Convolving images? Non-interactive r.mask?

Hi

Can anybody tell me:

1) if there exist GRASS tools to convolve an image with a user defined
function: e.g. a Gaussian function with different standard deviations and
correlations varying from 0 to 1?

2) if there exist a version of r.mask that can be used non-intercatively?

Kim Dralle
kdr@dina.kvl.dk