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ALPHAMASK: semi-transparent image overlay

version 1.0.0.0 (1.77 KB) by Andrew Davis
Overlay image with semi-transparent mask and return handle

9 Downloads

Updated 06 Feb 2012

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ALPHAMASK: Overlay image with semi-transparent mask

Overlays a semi-transparent mask over an image. By default the
currently displayed figure is overlain.
Options include overlay colour and opacity.
Returns a handle to the overlay mask.

Usage:
hOVM = alphaMask(bwMask, [colour, transparency, axHandle])
bwMask: logical matrix representing mask
colour: vector of three rgb values in range [0, 1] (optional; default [0 0 1])
transparency: scalar in range [0, 1] representing overlay opacity (optional; default 0.6)
axHandle: handle to axes on which to operate (optional; default current axes)
hOVM: handle to overlay image is returned

Example:
figure;
I = peaks(200);
bwMask = eye(200);
imshow(I, [], 'Colormap', hot);
alphamask(bwMask, [0 0 1], 0.5);

See also IMSHOW, CREATEMASK

Comments and Ratings (6)

Thank you davis, that's exactly what i'm looking for

David

Works.

Zoé

Andrew Davis

Thanks for the comment, Scott. I was using the square brackets to indicate that those arguments are optional, but I can see how it could be construed to mean that the last three arguments should be given as a single vector. Maybe alphamask(bwMask, [colour], [transparency], [axHandle]) would be more clear...

Scott

Great function. FYI, you have a small typo in your usage comments. Line 10 should read:
% hOVM = alphamask(bwMask, [colour], transparency, axHandle)

Lili

MATLAB Release Compatibility
Created with R2011a
Compatible with any release
Platform Compatibility
Windows macOS Linux
Acknowledgements

Inspired by: Image overlay