# pnmsmooth > Smooth out a PNM image. > More information: . - Smooth out a PNM image using a convolution matrix of size 3x3: `pnmsmooth {{path/to/input.pnm}} > {{path/to/output.pnm}}` - Smooth out a PNM image using a convolution matrix of size width times height: `pnmsmooth -width {{width}} -height {{height}} {{path/to/input.pnm}} > {{path/to/output.pnm}}`