pnmalias

Apply antialiasing onto a PNM image. More information: https://netpbm.sourceforge.net/doc/pnmalias.html.

pnmalias path/to/input.pnm > path/to/output.ppm

pnmalias -bcolor background_color -fcolor foreground_color path/to/input.pnm > path/to/output.ppm

pnmalias -fonly path/to/input.pnm > path/to/output.ppm

pnmalias -balias path/to/input.pnm > path/to/output.ppm