Displaying a color gamut surface -- Old Code does not work in r2021b ?

I found this article Displaying a color gamut surface » Steve on Image Processing with MATLAB - MATLAB & Simulink (mathworks.com)

As I tried to step through the code, I stumbled on this error :

Error in Z_Boundary_sRGB (line 13)

trisurf(k,a,b,L,'FaceColor','interp','FaceVertexCData',rgb,'EdgeColor','none')

The web site page, down in the comment section, refers to a 'fix' for 2014b and later :

set(groot,'DefaultFigureColormap',map)

Since I'm using R2021b, I figured I'll add the code but I still got the error. I'll keep searching at my end... but here's, in case...

[r,g,b] = meshgrid(linspace(0,1,50));

rgb = [r(:), g(:), b(:)];

lab = rgb2lab(rgb);

a = lab(:,2);

b = lab(:,3);

L = lab(:,1);

k = boundary(a,b,L);

trisurf(k,a,b,L,'FaceColor','interp','FaceVertexCData',rgb,'EdgeColor','none')

xlabel('a*')

ylabel('b*')

zlabel('L*')

axis([-110 110 -110 110 0 100])

view(-10,35)

axis equal

title('sRGB gamut surface in L*a*b* space')

I get the concept of a 3D boundary but I confess I'm at loss as to explain what's going on in the trisurf function.

Any help is appreciated :-)

Answer 1

[Roger Breton]

Never mind! I inadvertently saved a snippet of code under the name trisurf.m in the current directory. So when Matlab executed the script, of course, MY trisurf.m function took precedence ove the built-in, "real" trisurf.m function. Egg on my face... I'll learn to better read error messages in the future... Needless to say, as soon as I renamed my code snippet, the script worked flawlessly, as it pulled the "original" trisurf code...

Boy! Let that be a lesson...