%SUBPIXEL  Subpixel interpolation of peak%%	[dxr, dyr] = subpixel(surf)%	[dxr, dyr] = subpixel(surf, dx, dy)%%  Given a 2-d surface refine the estimate of the peak to subpixel precision/%  The peak may be given by (dx, dy) or searched for.%% SEE ALSO: max2d, imatch, ihough%% Copyright (c) Peter Corke, 2001  Machine Vision Toolbox for Matlab% $Header: /home/autom/pic/cvsroot/image-toolbox/subpixel.m,v 1.1 2005/10/23 11:30:11 pic Exp $% $Log: subpixel.m,v $% Revision 1.1  2005/10/23 11:30:11  pic% Find peak to subpixel precision.%function [ddx,ddy] = subpixel(sim, dx, dy)	[nr,nc] = size(sim);	if nargin < 2,		[dx, dy] = max2d(sim);	end	ddx = 0;	ddy = 0;	if dx > 1 & dy > 1 & dx < (nc-1) & dy < (nr-1),		zn = sim(dy-1, dx);		zs = sim(dy+1, dx);		ze = sim(dy, dx+1);		zw = sim(dy, dx-1);		zc = sim(dy, dx);		ddx = 0.5*(ze-zw)/(2*zc-zw-ze);		ddy = 0.5*(zs-zn)/(2*zc-zn-zs);		if abs(ddx) < 1 & abs(ddy) > 1,			fprintf('interp too big %f %f\n', ddx, ddy);			ddx = 0;			ddy = 0;		end	end