MATLAB: Find indices of a binary matrix depicting a circular disk in the clockwise direction

Question

I have a binary matrix of a circular disk. I need to find the indices of all the ones in the matrix. However, I am trying to find it sequentially in the clockwise/anticlockwise direction. I have used the find fuction. But that gives me the indices in the row by row or column by column sequence rather than circumferentially. Any help will be appreciated

Answer 1

[rows, cols] = find(YourImage);
%find the centroid
rowcent = mean(rows);
colcent = mean(cols);
%convert to polar
[theta, rho] = cart2pol(cols - colcent, rows - rowcent);
%sort in polar
[~, sortidx] = sort(theta);
%reorder x y
sort_rows = rows(sortidx);
sort_cols = cols(sortidx);