Create a "width" x "width" Gaussian kernel with stdev "sigma".
Create a normalized, automatically-sized Gaussian kernel.
Compute the smallest odd size for a Gaussian kernel with width "sigma".
Compute the smallest odd size for a Gaussian kernel with width "sigma". This uses the rule of thumb that a Gaussian kernel need only extend out 3 sigma from the center in all directions to be a good approximation.
Create a "width" x "width" Gaussian kernel with stdev "sigma".
Create a normalized, automatically-sized Gaussian kernel.
Estimate a "reasonable" odd size for kernel with "sigma".
Constructor for a simple symmetric Gaussian filter.