www.pudn.com > snake_program.rar > dt.m

function D = dt(B) 
% DT apply Eucledian distance transform 
%    D = dt(B) compute the Eucledian distance transform of B 
%    B must be a binary map.  
% 
% NOTE: this is not an efficient way to implement distance transform.  
%    If one is interested in using DT, one may want to implement its 
%    own DT.  
 
%    Chenyang Xu and Jerry L. Prince 6/17/97 
%    Copyright (c) 1996-97 by Chenyang Xu and Jerry L. Prince 
 
[i,j] = find(B); 
 
[n,m] = size(B); 
for x = 1:n, 
    for y = 1:m, 
        dx = i-x; 
        dy = j-y; 
        dmag = sqrt(dx.*dx+dy.*dy); 
	D(x,y) = min(dmag); 
    end 
end