png_set_rgb_to_gray_fixed 1162 3rdparty/libpng/png.h PNG_FIXED_EXPORT(33, void, png_set_rgb_to_gray_fixed, (png_structp png_ptr, png_set_rgb_to_gray_fixed 1019 3rdparty/libpng/pngrtran.c png_set_rgb_to_gray_fixed(png_ptr, error_action,