colour-science / colour

Colour Science for Python
https://www.colour-science.org
BSD 3-Clause "New" or "Revised" License
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Implement support for "NCS" colour notation system. #116

Open KelSolaar opened 9 years ago

KelSolaar commented 9 years ago

References

KelSolaar commented 9 years ago

I sent them an email to know if there are any papers supporting the conversion, we will see what they reply.

By the mean time I found the following implementation: http://jsfiddle.net/jdias/b3hEa/

I don't know if its correct though.

KelSolaar commented 9 years ago

Here is another implementation: http://people.sc.fsu.edu/~jburkardt/f_src/colors/colors.html

awehring commented 8 years ago

Warning: Don't use the jsfiddle code linked above (http://jsfiddle.net/jdias/b3hEa/). It is WRONG.

There is no simple way to calculate HSV or RGB values from NCS color codes. NCS (Natural Color System) fits to the human perception of color. It is derived from a large number of color perception tests with human subjects.

Therefore the conversion to the (technical) RGB or HSV color codes is complicated and needs large conversion tables and/or subtle functions.

The best way is to use the conversion of the NCS authors, but you have to pay for it: http://www.ncscolour.com/en/design-architecture/work-digitally-with-ncs/ncs-navigator/

MichaelMauderer commented 8 years ago

This article might be relevant: http://onlinelibrary.wiley.com/doi/10.1002/col.5080060303/abstract

KelSolaar commented 8 years ago

There seems to be a few formulas in the blurred preview of the paper. That issue is not really a priority anyway for now I guess.

KelSolaar commented 2 years ago

Relevant literature found by @bottosson:

awehring commented 2 years ago

Thank you for the literature references. It is worthwhile for anyone who wants to dive in.

There has been work to transform NCS to the CIELAB color system, from where you can go to RGB or other color representations. But as the abstract says "The data show that no simple relationship exists between the NCS and CIELAB systems."

"Transformation of NCS data into CIELAB colour space" https://onlinelibrary.wiley.com/doi/epdf/10.1002/col.5080110211

The paper is available online, but you have to pay for it or access it thru an universities library.