Convolution Matrices for Astronomy

[Macavity]

Graphics software often contains a facility to input one's own convolution matrix. 

Indeed, if one has the patience to input the numbers, these work as indicated!

These are some examples from GIMP:

http://docs.gimp.org/en/plug-in-convmatrix.html

But beyond sharpening and blurring, there seems little of immediate relevance

to Astronomy... Unless you know differently! Seriously though (or simply as a

matter of interest!) has anyone come up with anything particularly exciting?

I suppose the same general question might apply to Wavelet matrices too?