Generate a convolution kernel to be used with
pnmconvol
. See also:pnmconvol
. More information: https://netpbm.sourceforge.net/doc/pgmkernel.html.
pgmkernel width height > path/to/output.pgm
pgmkernel size > path/to/output.pgm
pgmkernel -weight value width height > path/to/output.pgm