Stretch parameters: the input range that is stretched to full black..white.
Points are sRGB-encoded values (0-1 for the image as decoded; values above 1
reach highlights pushed past white by earlier steps). Give one number for
all channels or [R, G, B].
Stretch parameters: the input range that is stretched to full black..white. Points are sRGB-encoded values (0-1 for the image as decoded; values above 1 reach highlights pushed past white by earlier steps). Give one number for all channels or
[R, G, B].