2 ##########################################################################
4 # Copyright 2011 Jose Fonseca
5 # Copyright 2008-2009 VMware, Inc.
8 # Permission is hereby granted, free of charge, to any person obtaining a copy
9 # of this software and associated documentation files (the "Software"), to deal
10 # in the Software without restriction, including without limitation the rights
11 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
12 # copies of the Software, and to permit persons to whom the Software is
13 # furnished to do so, subject to the following conditions:
15 # The above copyright notice and this permission notice shall be included in
16 # all copies or substantial portions of the Software.
18 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
21 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
22 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
23 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
26 ##########################################################################/
29 '''Snapshot (image) comparison script.
40 from PIL import ImageChops
41 from PIL import ImageEnhance
42 from PIL import ImageFilter
47 gaussian_kernel = ImageFilter.Kernel((3, 3), [1, 2, 1, 2, 4, 2, 1, 2, 1], 16)
52 def __init__(self, ref_image, src_image, alpha = False):
53 if isinstance(ref_image, basestring):
54 self.ref_im = Image.open(ref_image)
56 self.ref_im = ref_image
58 if isinstance(src_image, basestring):
59 self.src_im = Image.open(src_image)
61 self.src_im = src_image
65 self.ref_im = self.ref_im.convert('RGB')
66 self.src_im = self.src_im.convert('RGB')
68 self.diff = ImageChops.difference(self.src_im, self.ref_im)
70 def size_mismatch(self):
71 return self.ref_im.size != self.src_im.size
73 def write_diff(self, diff_image, fuzz = 0.05):
74 if self.size_mismatch():
77 # make a difference image similar to ImageMagick's compare utility
78 mask = ImageEnhance.Brightness(self.diff).enhance(1.0/fuzz)
79 mask = mask.convert('L')
81 lowlight = Image.new('RGB', self.src_im.size, (0xff, 0xff, 0xff))
82 highlight = Image.new('RGB', self.src_im.size, (0xf1, 0x00, 0x1e))
83 diff_im = Image.composite(highlight, lowlight, mask)
85 diff_im = Image.blend(self.src_im, diff_im, 0xcc/255.0)
86 diff_im.save(diff_image)
88 def precision(self, filter=False):
89 if self.size_mismatch():
94 diff = diff.filter(gaussian_kernel)
96 # See also http://effbot.org/zone/pil-comparing-images.htm
99 for i in range(1, 256):
100 square_error += sum(h[i : 3*256: 256])*i*i
101 rel_error = float(square_error*2 + 1) / float(self.diff.size[0]*self.diff.size[1]*3*255*255*2)
102 bits = -math.log(rel_error)/math.log(2.0)
105 def ae(self, fuzz = 0.05):
106 # Compute absolute error
108 if self.size_mismatch():
111 # TODO: this is approximate due to the grayscale conversion
112 h = self.diff.convert('L').histogram()
113 ae = sum(h[int(255 * fuzz) + 1 : 256])
117 def surface(html, image):
119 name, ext = os.path.splitext(image)
120 thumb = name + '.thumb' + ext
121 if os.path.exists(image) \
122 and (not os.path.exists(thumb) \
123 or os.path.getmtime(thumb) < os.path.getmtime(image)):
124 im = Image.open(image)
125 imageWidth, imageHeight = im.size
126 if imageWidth <= thumbSize and imageHeight <= thumbSize:
127 if imageWidth >= imageHeight:
128 imageHeight = imageHeight*thumbSize/imageWidth
129 imageWidth = thumbSize
131 imageWidth = imageWidth*thumbSize/imageHeight
132 imageHeight = thumbSize
133 html.write(' <td><img src="%s" width="%u" height="%u"/></td>\n' % (image, imageWidth, imageHeight))
136 im.thumbnail((thumbSize, thumbSize))
140 html.write(' <td><a href="%s"><img src="%s"/></a></td>\n' % (image, thumb))
144 name = os.path.basename(path)
145 name, ext1 = os.path.splitext(name)
146 name, ext2 = os.path.splitext(name)
147 return ext1 in ('.png', '.bmp') and ext2 not in ('.diff', '.thumb')
150 def find_images(prefix):
151 if os.path.isdir(prefix):
154 prefix_dir = os.path.dirname(prefix)
157 for dirname, dirnames, filenames in os.walk(prefix_dir, followlinks=True):
158 for filename in filenames:
159 filepath = os.path.join(dirname, filename)
160 if filepath.startswith(prefix) and is_image(filepath):
161 images.append(filepath[len(prefix):])
169 optparser = optparse.OptionParser(
170 usage="\n\t%prog [options] <ref_prefix> <src_prefix>")
171 optparser.add_option(
173 action="store_true", dest="verbose", default=False,
174 help="verbose output")
175 optparser.add_option(
176 '-o', '--output', metavar='FILE',
177 type="string", dest="output", default='index.html',
178 help="output filename [default: %default]")
179 optparser.add_option(
181 type="float", dest="fuzz", default=0.05,
182 help="fuzz ratio [default: %default]")
183 optparser.add_option(
185 action="store_true", dest="alpha", default=False,
186 help="take alpha channel in consideration")
187 optparser.add_option(
189 action="store_true", dest="overwrite", default=False,
190 help="overwrite images")
191 optparser.add_option(
193 action="store_true", dest="show_all", default=False,
194 help="show all images, including similar ones")
196 (options, args) = optparser.parse_args(sys.argv[1:])
199 optparser.error('incorrect number of arguments')
204 ref_images = find_images(ref_prefix)
205 src_images = find_images(src_prefix)
206 images = list(set(ref_images).intersection(set(src_images)))
210 html = open(options.output, 'wt')
213 html.write('<html>\n')
214 html.write(' <body>\n')
215 html.write(' <table border="1">\n')
216 html.write(' <tr><th>File</th><th>%s</th><th>%s</th><th>Δ</th></tr>\n' % (ref_prefix, src_prefix))
219 ref_image = ref_prefix + image
220 src_image = src_prefix + image
221 root, ext = os.path.splitext(src_image)
222 delta_image = "%s.diff.png" % (root, )
223 if os.path.exists(ref_image) and os.path.exists(src_image):
225 sys.stdout.write('Comparing %s and %s ...' % (ref_image, src_image))
226 comparer = Comparer(ref_image, src_image, options.alpha)
227 match = comparer.ae(fuzz=options.fuzz) == 0
236 sys.stdout.write(' %s\n' % (result,))
237 html.write(' <tr>\n')
238 html.write(' <td bgcolor="%s"><a href="%s">%s<a/></td>\n' % (bgcolor, ref_image, image))
239 if not match or options.show_all:
240 if options.overwrite \
241 or not os.path.exists(delta_image) \
242 or (os.path.getmtime(delta_image) < os.path.getmtime(ref_image) \
243 and os.path.getmtime(delta_image) < os.path.getmtime(src_image)):
244 comparer.write_diff(delta_image, fuzz=options.fuzz)
245 surface(html, ref_image)
246 surface(html, src_image)
247 surface(html, delta_image)
248 html.write(' </tr>\n')
250 html.write(' </table>\n')
251 html.write(' </body>\n')
252 html.write('</html>\n')
257 if __name__ == '__main__':