how to find distance of each pixel of image from center of image

I am interested to find the distance between each pixel of an image with respect to center of image. It is independent of gray level.

Answer 1

[Jan]

If your image has 640 x 480 pixels, and the center is at the pixel 320 / 240:

img = rand(480, 640);
y = 1:size(img, 1);
x = 1:size(img, 2);
c = [240, 320];
D = sqrt((y.' - c(1)) .^ 2 + (x - c(2)) .^ 2);  % >= R2016b

With older Matlab versions:

D = sqrt(bsxfun(@plus, (y.' - c(1)) .^ 2, (x - c(2)) .^ 2));

This is the distance measured in pixels.

[Pratik Oak]

Thank you very much

I got it now

[Jan]

amir baig found a typo: "qplus" -> "@plus".

Thanks!