Lib/plat-irix6/torgb.py

   1 # Convert "arbitrary" image files to rgb files (SGI's image format).
   2 # Input may be compressed.
   3 # The uncompressed file type may be PBM, PGM, PPM, GIF, TIFF, or Sun raster.
   4 # An exception is raised if the file is not of a recognized type.
   5 # Returned filename is either the input filename or a temporary filename;
   6 # in the latter case the caller must ensure that it is removed.
   7 # Other temporary files used are removed by the function.
   8
   9 import os
  10 import tempfile
  11 import pipes
  12 import imghdr
  13
  14 table = {}
  15
  16 t = pipes.Template()
  17 t.append('fromppm $IN $OUT', 'ff')
  18 table['ppm'] = t
  19
  20 t = pipes.Template()
  21 t.append('(PATH=$PATH:/ufs/guido/bin/sgi; exec pnmtoppm)', '--')
  22 t.append('fromppm $IN $OUT', 'ff')
  23 table['pnm'] = t
  24 table['pgm'] = t
  25 table['pbm'] = t
  26
  27 t = pipes.Template()
  28 t.append('fromgif $IN $OUT', 'ff')
  29 table['gif'] = t
  30
  31 t = pipes.Template()
  32 t.append('tifftopnm', '--')
  33 t.append('(PATH=$PATH:/ufs/guido/bin/sgi; exec pnmtoppm)', '--')
  34 t.append('fromppm $IN $OUT', 'ff')
  35 table['tiff'] = t
  36
  37 t = pipes.Template()
  38 t.append('rasttopnm', '--')
  39 t.append('(PATH=$PATH:/ufs/guido/bin/sgi; exec pnmtoppm)', '--')
  40 t.append('fromppm $IN $OUT', 'ff')
  41 table['rast'] = t
  42
  43 t = pipes.Template()
  44 t.append('djpeg', '--')
  45 t.append('(PATH=$PATH:/ufs/guido/bin/sgi; exec pnmtoppm)', '--')
  46 t.append('fromppm $IN $OUT', 'ff')
  47 table['jpeg'] = t
  48
  49 uncompress = pipes.Template()
  50 uncompress.append('uncompress', '--')
  51
  52
  53 class error(Exception):
  54         pass
  55
  56 def torgb(filename):
  57         temps = []
  58         ret = None
  59         try:
  60                 ret = _torgb(filename, temps)
  61         finally:
  62                 for temp in temps[:]:
  63                         if temp != ret:
  64                                 try:
  65                                         os.unlink(temp)
  66                                 except os.error:
  67                                         pass
  68                                 temps.remove(temp)
  69         return ret
  70
  71 def _torgb(filename, temps):
  72         if filename[-2:] == '.Z':
  73                 fname = tempfile.mktemp()
  74                 temps.append(fname)
  75                 sts = uncompress.copy(filename, fname)
  76                 if sts:
  77                         raise error, filename + ': uncompress failed'
  78         else:
  79                 fname = filename
  80         try:
  81                 ftype = imghdr.what(fname)
  82         except IOError, msg:
  83                 if type(msg) == type(()) and len(msg) == 2 and \
  84                         type(msg[0]) == type(0) and type(msg[1]) == type(''):
  85                         msg = msg[1]
  86                 if type(msg) is not type(''):
  87                         msg = `msg`
  88                 raise error, filename + ': ' + msg
  89         if ftype == 'rgb':
  90                 return fname
  91         if ftype is None or not table.has_key(ftype):
  92                 raise error, \
  93                         filename + ': unsupported image file type ' + `ftype`
  94         temp = tempfile.mktemp()
  95         sts = table[ftype].copy(fname, temp)
  96         if sts:
  97                 raise error, filename + ': conversion to rgb failed'
  98         return temp