Question

I am currently working on a function for averaging images in MATLAB. But I feel that the following lines could be much simpler, only I don’t know how.

    centroidImage(:,:,1) = double(centroidImage(:,:,1)) ./ alphaImage;
    centroidImage(:,:,2) = double(centroidImage(:,:,2)) ./ alphaImage;
    centroidImage(:,:,3) = double(centroidImage(:,:,3)) ./ alphaImage;

I get an error if I write it as:

    centroidImage = double(centroidImage) ./ alphaImage;

Because the dimensions don’t match (alphaImage is [y x] and centroidImage is [y x 3]). Is there not a simpler, more efficient way to iterate the dimensions of the centroidImage variable, without having to explicitly state them all one by one?

Answer 1

You can use bsxfun for this:

centroidImage = bsxfun(@rdivide,centroidImage,alphaImage);