im_correl.m

f1=imread('Fig4.41(a).jpg');
subplot(311);imshow(f1,[]);
[p,q]=size(f1);
f2=zeros(p,q);
f=imread('Fig4.41(b).jpg');
s=size(f);
f2(1:s(1),1:s(2))=f;
subplot(312);imshow(f2,[]);

fr_f1=fft2(f1,200,200);
fr_f2=fft2(f2,200,200);
fr_2conj=conj(fr_f2);
fr=(1/40000)*fr_f1.*fr_2conj;
t=ifft2(fr,200,200);
subplot(313);imshow(t,[]);

% ma=max(max(t));
% cord=find(t==ma);
% t(cord)=0;

% Do it using equation 4.6.32 or using spatial domain eqn