%COLORDISTANCE Return distance in RG colorspace%%	cd = colordistance(rgb, rg)%%	The color image is converted to (r,g) coordinates and the distance%	of each pixel from the specificed coordinage rg is computed.%%	The output is an image with the same number of rows and columns as%	rgb where each pixel represents the correspoding color space distance.%%	This output image could be thresholded to determine color similarity.%% SEE ALSO:	colorseg%%	Copyright (c) Peter Corke, 2005  Machine Vision Toolbox for Matlab% Peter Corke 2005%function s = colordistance(im, rg)	% convert image to (r,g) coordinates	rgb = sum(im, 3);	r = im(:,:,1) ./ rgb;	g = im(:,:,2) ./ rgb;	% compute the Euclidean color space distance	d = (r - rg(1)).^2 + (g - rg(2)).^2;	if nargout == 0,		idisp(d)	else		s = d;	end