function F=edpm_yalin(Ea,Ed);
%
% Function EDPM : Edge detector performance measure function. 
% 	          Calculates for a given edge image the false alarm 
%		  count, miss count and figure of merit (F) values.   		 	
%
%  
%    Input(s)... Ea : Actual edge image     	
%		 Ed : Detected edge image.
%
%    Output(s).. fac: False alarm count
%		 msc: miss count
%		 F  : Figure of merit
%
%
%   Written by A.Latif  10-11-97
Ea=double(Ea);
Ed=double(Ed);

[N,M]=size(Ea);
if [N,M]~=size(Ed) 
  error('Actual and detected edge image sizes must be same');
end;
a=0.1; % edge shift penalty constant;
fac=length(find((Ea-Ed)==-1)); % False Alarm Count
msc=length(find((Ea-Ed)==1));  % Miss Count
Na=sum(sum(Ea));Nd=sum(sum(Ed));
c=1/max(Na,Nd);
[ia,ja]=find(Ea==1);
for l=1:Na
  Aes(l)=Ed(ia(l),ja(l));
end;
mi=ia(find(Aes==0));
mj=ja(find(Aes==0));
F=c*sum(Aes);
for k=1:length(mi) 
  n1=0;n2=0;m1=0;m2=0; 
  while sum(sum(Ed(mi(k)-n1:mi(k)+n2,mj(k)-m1:mj(k)+m2)))<1
    if mi(k)-n1>1 n1=n1+1;end;  
    if mi(k)+n2<N n2=n2+1;end;  
    if mj(k)-m1>1 m1=m1+1;end;  
    if mj(k)+m2<M m2=m2+1;end;  
  end;
  di=max([n1 n2 m1 m2]);
  F=F+c/(1+a*di^2);
end;