Man page 1 : pnmenlarge

pnmenlarge - read a portable anymap and enlarge it N times

pnmenlarge N [ pnmfile ]

Reads a portable anymap as input. Replicates its pixels Ntimes, and produces a portable anymap as output.

pnmenlargecan only enlarge by integer factors. The slower but more general pnmscalecan enlarge or reduce by arbitrary factors, and pbmreducecan reduce by integer factors, but only for bitmaps.

If you enlarge by a factor of 3 or more, you should probably add a pnmsmoothstep; otherwise, you can see the original pixels in the resulting image.

pbmreduce(1), pnmscale(1), pnmsmooth(1), pnm(5)

Copyright (C) 1989 by Jef Poskanzer.