Have you seen any function to create and display the 3D outline of CRT gamut in Lab coordinates? it would be interesting to be able to plot your

Lab = [L, a, b];

line (and any other created with this method) to test if it’s within the gamut.

Thanks
Matteo

and see if

what is the expected range for radius/chroma, 0-100?

Thank you,
Matteo

This submission seems very promising:
http://www.mathworks.com/matlabcentral/fileexchange/20757-drawing-color-histograms-and-color-clouds

Good luck

Matteo

I hade the same problem.
This happens – I think – because McNames assumed gray = 1/3 r + 1/3 g + 1/3 b. I read from Matlab help online that this is not how the conversion is done if you use rgb2gray, therefore the issue. For those that like me do not have the Image Processing Toolbox, you can see this by just applying the formula that rgb2gray uses which is G=(0.2989 * R + 0.5870 * G + 0.1140 * B).
For my purposes (display to normal and color-deficient people) it was sufficient to being able to switch back and forth between colorspiral and an equivalent grayscale, which I derived by using the average of R, G, and B, I=(R/3 + G/3 + B/3).
Unfortunately I have not come across a solution for printing. If I recall this was posted as a challenge in the puzzler too but there was never a solution.

I am working on a perceptual rainbow in Lab space. If and when I get to it I will share it.

Matteo

I am a master student working on color printing and gamut issues. I want to convert from RGB to Lab based on Adobe98 not based on sRGB. in makecform list there is not adobe just sRGB. Could you please let me know how to do that.

Thank you in advance