odin-color

Searchable documentation is available at https://calebmanning.net/odin-color/.

A simple library for color conversions between xyz color rgb color and sigmoided polynomial spectral representations as outlined in https://www.pbrt.org/. However I use the actual jacobian for gauss newton optimization since it gives a smaller error to the target color.

This library also provides conversions based on approximate color match functions and whitepoint functions which can be cheaper when you need to perform conversions back on the gpu.

This library is used by bonsai_rt my physically based renderer.

Example converting to sigmoided polynomial representations and back again

xyz := srgb_to_xyz(srgbu8_to_srgb(SRGBU8Color{34, 167, 89}))
spoly, err := xyz_d65_to_spoly(xyz)

xyz_or_spoly := spoly_to_xyz_d65(spoly)
assert(linalg.length(xyz_or_spoly - xyz) < 1e-3)

Example using approximations of the xyz color match functions and d65 white point

xyz := srgb_to_xyz(srgbu8_to_srgb(rgb))
spoly, err := approximate_xyz_d65_to_spoly(xyz)

xyz_or_spoly := approximate_spoly_to_xyz_d65(spoly)
assert(linalg.length(xyz_or_spoly - xyz) < 1e-3)