Color Transform Icon

asColorTransform

A node that transforms a color from any input color model, to any output color model, respecting the color space definitions set in synColor CMS options. An option will be added later to override this, in a way similar to what is presently done in the luminance shader.

Parameters


Color Attributes

Input Color
The color being transformed.
Input Space

The input color space to transform from. It can be one of

Output Space

The output color space to transform to. It can be one of

  • RGB
  • HSV
  • HSL
  • CIE XYZ
  • CIE xyY
  • CIE 1976 L*a*b*
  • CIE 1976 L*u*v*
  • CIE 1976 LCh ab
  • CIE 1976 LCh uv

See also

The Colour Python colour science package for extensive information on the topic :cite:` [mansencal_thomas_2018_1175177]


Outputs

Result
The transformed color. For usability, the range of some spaces are remapped to the [0,1] range. As an example, the hue could be mapped to a greyscale texture, or if the space is set to CIE 1976 L*a*b*, the a variable would control the green/magenta oposition, while the b variable would control the blue/yellow oposition, with respective neutral/grey values at 0.5.

Screenshots

Some examples of color transformations.


Footnotes

[1]Hue, Saturation, Value color space, https://en.wikipedia.org/wiki/HSL_and_HSV
[2]Hue, Saturation, Lightness color space, https://en.wikipedia.org/wiki/HSL_and_HSV
[3]The CIE XYZ color space, https://en.wikipedia.org/wiki/CIE_1931_color_space
[4]CIE xyY, https://en.wikipedia.org/wiki/CIE_1931_color_space
[5]Cylindrical representation of the CIELAB color space, LCh ab co, https://en.wikipedia.org/wiki/Lab_color_space#Cylindrical_representation:_CIELCh_or_CIEHLC
[6]Cylindrical representation of the CIELUV color space, CIE LCh uv, https://en.wikipedia.org/wiki/Lab_color_space#Cylindrical_representation:_CIELCh_or_CIEHLC

References

[MMP+18]Thomas Mansencal, Michael Mauderer, Michael Parsons, Luke Canavan, Sean Cooper, Nick Shaw, Kevin Wheatley, Katherine Crowson, and Ofek Lev. Colour 0.3.11. February 2018. URL: https://doi.org/10.5281/zenodo.1175177, doi:10.5281/zenodo.1175177.
[McL76]K. McLAREN. Xiii—the development of the cie 1976 (l* a* b*) uniform colour space and colour-difference formula. Journal of the Society of Dyers and Colourists, 92(9):338–341, 1976. URL: http://dx.doi.org/10.1111/j.1478-4408.1976.tb03301.x, doi:10.1111/j.1478-4408.1976.tb03301.x.
[Poy12]Charles Poynton. Digital Video and HD: Algorithms and Interfaces. Morgan Kaufmann Publishers Inc., San Francisco, CA, USA, 2 edition, 2012. ISBN 9780123919267, 9780123919328.