Extensions/composite.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
  14 """
  15
  16 from AccessControl import Unauthorized
  17 from PIL.Image import new as newImage, open as imgopen, composite
  18 from cStringIO import StringIO
  19
  20 def compositeSolidColor(self, image, mask, color=0xffffff
  21                                                 , margin_right=0, margin_bottom=0
  22                                                 , margin_left=0, margin_top=0) :
  23         iw, ih = image.size
  24         if iw > 800 or ih > 800 :
  25                 raise Unauthorized, "You are not allowed to get an image larger than 800px"
  26         mask = imgopen(StringIO(mask))
  27         assert mask.mode=='L', "mask must be in L mode"
  28
  29         mw, mh = mask.size
  30
  31         if margin_right and margin_bottom :
  32                 box = (iw-mw - margin_right, ih-mh - margin_bottom, iw - margin_right, ih - margin_bottom)
  33         else :
  34                 box = (margin_left, margin_top, margin_left+mw, margin_top+mh)
  35
  36         tile = image.crop(box)
  37
  38         coloredImage = newImage('RGB', mask.size, color)
  39
  40         mergedImage = composite(coloredImage, tile, mask)
  41
  42         image.paste(mergedImage, box)
  43
  44
  45
  46 def outline(self, image, mask, distance=128
  47                         , margin_right=0, margin_bottom=0
  48                         , margin_left=0, margin_top=0) :
  49         iw, ih = image.size
  50         if iw > 800 or ih > 800 :
  51                 raise Unauthorized, "You are not allowed to get an image larger than 800px"
  52
  53         mask = imgopen(StringIO(mask))
  54         assert mask.mode=='L', "mask must be in L mode"
  55
  56         mw, mh = mask.size
  57         if margin_right and margin_bottom :
  58                 box = (iw-mw - margin_right, ih-mh - margin_bottom, iw - margin_right, ih - margin_bottom)
  59         else :
  60                 box = (margin_left, margin_top, margin_left+mw, margin_top+mh)
  61         tile = image.crop(box)
  62
  63         lumAverage = getLumAverage(tile)
  64
  65         gray = lumAverage - distance
  66         if gray < 0 :
  67                 gray = lumAverage + distance
  68
  69         assert gray <= 256
  70
  71         color = gray + (gray<<8) + (gray<<16)
  72         coloredImage = newImage('RGB', mask.size, color)
  73         mergedImage = composite(coloredImage, tile, mask)
  74
  75         image.paste(mergedImage, box)
  76
  77
  78
  79 def getLumHistogram(im) :
  80         histo = im.histogram()
  81         layers = len(histo) / 256
  82
  83         lHisto = []
  84         shifts = [i*256 for i in range(layers)]
  85
  86         for i in xrange(256) :
  87                 indexes = [n+i for n in shifts]
  88                 tot = reduce(lambda a, b : a+b, [histo[p] for p in indexes])
  89                 tot = int(round(tot / float(layers)))
  90                 lHisto.append(tot)
  91
  92         return lHisto
  93
  94
  95 def getLumAverage(im) :
  96         lHisto = getLumHistogram(im)
  97         L = 0
  98         for i in xrange(256) :
  99                 L += i * lHisto[i]
 100
 101         L = float(L) / reduce(lambda a,b : a + b, lHisto)
 102         L = round(L)
 103         L = int(L)
 104         return L