ppmを拡大・縮小する
ppmscale s [ppmfile] ppmscale -xsize|-width|-ysize|-height s [ppmfile] ppmscale -xscale|-yscale s [ppmfile] ppmscale -xscale|-xsize|-width s -yscale|-ysize|-height s [ppmfile]
ppmを入力ファイルとして読み込み、任意の大きさ(sの値は実数)に拡大・縮小して出力する。
出力は標準出力になる。
Copyright (C) 1989 by Jef Poskanzer. Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting docu- mentation. This software is provided "as is" without express or implied warranty.