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
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mentation. This software is provided "as is" without
express or implied warranty.