%ZNCC  Normalized cross correlation%%	m = zncc(w1, w2)%% Compute the zero-mean normalized cross-correlation between the two% equally sized image patches w1 and w2.  Result is in the range -1 to 1, with% 1 indicating identical pixel patterns.%% SEE ALSO:	isimilarity%%	Copyright (c) Peter Corke, 2002  Machine Vision Toolbox for Matlab% $Header: /home/autom/pic/cvsroot/image-toolbox/zncc.m,v 1.2 2005/10/23 11:08:21 pic Exp $% $Log: zncc.m,v $% Revision 1.2  2005/10/23 11:08:21  pic% Added doco.%% Revision 1.1.1.1  2002/05/26 10:50:25  pic% initial import%function m = zncc(w1, w2)	w1 = w1 - mean(w1(:));	w2 = w2 - mean(w2(:));	denom = sqrt( sum(sum(w1.^2))*sum(sum(w2.^2)) );	if denom < 1e-10,		m = 0;	else		m = sum(sum((w1.*w2))) / denom;	end