在matlab中找到黑色像素位置

Question

i want to find black pixel positions and save them. i used this code.

I= imread('bin_ecgm.png');

 imshow(I);

  [r c] =size(I);

   for j=1:c

    for i=1:r

        if(I(i,j)==1)
        [i j]    
        end
    end
end

how to store black pixel positions

Answer 1

usually black pixels are I( ii, jj ) == 0 ... you can do that without a loop

[ii jj] = find( I == 0 ); % or I == 1 if you insist...

PS,
It is best not to use i and j as variable names in Matlab .