Support sRGB chunk to get rendering intent
The PNG loader doesn't decode the sRGB
chunk; it contains the rendering intent. I think we can just use png_get_sRGB()
; see !11 for how this interacts with the presence of gAMA
and cHRM
.
Related: #104 about documenting color space information.
/* These are for the sRGB chunk. These values should NOT be changed. */
#define PNG_sRGB_INTENT_PERCEPTUAL 0
#define PNG_sRGB_INTENT_RELATIVE 1
#define PNG_sRGB_INTENT_SATURATION 2
#define PNG_sRGB_INTENT_ABSOLUTE 3