MATLAB Answers


Vectorize loop for image manipulation

Asked by Clay Swackhamer on 11 Mar 2017
Latest activity Commented on by Clay Swackhamer on 11 Mar 2017
I have a black and white image (Ibw), and I want to take a circular region from it, and place it on a white background. I made a mask with a one in each position where I want to keep the pixel in the image (inside the circular region).
The code below works... but I want to vectorize it if possible. Right now I step across the image pixels one at a time, and if the mask has a one, I put the value in the black and white image onto the white field (Ifield).
Ifield = ones(size(Ibw));
for i = 1:1:rows
for j = 1:1:cols
if mask(i,j) > 0
Ifield(i,j) = Ibw(i,j);
%Let Ifield keep its 1 (white)


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1 Answer

Answer by Image Analyst
on 11 Mar 2017
 Accepted Answer

Try this vectorized way:
Ifield = ones(size(Ibw));
Ifield(mask) = Ibw(mask);

  1 Comment

It works- and it's much easier on the eyes. Thanks ImageAnalyst!

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