MATLAB: Logical indexing 3d array with 2d array

logical indexing

how can i set the values of my matrix to a certain rgb value given a mask ?
image_a;   %(640x480x3) uint8
mask;      %(640x480x1) logical mat
image_a(mask) = cv::RGB(255,200,0);

Best Answer

Exactly like I showed you in your earlier identical question (Method 2):
 A(mask(:,:,[1,1,1])) = value
If you have a single RGB value that you want to allocate to the masked points then use imoverlay from the image processing toolbox:
 B = imoverlay(A,mask,rgb)
If you do not have the image processing toolbox then you can get much the same effect by using bsxfun:
 B = bsxfun(@times,A,~mask) + bsxfun(@times,rgb,mask)
where rgb is a single triple of size 1*1*3, and both mask and rgb are of the same class as the image A.
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