Extensions/difference.py

   1 # -*- coding: utf-8 -*-
   2 ############################################################
   3 # Copyright © 2005-2008  Benoît PIN <benoit.pin@ensmp.fr>  #
   4 # Plinn - http://plinn.org                                 #
   5 #                                                          #
   6 # This program is free software; you can redistribute it   #
   7 # and/or modify it under the terms of the Creative Commons #
   8 # "Attribution-Noncommercial 2.0 Generic"                  #
   9 # http://creativecommons.org/licenses/by-nc/2.0/           #
  10 ############################################################
  11
  12 """
  13 $Id: difference.py 622 2008-11-16 23:38:18Z pin $
  14 $URL: http://svn.luxia.fr/svn/labo/projects/zope/Portfolio/trunk/Extensions/difference.py $
  15 """
  16 from AccessControl import Unauthorized
  17 from PIL.Image import new as newImage, open as imgopen, composite
  18 from PIL.ImageChops import difference
  19 from cStringIO import StringIO
  20
  21 def diffImage(self, image, image2, mask) :
  22         iw, ih = image.size
  23         if iw > 800 or ih > 800 :
  24                 raise Unauthorized, "You are not allowed to get an image larger than 800px"
  25
  26         mask = imgopen(StringIO(str(mask)))
  27         assert mask.mode=='L', "mask must be in L mode"
  28
  29         image2 = imgopen(StringIO(str(image2)))
  30         diffImage = difference(image, image2)
  31         mergedImage = composite(diffImage, image, mask)
  32
  33         box = (0,0) + mergedImage.size
  34
  35         image.paste(mergedImage, box)