--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/holdingarea/vg/bin/make_gamma_lut.py Thu Sep 16 09:43:14 2010 +0100
@@ -0,0 +1,81 @@
+#! /usr/bin/python
+# Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and /or associated documentation files
+# (the "Materials "), to deal in the Materials without restriction,
+# including without limitation the rights to use, copy, modify, merge,
+# publish, distribute, sublicense, and/or sell copies of the Materials,
+# and to permit persons to whom the Materials are furnished to do so,
+# subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Materials.
+#
+# THE MATERIALS ARE PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+# DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+# OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE MATERIALS OR
+# THE USE OR OTHER DEALINGS IN THE MATERIALS.
+
+# Extremely coarse lrgb<->srgb conversion table generation
+
+from c_utils import *
+
+GAMMA_BITS = 8
+
+def linear_to_gamma(f):
+ if f <= 0.00304:
+ return 12.92 * f
+ return 1.0556*pow(f, 1/2.4) - 0.0556
+
+def gamma_to_linear(f):
+ if f <= 0.03928:
+ return f / 12.92
+ return pow((f+0.0556)/1.0556, 2.4)
+
+def clamp(i, mn, mx):
+ if i < mn:
+ return mn
+ if i > mx:
+ return mx
+ return i
+
+def icolortof(i):
+ return i / 255.0
+
+def fcolortoi(f):
+ return int(f * ((1<<GAMMA_BITS)-1) + 0.5)
+
+all_components = range(0,256)
+all_floats = map(icolortof, all_components)
+
+def make_color_list(conv_func):
+ return map(fcolortoi, map(conv_func, all_floats))
+
+def make_lut_array(name, data):
+ make_array("static const", "RIuint8", name, data, hex_formatter)
+
+def print_lrgb_to_srgb_table():
+ make_lut_array("sc_lRGB_to_sRGB", make_color_list(linear_to_gamma))
+
+def print_srgb_to_lrgb_table():
+ make_lut_array("sc_sRGB_to_lRGB", make_color_list(gamma_to_linear))
+
+def print_lookups():
+ begin_include_guard("_SFGAMMARCP_H_")
+ print ""
+ make_include("riDefs.h")
+ print ""
+ begin_namespace("OpenVGRI")
+ print_srgb_to_lrgb_table()
+ print ""
+ print_lrgb_to_srgb_table()
+ end_namespace()
+ end_include_guard()
+
+if __name__ == '__main__':
+ print_lookups()
+