%    Copyright (C) 1992, 1994 Aladdin Enterprises.  All rights reserved.%% This file is part of Ghostscript.%% Ghostscript is distributed in the hope that it will be useful, but% WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility% to anyone for the consequences of using it or for whether it serves any% particular purpose or works at all, unless he says so in writing.  Refer% to the Ghostscript General Public License for full details.%% Everyone is granted permission to copy, modify and redistribute% Ghostscript, but only under the conditions described in the Ghostscript% General Public License.  A copy of this license is supposed to have been% given to you along with Ghostscript so you can know your rights and% responsibilities.  It should be in a file named COPYING.  Among other% things, the copyright notice and this notice must be preserved on all% copies. % viewpbm.ps% Display a PBM/PGM/PPM file.  Currently only handles "raw" formats (P4-P6).% Requires the Level 2 `image' operator (to handle variable pixel widths). /s 100 string def/readmaxv { f s readline pop cvx exec /maxv exch def } bind def/readrow { 0 1 row length 1 sub { row exch f token pop put } for } bind def/read01			% <count> read01 <byte> { 0 exch { f read pop 48 xor dup 1 le { exch dup add add } { pop } ifelse } repeat } bind def/pdict 6 dict defpdict begin  /P1 [ { /maxv 1 def /rsize w 7 add 8 idiv def	  /wrem w 8 mod def          /ncomp 1 def /invert true def	}	{ 0 1 w 8 idiv { row exch 8 read01 put } for	  wrem 0 ne	   { row rsize 1 sub wrem read01 8 wrem sub bitshift put	   } if	  row	}      ] def  /P2 [ { readmaxv /rsize w def	  /ncomp 1 def /invert false def	}	{ readrow row }      ] def  /P3 [ { readmaxv /rsize w 3 mul def          /ncomp 3 def /invert false def /DeviceRGB setcolorspace	}	{ readrow row }      ] def  /P4 [ { /maxv 1 def /rsize w 7 add 8 idiv def	  /ncomp 1 def /invert true def	}	{ f row readstring pop }      ] def  /P5 [ { readmaxv /rsize w def	  /ncomp 1 def /invert false def	}	{ f row readstring pop }      ] def  /P6 [ { readmaxv /rsize w 3 mul def	  /ncomp 3 def /invert false def /DeviceRGB setcolorspace	}	{ f row readstring pop }      ] defend/viewpbm		% filename -> { (r) file /f exch def   f s readline pop cvn /pn exch def		% Pn   f s readline pop		% check for comment   (#) anchorsearch    { pop pop f s readline pop }   if   cvx exec /h exch def /w exch def   erasepage   /DeviceGray setcolorspace   pdict pn get dup /rprocs exch def     0 get exec			% sets maxv, rsize, ncomp, invert   /row rsize string def   % Scale the image (uniformly) to fit the page.   clippath pathbbox     dtransform exch abs exch abs min dup scale pop pop   20 dict begin		% image dictionary     /ImageType 1 def     /Width w def     /Height h def     /ImageMatrix [w 0 0 h neg 0 h] def     /BitsPerComponent maxv 1 add ln 2 ln div 0.0001 sub ceiling cvi def     /Decode [ 0 255 maxv div invert { exch } if ncomp 1 sub { 2 copy } repeat ] def     /DataSource rprocs 1 get def   currentdict end   image   showpage } def % If the program was invoked from the command line, run it now.[ shellarguments { counttomark 1 eq    { viewpbm    }    { cleartomark      (Usage: gs -- viewpbm.ps filename.p*m\n) print      ( e.g.: gs -- viewpbm.ps my.ppm\n) print flush      mark    }   ifelse }if pop