test/lcms/gamma.c

   1 #include <lcms2.h>
   2
   3 #include <stdio.h>
   4
   5 // get gamma from ICC file
   6
   7 int main(int argc, char **argv)
   8 {
   9     char *filename;
  10     cmsHPROFILE hProfile;
  11     cmsToneCurve *tc_red, *tc_green, *tc_blue;
  12     int i;
  13
  14     if (argc == 2)
  15     {
  16         filename = argv[1];
  17     }
  18     else
  19     {
  20         filename = "SYS:Prefs/Presets/Colortables/ICC/sRGB.icc";
  21     }
  22
  23     hProfile = cmsOpenProfileFromFile(filename, "r");
  24     if (hProfile)
  25     {
  26         tc_red = cmsReadTag(hProfile, cmsSigRedTRCTag);
  27         tc_green = cmsReadTag(hProfile, cmsSigGreenTRCTag);
  28         tc_blue = cmsReadTag(hProfile, cmsSigBlueTRCTag);
  29         if (tc_red && tc_green && tc_blue)
  30         {
  31             for (i=0; i < 256; i++)
  32             {
  33                 printf("i %d red %u green %u blue %u\n", i, cmsEvalToneCurve16(tc_red, i * 256) >> 8, cmsEvalToneCurve16(tc_green, i * 256) >> 8, cmsEvalToneCurve16(tc_blue, i * 256) >> 8);
  34             }
  35         }
  36         else
  37         {
  38             puts("Gamma tags missing");
  39         }
  40         cmsCloseProfile(hProfile);
  41     }
  42     else
  43     {
  44         puts("Couldn't open ICC file");
  45         return 1;
  46     }
  47     return 0;
  48 }