Question

I need to scan a (half of) binary image and store (or mark) only the position of first black pixel. I tried this out in matlab. But the code is displaying the positions of all the black pixels. My code is something like this.

I= imread('binary image');

imshow(I);

[r c] =size(I);

for j=1:c/2

    for i=1:r

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

Any suggestions to improve this…

Answer 1

You need to exit from the loops:

found = 0; % a flag
for j=1:c/2
  for i=1:r

    if(I(i,j)==1)
        [i j]
        found = 1;
        break; % stop the inner loop  
    end

    if (found)
        break; % stop the outer loop
    end
  end
end