Crate colcon

Simple colorspace conversions in pure Rust.

All conversions are in-place, except when converting to/from integer and hexadecimal. Formulas are generally taken from Wikipedia with correctness verified against both https://www.easyrgb.com and BABL.

Helmholtz-Kohlrausch compensation formulae sourced from https://onlinelibrary.wiley.com/doi/10.1002/col.22839

This crate references CIE Standard Illuminant D65 for functions to/from CIE XYZ

Enums

• Space
  Defines colorspace pixels will take.

Constants

• D65
  Standard Illuminant D65.
• HIGH2023_MEAN
  Mean value of the HK delta, High et al 2023 implementation. Measured with 36000 steps in the hk_exmample file @ 100 C(ab) Cannot make a const fn: https://github.com/rust-lang/rust/issues/57241

Functions

• convert_space
  Runs conversion functions to convert pixel from one Space to another in the least possible moves.
• convert_space_alpha
  Same as convert_space, ignores the 4th value in pixel. Just a convenience function.
• convert_space_chunked
  Runs conversion functions to convert pixel from one Space to another in the least possible moves. Caches conversion graph for faster iteration.
• convert_space_ffi
  Same as convert_space_sliced but with FFI types. Returns 0 on success, 1 on invalid from, 2 on invalid to, 3 on invalid pixels
• convert_space_sliced
  Runs conversion functions to convert pixel from one Space to another in the least possible moves. Caches conversion graph for faster iteration. Ignores remainder values in slice.
• correct_gamma
  Gamma corrects a single linear light value
• expand_gamma
  Expand gamma of a single value to linear light
• hex_to_irgb
  Create integer RGB set from hex string. Not RGB specific, but other formats typically aren’t represented as hexadecimal.
• hk_comp_2023
  Compensates LCH’s L value for the Helmholtz-Kohlrausch effect. High et al 2023 implementation.
• hk_delta_2023
  Returns difference in perceptual lightness based on hue, aka the Helmholtz-Kohlrausch effect. High et al 2023 implementation.
• hsv_to_srgb
  Convert from HSV to sRGB.
• irgb_to_hex
  Create a hexadecimal string from integer RGB. Not RGB specific, but other formats typically aren’t represented as hexadecimal.
• irgb_to_srgb
  Convert integer (0..255) RGB to floating (0.0..1.0) RGB. Not RGB specific, but other formats typically aren’t represented as integers.
• lab_to_lch
  Convert from CIE LAB to CIE LCH. https://en.wikipedia.org/wiki/CIELAB_color_space#Cylindrical_model
• lab_to_xyz
  Convert from CIE LAB to CIE XYZ. https://en.wikipedia.org/wiki/CIELAB_color_space#From_CIELAB_to_CIEXYZ
• lch_to_lab
  Convert from CIE LCH to CIE LAB. https://en.wikipedia.org/wiki/CIELAB_color_space#Cylindrical_model
• lrgb_to_srgb
  Convert from Linear Light RGB to sRGB. https://en.wikipedia.org/wiki/SRGB#From_CIE_XYZ_to_sRGB
• lrgb_to_xyz
  Convert from Linear Light RGB to CIE XYZ, D65 standard illuminant https://en.wikipedia.org/wiki/SRGB#From_sRGB_to_CIE_XYZ
• oklab_to_xyz
  Convert from OKLAB to CIE XYZ. https://bottosson.github.io/posts/oklab/
• srgb_to_hsv
  Convert from sRGB to HSV.
• srgb_to_irgb
  Convert floating (0.0..1.0) RGB to integer (0..255) RGB. Simply clips values > 1.0 && < 0.0. Not RGB specific, but other formats typically aren’t represented as integers.
• srgb_to_lrgb
  Convert from sRGB to Linear Light RGB. https://en.wikipedia.org/wiki/SRGB#From_sRGB_to_CIE_XYZ
• xyz_to_lab
  Convert from CIE XYZ to CIE LAB. https://en.wikipedia.org/wiki/CIELAB_color_space#From_CIEXYZ_to_CIELAB
• xyz_to_lrgb
  Convert from CIE XYZ to Linear Light RGB. https://en.wikipedia.org/wiki/SRGB#From_CIE_XYZ_to_sRGB
• xyz_to_oklab
  Convert from CIE XYZ to OKLAB. https://bottosson.github.io/posts/oklab/