Hue to wavelength mapping

Question

Is there an algorithm to find out the wavelength of the color given the hue value (between 0 degree to 360 degree). Is there any built-in function in MATLABfor the same?

Answer 1

I cant provide simple solution, but there is something you need to consider:

• The visible part of the spektrum is roughly between 380nm (UV-border) and 780nm (IR-border). But what you see (hue) depends on the cone-cells triggered. Above 660nm, the M-cone is not triggered at all, so everything between 660nm and 780nm is hue 0°.
• at 580nm you have yellow with hue 60°, the purest green is at about 535nm, so that is 120°, and the purest blue (240°) is at about 457nm.
• if you apply a linear function, yellow should be at 597nm - which it is not, so you'd need a more complex approach.
• above blue, the red cone still gets triggered until we see violet, but we wont reach red again on higher frequencies, so you cant go above approximately 300°.
• the hue range between 300° and 360° has no æquivalent in visible spektrum, it can only be simulated by mixing high frequency light (blue or violet) with red light, which results in something between magenta and red on the purple-line.