Please see the Usage documentation for basic usage.
This is a living document / work in progress!
Basic identify usage:
colorist identify image.png
Dumping the pixel values of a 2x2 rect at (100,1000):
colorist identify image.png -z 100,1000,2,2
Basic conversion, leaving the source's ICC profile completely intact:
colorist convert src.png dst.png
Autograding an image's max luminance and gamma curve:
colorist convert -a src.png dst.png
Converting an image to DCI P3 at 300 nits:
colorist convert -p p3 -g 2.4 -l 300 src.png dst.png
Converting an image to BT. 2020 (HDR10's color primaries), with 10,000 nits luminance and a basic gamma curve:
colorist convert -p bt2020 -g 2.4 -l 10000 src.png dst.png
Compressing to JPEG2000 with a rate of 100x:
colorist convert -r 100 src.png dst.jp2
Extract an ICC profile from an image:
colorist convert src.png dst.icc
Convert an image to a made-up ICC profile (also generated below):
colorist convert src.png dst.png -p bt709 -l 300 -g 2.4 -d "My sRGB Profile" -c "(c) Me 2018"
Generate an sRGB ICC profile with a max luminance of 300 nits and a custom description & copyright:
colorist generate mysrgb.icc -p bt709 -l 300 -g 2.4 -d "My sRGB Profile" -c "(c) Me 2018"
Generate a 4K black to red 8-bit gradient (left to right):
colorist generate -b 8 "3840x2160,(0,0,0)..(255,0,0)" gradient.png
Generate a 4K black to red 8-bit gradient (top to bottom):
colorist generate -b 8 "2160x3840,(0,0,0)..(255,0,0),cw" gradient.png
Generate a 4K black to red 16-bit gradient (top to bottom):
colorist generate "2160x3840,(0,0,0)..(255,0,0),cw" gradient.png
Generate the SMPTE color bars:
colorist generate "640x320, #c0c0c0, #c0c000, #00c0c0, #00c000, #c000c0, #c00000, #0000c0 / 640x40, #0000c0, #000000, #c000c0, #000000, #00c0c0, #000000, #c0c0c0 / 640x120, #00214C, x3, #ffffff, x3, #32006A, x3, #131313, x3, #000000, #090909, #1D1D1D, #131313, x3" smpte.png
Generate the Macbeth chart:
colorist generate "1920x270,xyY(0.400, 0.350, 0.101), xyY(0.377, 0.345, 0.358), xyY(0.247, 0.251, 0.193), xyY(0.337, 0.422, 0.133), xyY(0.265, 0.240, 0.243), xyY(0.261, 0.343, 0.431) / xyY(0.506, 0.407, 0.301), xyY(0.211, 0.175, 0.120), xyY(0.453, 0.306, 0.198), xyY(0.285, 0.202, 0.066), xyY(0.380, 0.489, 0.443), xyY(0.473, 0.438, 0.431) / xyY(0.187, 0.129, 0.061), xyY(0.305, 0.478, 0.234), xyY(0.539, 0.313, 0.120), xyY(0.448, 0.470, 0.591), xyY(0.364, 0.233, 0.198), xyY(0.196, 0.252, 0.198) / xyY(0.310, 0.316, 0.900), xyY(0.310, 0.316, 0.591), xyY(0.310, 0.316, 0.362), xyY(0.310, 0.316, 0.198), xyY(0.310, 0.316, 0.090), xyY(0.310, 0.316, 0.031)" macbeth.png
Many more image string examples are in the Usage section.