Volshow contrast or scaling the colormap

Is there a way to scale the colormap in volshow()? Similar to using 'caxis', [min max] for image()?

Answer 1

[Tim]

% Example volume
imcube = bsxfun(@power, rand(30, 30, 100),...
    permute(linspace(0, 8, 100), [3, 1, 2])).*...
    permute(linspace(1, 0, 100), [3, 1, 2]);

% Pick your color map
cmp = jet;

% Generate your volume object
V = volshow(imcube,...
    'Renderer', 'MaximumIntensityProjection',...
    'Colormap', cmp,...
    'BackgroundColor', [0, 0, 0]);

% Set your new color axis. This does the same thing as caxis normally
% would.

% % % % % % % % % % % % CAXIS EQUIVALENT % % % % % % % % % %
VAxis = [0.2, 1.5];
% % % % % % % % % % % % % % % % % % % % % % % % % % % % % % 

% Generate new scale
newscale = linspace(min(imcube(:)) - min(VAxis(:)),...
    max(imcube(:)) - min(VAxis(:)), size(cmp, 1))/diff(VAxis);
newscale(newscale < 0) = 0;
newscale(newscale > 1) = 1;

% Update colormap in volshow
V.Colormap = interp1(linspace(0, 1, size(cmp, 1)), cmp, newscale);

[Brittney Gorman]

This works! Thank you

Answer 2

[Pratyush Roy]

Hi,

Assuming that the colormap generation is being a bit difficult, one can use the "ColorMap" property of the volshow() function to manually generate a colormap.

The following documentation link might be of further help:

https://www.mathworks.com/help/images/ref/volshow.html#mw_383c687f-1551-423b-b3f2-0a725623b00b