From e9fcdcf14a99f5cb4729abb7bbf7817d7aa59d18 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Jos=C3=A9=20Fonseca?= Date: Wed, 14 Dec 2011 23:18:49 +0000 Subject: [PATCH] Filter to mitigate rasterization differences. --- scripts/snapdiff.py | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/scripts/snapdiff.py b/scripts/snapdiff.py index ddc2bf7..bf37686 100755 --- a/scripts/snapdiff.py +++ b/scripts/snapdiff.py @@ -39,10 +39,12 @@ import operator 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) class Comparer: '''Image comparer.''' @@ -80,12 +82,16 @@ class Comparer: diff_im = Image.blend(self.src_im, diff_im, 0xcc/255.0) diff_im.save(diff_image) - def precision(self): + 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 = self.diff.histogram() + h = diff.histogram() square_error = 0 for i in range(1, 256): square_error += sum(h[i : 3*256: 256])*i*i -- 2.7.4