PNG_GAMMA_sRGB_INVERSE  201 3rdparty/libpng/pngrtran.c          output_gamma = PNG_GAMMA_sRGB_INVERSE;
PNG_GAMMA_sRGB_INVERSE  599 3rdparty/libpng/pngset.c    png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_sRGB_INVERSE);