pamenlarge

Enlarge a PAM image by duplicating pixels. See also: pbmreduce, pamditherbw, pbmpscale. More information: https://netpbm.sourceforge.net/doc/pamenlarge.html.

pamenlarge -scale N path/to/image.pam > path/to/output.pam

pamenlarge -xscale XN -yscale YN path/to/image.pam > path/to/output.pam