problem one
derivation a)
the difference-of-gaussian is a function of x, y, sigma1 and k where:
- x,y - x,y-coord of point to be evaluated
- sigma - base standard deviation of the gaussian
- k - factor by which to multiply sigma to get other gaussian
or, equilvanetly
- x,y - x,y-coord of point to be evaluated
- sigma1 - base standard deviation of the first gaussian
- sigma2 - base standard deviation of the second gaussian