This program calculates weight based on the bell-shaped Gaussian
curve. The weight is then applied to an image kernel in such a way as to
create a filter that will move a weighted average through the image. The
end result is a blurred image with reduced detail and noise. The Gaussian
function that determines the weight for all of the values in the kernel is
as follows
/ x^2+y^2 \
- | ----------- |
G(x,y) = 1 \ 2(STDDEV)^2 /
--------------- e^
2(pi)(STDDEV)^2

This formula creates a kernel that then runs through the image. The center of
the kernel is at (0,0). This means that a 3x3 boxcar will be of the form
The kernel coordinates
(-2,-2) (-1,-2) (0,-2) (1,-2) (2,-2)
(-2,-1) (-1,-1) (0,-1) (1,-1) (2,-1)
(-2, 0) (-1, 0) (0, 0) (1, 0) (2, 0)
(-2, 1) (-1, 1) (0, 1) (1, 1) (2, 1)
(-2, 2) (-1, 2) (0, 2) (1, 2) (2, 2)
The kernel values (approx)
1 4 7 4 1
4 16 26 16 4
7 26 41 26 7 x 1/273
4 16 26 16 4
1 4 7 4 1