%ILOG	Laplacian of Gaussian kernel%%	L = ilog(w, sigma)%%	Return a Laplacian of Gaussian (LOG) kernel of width (2w+1) with%	the specified sigma.%% SEE ALSO:	zcross%%	Copyright (c) Peter Corke, 1999  Machine Vision Toolbox for Matlab% Peter Corke 1996function il = ilog(w, sigma)	[x,y] = meshgrid(-w:w, -w:w);	il = -1/(2*pi*sigma^4) * (2 - (x.^2 + y.^2)/sigma^2) .*  ...		exp(-(x.^2+y.^2)/(2*sigma^2));