Matlab - How to mask a 3-D image using a binary image

Question

I have an image with red, green, blue channel and a binary version of the image.

What I want to do is concatenate those 2 images so that the binary image works as th

Answer 1

If you have a 3-D image I and a binary mask M, you can mask the irrelevant bits to zero either by multiplying the image by the mask:

I = bsxfun(@times, I, M);    

or by logical indexing:

I(~mask(:, :, ones(1, size(I, 3)))) = 0;

Answer 2

You can use the binary image as a logical index in the 3dim image. To zero all pixels in image that are zero in the binary mask, you can use the following code for each dimension: image(~mask)=0;

Answer 3

I'm not 100% sure I understood your problem, but here goes one suggestion:

Suppose rgbIm is your RGB image, and bwIm is your binary image;

You may try to "expand" your binary image to "3D" (so that its dimensions are consistent with the original RGB image) with the following line of code:

bwImAux = bwIm(:,:,[1 1 1]); 

And then perform a simple multiplication to "eliminate" all the pixels that are not ones in the binary image:

rgbImNew = rgbIm.*bwImAux;

Hope this helps.