import math
import operator
-import Image
-import ImageChops
-import ImageEnhance
+from PIL import Image
+from PIL import ImageChops
+from PIL import ImageEnhance
+from PIL import ImageFilter
thumb_size = 320, 320
+gaussian_kernel = ImageFilter.Kernel((3, 3), [1, 2, 1, 2, 4, 2, 1, 2, 1], 16)
-def _compare(ref_image, src_image, delta_image):
- import subprocess
- p = subprocess.Popen([
- 'compare',
- '-metric', 'AE',
- '-fuzz', '%u%%' % options.fuzz,
- '-dissimilarity-threshold', '1',
- ref_image, src_image, delta_image
- ], stderr=subprocess.PIPE)
- _, stderr = p.communicate()
- try:
- return int(stderr)
- except ValueError:
- return 0xffffffff
+class Comparer:
+ '''Image comparer.'''
+ def __init__(self, ref_image, src_image, alpha = False):
+ if isinstance(ref_image, basestring):
+ self.ref_im = Image.open(ref_image)
+ else:
+ self.ref_im = ref_image
-def compare(ref_image, src_image, delta_image):
- ref_im = Image.open(ref_image)
- src_im = Image.open(src_image)
+ if isinstance(src_image, basestring):
+ self.src_im = Image.open(src_image)
+ else:
+ self.src_im = src_image
- ref_im = ref_im.convert('RGB')
- src_im = src_im.convert('RGB')
+ # Ignore
+ if not alpha:
+ self.ref_im = self.ref_im.convert('RGB')
+ self.src_im = self.src_im.convert('RGB')
- diff = ImageChops.difference(src_im, ref_im)
+ self.diff = ImageChops.difference(self.src_im, self.ref_im)
- mask = ImageEnhance.Brightness(diff).enhance(100.0/options.fuzz)
- mask = mask.convert('L')
+ def size_mismatch(self):
+ return self.ref_im.size != self.src_im.size
- lowlight = Image.new('RGB', src_im.size, (0xff, 0xff, 0xff))
- highlight = Image.new('RGB', src_im.size, (0xf1, 0x00, 0x1e))
- delta_im = Image.composite(highlight, lowlight, mask)
+ def write_diff(self, diff_image, fuzz = 0.05):
+ # make a difference image similar to ImageMagick's compare utility
+ mask = ImageEnhance.Brightness(self.diff).enhance(1.0/fuzz)
+ mask = mask.convert('L')
- delta_im = Image.blend(src_im, delta_im, 0xcc/255.0)
- delta_im.save(delta_image)
+ lowlight = Image.new('RGB', self.src_im.size, (0xff, 0xff, 0xff))
+ highlight = Image.new('RGB', self.src_im.size, (0xf1, 0x00, 0x1e))
+ diff_im = Image.composite(highlight, lowlight, mask)
- # See also http://effbot.org/zone/pil-comparing-images.htm
- # TODO: this is approximate due to the grayscale conversion
- h = diff.convert('L').histogram()
- ae = sum(h[255 * options.fuzz // 100 + 1 : 256])
- return ae
+ diff_im = Image.blend(self.src_im, diff_im, 0xcc/255.0)
+ diff_im.save(diff_image)
+
+ def precision(self, filter=False):
+ if self.size_mismatch():
+ return 0.0
+
+ diff = self.diff
+ if filter:
+ diff = diff.filter(gaussian_kernel)
+
+ # See also http://effbot.org/zone/pil-comparing-images.htm
+ h = diff.histogram()
+ square_error = 0
+ for i in range(1, 256):
+ square_error += sum(h[i : 3*256: 256])*i*i
+ rel_error = float(square_error*2 + 1) / float(self.diff.size[0]*self.diff.size[1]*3*255*255*2)
+ bits = -math.log(rel_error)/math.log(2.0)
+ return bits
+
+ def ae(self, fuzz = 0.05):
+ # Compute absolute error
+
+ if self.size_mismatch():
+ return sys.maxint
+
+ # TODO: this is approximate due to the grayscale conversion
+ h = self.diff.convert('L').histogram()
+ ae = sum(h[int(255 * fuzz) + 1 : 256])
+ return ae
def surface(html, image):
def is_image(path):
- return \
- path.endswith('.png') \
- and not path.endswith('.diff.png') \
- and not path.endswith('.thumb.png')
+ name = os.path.basename(path)
+ name, ext1 = os.path.splitext(name)
+ name, ext2 = os.path.splitext(name)
+ print name, ext1, ext2
+ return ext1 in ('.png', '.bmp') and ext2 not in ('.diff', '.thumb')
def find_images(prefix):
global options
optparser = optparse.OptionParser(
- usage="\n\t%prog [options] <ref_prefix> <src_prefix>",
- version="%%prog")
+ usage="\n\t%prog [options] <ref_prefix> <src_prefix>")
optparser.add_option(
'-o', '--output', metavar='FILE',
type="string", dest="output", default='index.html',
help="output filename [default: %default]")
optparser.add_option(
'-f', '--fuzz',
- type="int", dest="fuzz", default=5,
- help="fuzz percentage [default: %default]")
+ type="float", dest="fuzz", default=0.05,
+ help="fuzz ratio [default: %default]")
+ optparser.add_option(
+ '-a', '--alpha',
+ action="store_true", dest="alpha", default=False,
+ help="take alpha channel in consideration")
optparser.add_option(
'--overwrite',
action="store_true", dest="overwrite", default=False,
- help="overwrite")
+ help="overwrite images")
(options, args) = optparser.parse_args(sys.argv[1:])
or not os.path.exists(delta_image) \
or (os.path.getmtime(delta_image) < os.path.getmtime(ref_image) \
and os.path.getmtime(delta_image) < os.path.getmtime(src_image)):
- compare(ref_image, src_image, delta_image)
+
+ comparer = Comparer(ref_image, src_image, options.alpha)
+ comparer.write_diff(delta_image, fuzz=options.fuzz)
html.write(' <tr>\n')
surface(html, ref_image)
projects / apitrace / blobdiff