Both functions create a circularly symmetric laplacian of Gaussian mask. The
size of the mask is determined by the variable min_amplitude; if for instance
the value .1 is entered this means that the produced mask is clipped at values
within 10 persent of zero, and where the change between mask elements is less
The mask can be directly used with the vasari convolution
programs, the default offset set is 0.
The program uses the following equation: (from Handbook of Pattern Recognition
and image processing by Young and Fu, AP 1986 pages 220-221):