Masking an RGB Image with Binary Mask

Question

I have an RGB image (M x N x 3 matrix) in MATLAB that I read in. I also have a Binary mask (M x N matrix) for the image, which is simply 0 for some region of interest and 1 ever

Answer 1

You are misusing imfilter() there. Imfilter is used for linear filter operations, not for masking or thresholding. Better do this:

z = image;          % image() is also a function. 
                    % Overwriting this name should be avoided

% Request user polygon for ROI
bw = roipoly(z);

% Create 3 channel mask
mask_three_chan = repmat(bw, [1, 1, 3]);

% Apply Mask
z(~mask_three_chan) = 0;

% Display
imshow(z);