info->channels = 4; |
|
3690 } |
|
3691 else |
|
3692 { |
|
3693 sp = row + (png_size_t)row_width - 1; |
|
3694 dp = row + (png_size_t)(row_width * 3) - 1; |
|
3695 |
|
3696 for (i = 0; i < row_width; i++) |
|
3697 { |
|
3698 *dp-- = palette[*sp].blue; |
|
3699 *dp-- = palette[*sp].green; |
|
3700 *dp-- = palette[*sp].red; |
|
3701 sp--; |
|
3702 } |
|
3703 row_info->bit_depth = 8; |
|
3704 row_info->pixel_depth = 24; |
|
3705 row_info->rowbytes = row_width * 3; |
|
3706 row_info->color_type = 2; |
|
3707 row_info->channels = 3; |
|
3708 } |
|
3709 break; |
|
3710 } |
|
3711 } |
|
3712 } |
|
3713 } |
|
3714 |
|
3715 /* If the bit depth < 8, it is expanded to 8. Also, if the already |
|
3716 * expanded transparency value is supplied, an alpha channel is built. |
|
3717 */ |
|
3718 void /* PRIVATE */ |
|
3719 png_do_expand(png_row_infop row_info, png_bytep row, |
|
3720 png_color_16p trans_value) |
|
3721 { |
|
3722 int shift, value; |
|
3723 png_bytep sp, dp; |
|
3724 png_uint_32 i; |
|
3725 png_uint_32 row_width=row_info->width; |
|
3726 |
|
3727 png_debug(1, "in png_do_expand\n"); |
|
3728 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
3729 if (row != NULL && row_info != NULL) |
|
3730 #endif |
|
3731 { |
|
3732 if (row_info->color_type == PNG_COLOR_TYPE_GRAY) |
|
3733 { |
|
3734 png_uint_16 gray = (png_uint_16)(trans_value ? trans_value->gray : 0); |
|
3735 |
|
3736 if (row_info->bit_depth < 8) |
|
3737 { |
|
3738 switch (row_info->bit_depth) |
|
3739 { |
|
3740 case 1: |
|
3741 { |
|
3742 gray = (png_uint_16)((gray&0x01)*0xff); |
|
3743 sp = row + (png_size_t)((row_width - 1) >> 3); |
|
3744 dp = row + (png_size_t)row_width - 1; |
|
3745 shift = 7 - (int)((row_width + 7) & 0x07); |
|
3746 for (i = 0; i < row_width; i++) |
|
3747 { |
|
3748 if ((*sp >> shift) & 0x01) |
|
3749 *dp = 0xff; |
|
3750 else |
|
3751 *dp = 0; |
|
3752 if (shift == 7) |
|
3753 { |
|
3754 shift = 0; |
|
3755 sp--; |
|
3756 } |
|
3757 else |
|
3758 shift++; |
|
3759 |
|
3760 dp--; |
|
3761 } |
|
3762 break; |
|
3763 } |
|
3764 case 2: |
|
3765 { |
|
3766 gray = (png_uint_16)((gray&0x03)*0x55); |
|
3767 sp = row + (png_size_t)((row_width - 1) >> 2); |
|
3768 dp = row + (png_size_t)row_width - 1; |
|
3769 shift = (int)((3 - ((row_width + 3) & 0x03)) << 1); |
|
3770 for (i = 0; i < row_width; i++) |
|
3771 { |
|
3772 value = (*sp >> shift) & 0x03; |
|
3773 *dp = (png_byte)(value | (value << 2) | (value << 4) | |
|
3774 (value << 6)); |
|
3775 if (shift == 6) |
|
3776 { |
|
3777 shift = 0; |
|
3778 sp--; |
|
3779 } |
|
3780 else |
|
3781 shift += 2; |
|
3782 |
|
3783 dp--; |
|
3784 } |
|
3785 break; |
|
3786 } |
|
3787 case 4: |
|
3788 { |
|
3789 gray = (png_uint_16)((gray&0x0f)*0x11); |
|
3790 sp = row + (png_size_t)((row_width - 1) >> 1); |
|
3791 dp = row + (png_size_t)row_width - 1; |
|
3792 shift = (int)((1 - ((row_width + 1) & 0x01)) << 2); |
|
3793 for (i = 0; i < row_width; i++) |
|
3794 { |
|
3795 value = (*sp >> shift) & 0x0f; |
|
3796 *dp = (png_byte)(value | (value << 4)); |
|
3797 if (shift == 4) |
|
3798 { |
|
3799 shift = 0; |
|
3800 sp--; |
|
3801 } |
|
3802 else |
|
3803 shift = 4; |
|
3804 |
|
3805 dp--; |
|
3806 } |
|
3807 break; |
|
3808 } |
|
3809 } |
|
3810 row_info->bit_depth = 8; |
|
3811 row_info->pixel_depth = 8; |
|
3812 row_info->rowbytes = row_width; |
|
3813 } |
|
3814 |
|
3815 if (trans_value != NULL) |
|
3816 { |
|
3817 if (row_info->bit_depth == 8) |
|
3818 { |
|
3819 gray = gray & 0xff; |
|
3820 sp = row + (png_size_t)row_width - 1; |
|
3821 dp = row + (png_size_t)(row_width << 1) - 1; |
|
3822 for (i = 0; i < row_width; i++) |
|
3823 { |
|
3824 if (*sp == gray) |
|
3825 *dp-- = 0; |
|
3826 else |
|
3827 *dp-- = 0xff; |
|
3828 *dp-- = *sp--; |
|
3829 } |
|
3830 } |
|
3831 else if (row_info->bit_depth == 16) |
|
3832 { |
|
3833 png_byte gray_high = (gray >> 8) & 0xff; |
|
3834 png_byte gray_low = gray & 0xff; |
|
3835 sp = row + row_info->rowbytes - 1; |
|
3836 dp = row + (row_info->rowbytes << 1) - 1; |
|
3837 for (i = 0; i < row_width; i++) |
|
3838 { |
|
3839 if (*(sp - 1) == gray_high && *(sp) == gray_low) |
|
3840 { |
|
3841 *dp-- = 0; |
|
3842 *dp-- = 0; |
|
3843 } |
|
3844 else |
|
3845 { |
|
3846 *dp-- = 0xff; |
|
3847 *dp-- = 0xff; |
|
3848 } |
|
3849 *dp-- = *sp--; |
|
3850 *dp-- = *sp--; |
|
3851 } |
|
3852 } |
|
3853 row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; |
|
3854 row_info->channels = 2; |
|
3855 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); |
|
3856 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, |
|
3857 row_width); |
|
3858 } |
|
3859 } |
|
3860 else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value) |
|
3861 { |
|
3862 if (row_info->bit_depth == 8) |
|
3863 { |
|
3864 png_byte red = trans_value->red & 0xff; |
|
3865 png_byte green = trans_value->green & 0xff; |
|
3866 png_byte blue = trans_value->blue & 0xff; |
|
3867 sp = row + (png_size_t)row_info->rowbytes - 1; |
|
3868 dp = row + (png_size_t)(row_width << 2) - 1; |
|
3869 for (i = 0; i < row_width; i++) |
|
3870 { |
|
3871 if (*(sp - 2) == red && *(sp - 1) == green && *(sp) == blue) |
|
3872 *dp-- = 0; |
|
3873 else |
|
3874 *dp-- = 0xff; |
|
3875 *dp-- = *sp--; |
|
3876 *dp-- = *sp--; |
|
3877 *dp-- = *sp--; |
|
3878 } |
|
3879 } |
|
3880 else if (row_info->bit_depth == 16) |
|
3881 { |
|
3882 png_byte red_high = (trans_value->red >> 8) & 0xff; |
|
3883 png_byte green_high = (trans_value->green >> 8) & 0xff; |
|
3884 png_byte blue_high = (trans_value->blue >> 8) & 0xff; |
|
3885 png_byte red_low = trans_value->red & 0xff; |
|
3886 png_byte green_low = trans_value->green & 0xff; |
|
3887 png_byte blue_low = trans_value->blue & 0xff; |
|
3888 sp = row + row_info->rowbytes - 1; |
|
3889 dp = row + (png_size_t)(row_width << 3) - 1; |
|
3890 for (i = 0; i < row_width; i++) |
|
3891 { |
|
3892 if (*(sp - 5) == red_high && |
|
3893 *(sp - 4) == red_low && |
|
3894 *(sp - 3) == green_high && |
|
3895 *(sp - 2) == green_low && |
|
3896 *(sp - 1) == blue_high && |
|
3897 *(sp ) == blue_low) |
|
3898 { |
|
3899 *dp-- = 0; |
|
3900 *dp-- = 0; |
|
3901 } |
|
3902 else |
|
3903 { |
|
3904 *dp-- = 0xff; |
|
3905 *dp-- = 0xff; |
|
3906 } |
|
3907 *dp-- = *sp--; |
|
3908 *dp-- = *sp--; |
|
3909 *dp-- = *sp--; |
|
3910 *dp-- = *sp--; |
|
3911 *dp-- = *sp--; |
|
3912 *dp-- = *sp--; |
|
3913 } |
|
3914 } |
|
3915 row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; |
|
3916 row_info->channels = 4; |
|
3917 row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); |
|
3918 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
3919 } |
|
3920 } |
|
3921 } |
|
3922 #endif |
|
3923 |
|
3924 #if defined(PNG_READ_DITHER_SUPPORTED) |
|
3925 void /* PRIVATE */ |
|
3926 png_do_dither(png_row_infop row_info, png_bytep row, |
|
3927 png_bytep palette_lookup, png_bytep dither_lookup) |
|
3928 { |
|
3929 png_bytep sp, dp; |
|
3930 png_uint_32 i; |
|
3931 png_uint_32 row_width=row_info->width; |
|
3932 |
|
3933 png_debug(1, "in png_do_dither\n"); |
|
3934 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
3935 if (row != NULL && row_info != NULL) |
|
3936 #endif |
|
3937 { |
|
3938 if (row_info->color_type == PNG_COLOR_TYPE_RGB && |
|
3939 palette_lookup && row_info->bit_depth == 8) |
|
3940 { |
|
3941 int r, g, b, p; |
|
3942 sp = row; |
|
3943 dp = row; |
|
3944 for (i = 0; i < row_width; i++) |
|
3945 { |
|
3946 r = *sp++; |
|
3947 g = *sp++; |
|
3948 b = *sp++; |
|
3949 |
|
3950 /* this looks real messy, but the compiler will reduce |
|
3951 it down to a reasonable formula. For example, with |
|
3952 5 bits per color, we get: |
|
3953 p = (((r >> 3) & 0x1f) << 10) | |
|
3954 (((g >> 3) & 0x1f) << 5) | |
|
3955 ((b >> 3) & 0x1f); |
|
3956 */ |
|
3957 p = (((r >> (8 - PNG_DITHER_RED_BITS)) & |
|
3958 ((1 << PNG_DITHER_RED_BITS) - 1)) << |
|
3959 (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | |
|
3960 (((g >> (8 - PNG_DITHER_GREEN_BITS)) & |
|
3961 ((1 << PNG_DITHER_GREEN_BITS) - 1)) << |
|
3962 (PNG_DITHER_BLUE_BITS)) | |
|
3963 ((b >> (8 - PNG_DITHER_BLUE_BITS)) & |
|
3964 ((1 << PNG_DITHER_BLUE_BITS) - 1)); |
|
3965 |
|
3966 *dp++ = palette_lookup[p]; |
|
3967 } |
|
3968 row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
|
3969 row_info->channels = 1; |
|
3970 row_info->pixel_depth = row_info->bit_depth; |
|
3971 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
3972 } |
|
3973 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && |
|
3974 palette_lookup != NULL && row_info->bit_depth == 8) |
|
3975 { |
|
3976 int r, g, b, p; |
|
3977 sp = row; |
|
3978 dp = row; |
|
3979 for (i = 0; i < row_width; i++) |
|
3980 { |
|
3981 r = *sp++; |
|
3982 g = *sp++; |
|
3983 b = *sp++; |
|
3984 sp++; |
|
3985 |
|
3986 p = (((r >> (8 - PNG_DITHER_RED_BITS)) & |
|
3987 ((1 << PNG_DITHER_RED_BITS) - 1)) << |
|
3988 (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | |
|
3989 (((g >> (8 - PNG_DITHER_GREEN_BITS)) & |
|
3990 ((1 << PNG_DITHER_GREEN_BITS) - 1)) << |
|
3991 (PNG_DITHER_BLUE_BITS)) | |
|
3992 ((b >> (8 - PNG_DITHER_BLUE_BITS)) & |
|
3993 ((1 << PNG_DITHER_BLUE_BITS) - 1)); |
|
3994 |
|
3995 *dp++ = palette_lookup[p]; |
|
3996 } |
|
3997 row_info->color_type = PNG_COLOR_TYPE_PALETTE; |
|
3998 row_info->channels = 1; |
|
3999 row_info->pixel_depth = row_info->bit_depth; |
|
4000 row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, row_width); |
|
4001 } |
|
4002 else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && |
|
4003 dither_lookup && row_info->bit_depth == 8) |
|
4004 { |
|
4005 sp = row; |
|
4006 for (i = 0; i < row_width; i++, sp++) |
|
4007 { |
|
4008 *sp = dither_lookup[*sp]; |
|
4009 } |
|
4010 } |
|
4011 } |
|
4012 } |
|
4013 #endif |
|
4014 |
|
4015 #ifdef PNG_FLOATING_POINT_SUPPORTED |
|
4016 #if defined(PNG_READ_GAMMA_SUPPORTED) |
|
4017 static PNG_CONST int png_gamma_shift[] = |
|
4018 {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0, 0x00}; |
|
4019 |
|
4020 /* We build the 8- or 16-bit gamma tables here. Note that for 16-bit |
|
4021 * tables, we don't make a full table if we are reducing to 8-bit in |
|
4022 * the future. Note also how the gamma_16 tables are segmented so that |
|
4023 * we don't need to allocate > 64K chunks for a full 16-bit table. |
|
4024 */ |
|
4025 void /* PRIVATE */ |
|
4026 png_build_gamma_table(png_structp png_ptr) |
|
4027 { |
|
4028 png_debug(1, "in png_build_gamma_table\n"); |
|
4029 |
|
4030 if (png_ptr->bit_depth <= 8) |
|
4031 { |
|
4032 int i; |
|
4033 double g; |
|
4034 |
|
4035 if (png_ptr->screen_gamma > .000001) |
|
4036 g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
|
4037 else |
|
4038 g = 1.0; |
|
4039 |
|
4040 png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr, |
|
4041 (png_uint_32)256); |
|
4042 |
|
4043 for (i = 0; i < 256; i++) |
|
4044 { |
|
4045 png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0, |
|
4046 g) * 255.0 + .5); |
|
4047 } |
|
4048 |
|
4049 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ |
|
4050 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
4051 if (png_ptr->transformations & ((PNG_BACKGROUND) | PNG_RGB_TO_GRAY)) |
|
4052 { |
|
4053 |
|
4054 g = 1.0 / (png_ptr->gamma); |
|
4055 |
|
4056 png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr, |
|
4057 (png_uint_32)256); |
|
4058 |
|
4059 for (i = 0; i < 256; i++) |
|
4060 { |
|
4061 png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0, |
|
4062 g) * 255.0 + .5); |
|
4063 } |
|
4064 |
|
4065 |
|
4066 png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr, |
|
4067 (png_uint_32)256); |
|
4068 |
|
4069 if (png_ptr->screen_gamma > 0.000001) |
|
4070 g = 1.0 / png_ptr->screen_gamma; |
|
4071 else |
|
4072 g = png_ptr->gamma; /* probably doing rgb_to_gray */ |
|
4073 |
|
4074 for (i = 0; i < 256; i++) |
|
4075 { |
|
4076 png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0, |
|
4077 g) * 255.0 + .5); |
|
4078 |
|
4079 } |
|
4080 } |
|
4081 #endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ |
|
4082 } |
|
4083 else |
|
4084 { |
|
4085 double g; |
|
4086 int i, j, shift, num; |
|
4087 int sig_bit; |
|
4088 png_uint_32 ig; |
|
4089 |
|
4090 if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) |
|
4091 { |
|
4092 sig_bit = (int)png_ptr->sig_bit.red; |
|
4093 if ((int)png_ptr->sig_bit.green > sig_bit) |
|
4094 sig_bit = png_ptr->sig_bit.green; |
|
4095 if ((int)png_ptr->sig_bit.blue > sig_bit) |
|
4096 sig_bit = png_ptr->sig_bit.blue; |
|
4097 } |
|
4098 else |
|
4099 { |
|
4100 sig_bit = (int)png_ptr->sig_bit.gray; |
|
4101 } |
|
4102 |
|
4103 if (sig_bit > 0) |
|
4104 shift = 16 - sig_bit; |
|
4105 else |
|
4106 shift = 0; |
|
4107 |
|
4108 if (png_ptr->transformations & PNG_16_TO_8) |
|
4109 { |
|
4110 if (shift < (16 - PNG_MAX_GAMMA_8)) |
|
4111 shift = (16 - PNG_MAX_GAMMA_8); |
|
4112 } |
|
4113 |
|
4114 if (shift > 8) |
|
4115 shift = 8; |
|
4116 if (shift < 0) |
|
4117 shift = 0; |
|
4118 |
|
4119 png_ptr->gamma_shift = (png_byte)shift; |
|
4120 |
|
4121 num = (1 << (8 - shift)); |
|
4122 |
|
4123 if (png_ptr->screen_gamma > .000001) |
|
4124 g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); |
|
4125 else |
|
4126 g = 1.0; |
|
4127 |
|
4128 png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr, |
|
4129 (png_uint_32)(num * png_sizeof(png_uint_16p))); |
|
4130 |
|
4131 if (png_ptr->transformations & (PNG_16_TO_8 | PNG_BACKGROUND)) |
|
4132 { |
|
4133 double fin, fout; |
|
4134 png_uint_32 last, max; |
|
4135 |
|
4136 for (i = 0; i < num; i++) |
|
4137 { |
|
4138 png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, |
|
4139 (png_uint_32)(256 * png_sizeof(png_uint_16))); |
|
4140 } |
|
4141 |
|
4142 g = 1.0 / g; |
|
4143 last = 0; |
|
4144 for (i = 0; i < 256; i++) |
|
4145 { |
|
4146 fout = ((double)i + 0.5) / 256.0; |
|
4147 fin = pow(fout, g); |
|
4148 max = (png_uint_32)(fin * (double)((png_uint_32)num << 8)); |
|
4149 while (last <= max) |
|
4150 { |
|
4151 png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] |
|
4152 [(int)(last >> (8 - shift))] = (png_uint_16)( |
|
4153 (png_uint_16)i | ((png_uint_16)i << 8)); |
|
4154 last++; |
|
4155 } |
|
4156 } |
|
4157 while (last < ((png_uint_32)num << 8)) |
|
4158 { |
|
4159 png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] |
|
4160 [(int)(last >> (8 - shift))] = (png_uint_16)65535L; |
|
4161 last++; |
|
4162 } |
|
4163 } |
|
4164 else |
|
4165 { |
|
4166 for (i = 0; i < num; i++) |
|
4167 { |
|
4168 png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, |
|
4169 (png_uint_32)(256 * png_sizeof(png_uint_16))); |
|
4170 |
|
4171 ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4); |
|
4172 for (j = 0; j < 256; j++) |
|
4173 { |
|
4174 png_ptr->gamma_16_table[i][j] = |
|
4175 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
|
4176 65535.0, g) * 65535.0 + .5); |
|
4177 } |
|
4178 } |
|
4179 } |
|
4180 |
|
4181 #if defined(PNG_READ_BACKGROUND_SUPPORTED) || \ |
|
4182 defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) |
|
4183 if (png_ptr->transformations & (PNG_BACKGROUND | PNG_RGB_TO_GRAY)) |
|
4184 { |
|
4185 |
|
4186 g = 1.0 / (png_ptr->gamma); |
|
4187 |
|
4188 png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr, |
|
4189 (png_uint_32)(num * png_sizeof(png_uint_16p ))); |
|
4190 |
|
4191 for (i = 0; i < num; i++) |
|
4192 { |
|
4193 png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr, |
|
4194 (png_uint_32)(256 * png_sizeof(png_uint_16))); |
|
4195 |
|
4196 ig = (((png_uint_32)i * |
|
4197 (png_uint_32)png_gamma_shift[shift]) >> 4); |
|
4198 for (j = 0; j < 256; j++) |
|
4199 { |
|
4200 png_ptr->gamma_16_to_1[i][j] = |
|
4201 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
|
4202 65535.0, g) * 65535.0 + .5); |
|
4203 } |
|
4204 } |
|
4205 |
|
4206 if (png_ptr->screen_gamma > 0.000001) |
|
4207 g = 1.0 / png_ptr->screen_gamma; |
|
4208 else |
|
4209 g = png_ptr->gamma; /* probably doing rgb_to_gray */ |
|
4210 |
|
4211 png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr, |
|
4212 (png_uint_32)(num * png_sizeof(png_uint_16p))); |
|
4213 |
|
4214 for (i = 0; i < num; i++) |
|
4215 { |
|
4216 png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr, |
|
4217 (png_uint_32)(256 * png_sizeof(png_uint_16))); |
|
4218 |
|
4219 ig = (((png_uint_32)i * |
|
4220 (png_uint_32)png_gamma_shift[shift]) >> 4); |
|
4221 for (j = 0; j < 256; j++) |
|
4222 { |
|
4223 png_ptr->gamma_16_from_1[i][j] = |
|
4224 (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / |
|
4225 65535.0, g) * 65535.0 + .5); |
|
4226 } |
|
4227 } |
|
4228 } |
|
4229 #endif /* PNG_READ_BACKGROUND_SUPPORTED || PNG_RGB_TO_GRAY_SUPPORTED */ |
|
4230 } |
|
4231 } |
|
4232 #endif |
|
4233 /* To do: install integer version of png_build_gamma_table here */ |
|
4234 #endif |
|
4235 |
|
4236 #if defined(PNG_MNG_FEATURES_SUPPORTED) |
|
4237 /* undoes intrapixel differencing */ |
|
4238 void /* PRIVATE */ |
|
4239 png_do_read_intrapixel(png_row_infop row_info, png_bytep row) |
|
4240 { |
|
4241 png_debug(1, "in png_do_read_intrapixel\n"); |
|
4242 if ( |
|
4243 #if defined(PNG_USELESS_TESTS_SUPPORTED) |
|
4244 row != NULL && row_info != NULL && |
|
4245 #endif |
|
4246 (row_info->color_type & PNG_COLOR_MASK_COLOR)) |
|
4247 { |
|
4248 int bytes_per_pixel; |
|
4249 png_uint_32 row_width = row_info->width; |
|
4250 if (row_info->bit_depth == 8) |
|
4251 { |
|
4252 png_bytep rp; |
|
4253 png_uint_32 i; |
|
4254 |
|
4255 if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
4256 bytes_per_pixel = 3; |
|
4257 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
4258 bytes_per_pixel = 4; |
|
4259 else |
|
4260 return; |
|
4261 |
|
4262 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) |
|
4263 { |
|
4264 *(rp) = (png_byte)((256 + *rp + *(rp+1))&0xff); |
|
4265 *(rp+2) = (png_byte)((256 + *(rp+2) + *(rp+1))&0xff); |
|
4266 } |
|
4267 } |
|
4268 else if (row_info->bit_depth == 16) |
|
4269 { |
|
4270 png_bytep rp; |
|
4271 png_uint_32 i; |
|
4272 |
|
4273 if (row_info->color_type == PNG_COLOR_TYPE_RGB) |
|
4274 bytes_per_pixel = 6; |
|
4275 else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) |
|
4276 bytes_per_pixel = 8; |
|
4277 else |
|
4278 return; |
|
4279 |
|
4280 for (i = 0, rp = row; i < row_width; i++, rp += bytes_per_pixel) |
|
4281 { |
|
4282 png_uint_32 s0 = (*(rp ) << 8) | *(rp + 1); |
|
4283 png_uint_32 s1 = (*(rp + 2) << 8) | *(rp + 3); |
|
4284 png_uint_32 s2 = (*(rp + 4) << 8) | *(rp + 5); |
|
4285 png_uint_32 red = (png_uint_32)((s0 + s1 + 65536L) & 0xffffL); |
|
4286 png_uint_32 blue = (png_uint_32)((s2 + s1 + 65536L) & 0xffffL); |
|
4287 *(rp ) = (png_byte)((red >> 8) & 0xff); |
|
4288 *(rp+1) = (png_byte)(red & 0xff); |
|
4289 *(rp+4) = (png_byte)((blue >> 8) & 0xff); |
|
4290 *(rp+5) = (png_byte)(blue & 0xff); |
|
4291 } |
|
4292 } |
|
4293 } |
|
4294 } |
|
4295 #endif /* PNG_MNG_FEATURES_SUPPORTED */ |
|
4296 #endif /* PNG_READ_SUPPORTED */ |