filling regions of matrix

Hi have a matrix.

I =

     0     0     0     1
     0     0     1     0
     0     1     0     0
     1     0     0     0
     0     1     0     0
     0     0     1     0
     0     0     0     1

Here ones in the matrix has divided the matrix in 3 regions.Is it possible to have the following type of output:

I =

     2     2     2     1
     2     2     1     1
     2     1     1     1
     1     1     1     1
     3     1     1     1
     3     3     1     1
     3     3     3     1
Thanks

Answer 1

[Andrei Bobrov]

Iout = bwlabel(~cumsum(I,2))+1

[Oleg Komarov]

great! +1

[Mohammad Golam Kibria]

Thanks

Answer 2

[the cyclist]

There might be more efficient ways, but this will get the job done. I hope I didn't just do your homework for you.

I = [0     0     0     1; ...
     0     0     1     0; ...
     0     1     0     0; ...
     1     0     0     0; ...
     0     1     0     0; ...
     0     0     1     0; ...
     0     0     0     1];

[M,N] = size(I);

J = I;

for nj = 1:N

      % Find the ones in this column. Algorithm OK even if there's only one of them.
      firstOne = find(I(:,nj),1,'first');
      lastOne  = find(I(:,nj),1,'last');

      J(1:firstOne-1,    nj) = 2;
      J(firstOne:lastOne,nj) = 1;
      J(lastOne+1:end,   nj) = 3;

end

J

[Mohammad Golam Kibria]

This also works fine.