Color wave length and hue

Question

Prashant Somani 2011-9-29

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链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/17011-color-wave-length-and-hue

编辑： Nikhil R. 2020-12-5

采纳的回答： Walter Roberson

Is there any method to get color hue from its wave length?

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Answer 1

Walter Roberson 2011-9-29

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https://ww2.mathworks.cn/matlabcentral/answers/17011-color-wave-length-and-hue#answer_22936

在 MATLAB Online 中打开

Hue = (650 - wavelength)*240/(650-475);

Extracted from: http://www.physics.uoguelph.ca/applets/Intro_physics/refraction/LightRefract.java

Note: the denominator consists of two seemingly arbitrary limits in the code. The 240 refers to the maximum hue value of 240 that is used in standard 8 bit Hue representation.

Visible light is about 400 to 700 nm, with 650 nm being the frequency of red. 475 is blue. Both indigo and violet fall below this limit, but the CIE model that defines the theoretical map of wavelength to hue has to treat colors in that range separately, and it could be that 475 nm is the effective limit for standard Hue calculation, perhaps requiring negative Hue (yes, that is possible in color theory, but not in standard 8 bit Hue representation.)

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Walter Roberson 2018-9-4

Sorry, I do not know, I did not write the code I linked to. I suspect the hue calculation given in that code might only be valid for colors in the range of red to blue, and that beyond that might start needing a different formula. The HSV and L*a*b* calculations are conditional based upon which component is strongest, and so calculating hue might get a bit complicated outside the noted range.

Nikhil R. 2020-12-5