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 # make a difference image similar to ImageMagick's compare utility
75 mask = ImageEnhance.Brightness(self.diff).enhance(1.0/fuzz)
76 mask = mask.convert('L')
78 lowlight = Image.new('RGB', self.src_im.size, (0xff, 0xff, 0xff))
79 highlight = Image.new('RGB', self.src_im.size, (0xf1, 0x00, 0x1e))
80 diff_im = Image.composite(highlight, lowlight, mask)
82 diff_im = Image.blend(self.src_im, diff_im, 0xcc/255.0)
83 diff_im.save(diff_image)
85 def precision(self, filter=False):
86 if self.size_mismatch():
91 diff = diff.filter(gaussian_kernel)
93 # See also http://effbot.org/zone/pil-comparing-images.htm
96 for i in range(1, 256):
97 square_error += sum(h[i : 3*256: 256])*i*i
98 rel_error = float(square_error*2 + 1) / float(self.diff.size[0]*self.diff.size[1]*3*255*255*2)
99 bits = -math.log(rel_error)/math.log(2.0)
102 def ae(self, fuzz = 0.05):
103 # Compute absolute error
105 if self.size_mismatch():
108 # TODO: this is approximate due to the grayscale conversion
109 h = self.diff.convert('L').histogram()
110 ae = sum(h[int(255 * fuzz) + 1 : 256])
114 def surface(html, image):
116 name, ext = os.path.splitext(image)
117 thumb = name + '.thumb' + ext
118 if os.path.exists(image) \
119 and (not os.path.exists(thumb) \
120 or os.path.getmtime(thumb) < os.path.getmtime(image)):
121 im = Image.open(image)
122 im.thumbnail(thumb_size)
126 html.write(' <td><a href="%s"><img src="%s"/></a></td>\n' % (image, thumb))
130 name = os.path.basename(path)
131 name, ext1 = os.path.splitext(name)
132 name, ext2 = os.path.splitext(name)
133 return ext1 in ('.png', '.bmp') and ext2 not in ('.diff', '.thumb')
136 def find_images(prefix):
137 if os.path.isdir(prefix):
140 prefix_dir = os.path.dirname(prefix)
143 for dirname, dirnames, filenames in os.walk(prefix_dir, followlinks=True):
144 for filename in filenames:
145 filepath = os.path.join(dirname, filename)
146 if filepath.startswith(prefix) and is_image(filepath):
147 images.append(filepath[len(prefix):])
155 optparser = optparse.OptionParser(
156 usage="\n\t%prog [options] <ref_prefix> <src_prefix>")
157 optparser.add_option(
159 action="store_true", dest="verbose", default=False,
160 help="verbose output")
161 optparser.add_option(
162 '-o', '--output', metavar='FILE',
163 type="string", dest="output", default='index.html',
164 help="output filename [default: %default]")
165 optparser.add_option(
167 type="float", dest="fuzz", default=0.05,
168 help="fuzz ratio [default: %default]")
169 optparser.add_option(
171 action="store_true", dest="alpha", default=False,
172 help="take alpha channel in consideration")
173 optparser.add_option(
175 action="store_true", dest="overwrite", default=False,
176 help="overwrite images")
177 optparser.add_option(
179 action="store_true", dest="show_all", default=False,
180 help="show all images, including similar ones")
182 (options, args) = optparser.parse_args(sys.argv[1:])
185 optparser.error('incorrect number of arguments')
190 ref_images = find_images(ref_prefix)
191 src_images = find_images(src_prefix)
192 images = list(set(ref_images).intersection(set(src_images)))
196 html = open(options.output, 'wt')
199 html.write('<html>\n')
200 html.write(' <body>\n')
201 html.write(' <table border="1">\n')
202 html.write(' <tr><th>File</th><th>%s</th><th>%s</th><th>Δ</th></tr>\n' % (ref_prefix, src_prefix))
205 ref_image = ref_prefix + image
206 src_image = src_prefix + image
207 root, ext = os.path.splitext(src_image)
208 delta_image = "%s.diff.png" % (root, )
209 if os.path.exists(ref_image) and os.path.exists(src_image):
211 sys.stdout.write('Comparing %s and %s ...' % (ref_image, src_image))
212 comparer = Comparer(ref_image, src_image, options.alpha)
213 match = comparer.ae(fuzz=options.fuzz) == 0
222 sys.stdout.write(' %s\n' % (result,))
223 html.write(' <tr>\n')
224 html.write(' <td bgcolor="%s"><a href="%s">%s<a/></td>\n' % (bgcolor, ref_image, image))
225 if not match or options.show_all:
226 if options.overwrite \
227 or not os.path.exists(delta_image) \
228 or (os.path.getmtime(delta_image) < os.path.getmtime(ref_image) \
229 and os.path.getmtime(delta_image) < os.path.getmtime(src_image)):
230 comparer.write_diff(delta_image, fuzz=options.fuzz)
231 surface(html, ref_image)
232 surface(html, src_image)
233 surface(html, delta_image)
234 html.write(' </tr>\n')
236 html.write(' </table>\n')
237 html.write(' </body>\n')
238 html.write('</html>\n')
243 if __name__ == '__main__':