% grapple2.m applies median filters until no further change occurs

G = imread('grapple.gif');             % read the .gif file
G = G(300:700,1:401);                  % only deal with a small part of image
clf
subplot(3,2,1)
imshow(G,[0 1]);                       % display the image with 2 gray levels
title('Original image')
drawnow
for i=2:6,
  q = 2*i-1;                           % size of the window to filter with
  c = 1;                               % number of iterations
  H = G;
  J = medfilt2(H,[q q],'symmetric');
  while sum(sum(H~=J)) > 0,            % while changes occur
    c = c + 1;
    H = J;
    J = medfilt2(J,[q q],'symmetric'); % filter again
  end
  K(:,:,i) = J;                        % store the final images
  subplot(3,2,i)
  imshow(J,[0 1]);
  title([int2str(q) ' by ' int2str(q) ' median filter, applied ' int2str(c) ' times']);
  drawnow
end