% Exact Euclidean Distance Transform 
% Uses MATLAB image processing toolbox function bwdist() with default
% transform type
% M J de Smith, 19/5/03
% Ref:  Heinz Breu, Joseph Gil, David Kirkpatrick, and Michael Werman, 
%      "Linear Time Euclidean Distance Transform Algorithms," 
%       IEEE Transactions on Pattern Analysis and Machine Intelligence, 
%       vol. 17, no. 5 May 1995, pp. 529-533.

home;tic;
bw = zeros(101,101);
bw(50,50) = 1; 
D = bwdist(bw);

% shaded contour plot
whitebg([0 .4 .6]); rect = [100, 100, 650, 650];
figure(1); set(1,'Position',rect); str = datestr(now,0); 
contourf (D,8); colormap jet; alpha (.3); title([' Generated on: ',str]); xlabel('x-position'); ylabel ('y-position')
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