dog

 dog - difference of gaussians, Gb(sig1) - Gc(sig2)

 [ G, Gb, Gc ] = dog( sig1, sig2, r, th, N )

 Based on doog2.m
 Modified by Joel D. Miller, 10/6/05

 Original comments below:

 G=doog2(sig,r,th,N);
 Make difference of offset gaussians kernel
 theta is in degrees
 (see Malik & Perona, J. Opt. Soc. Amer., 1990)

 Example:
 >> imagesc(doog2(1,12,0,64,1))
 >> colormap(gray)

 by Serge Belongie