{"action":"created","issue":{"url":"https://api.github.com/repos/python-pillow/Pillow/issues/1098","labels_url":"https://api.github.com/repos/python-pillow/Pillow/issues/1098/labels{/name}","comments_url":"https://api.github.com/repos/python-pillow/Pillow/issues/1098/comments","events_url":"https://api.github.com/repos/python-pillow/Pillow/issues/1098/events","html_url":"https://github.com/python-pillow/Pillow/pull/1098","id":56657781,"number":1098,"title":"raise limits to skip webp alpha tests for libwebp <= 0.2.1","user":{"login":"frispete","id":1009685,"avatar_url":"https://avatars.githubusercontent.com/u/1009685?v=3","gravatar_id":"","url":"https://api.github.com/users/frispete","html_url":"https://github.com/frispete","followers_url":"https://api.github.com/users/frispete/followers","following_url":"https://api.github.com/users/frispete/following{/other_user}","gists_url":"https://api.github.com/users/frispete/gists{/gist_id}","starred_url":"https://api.github.com/users/frispete/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/frispete/subscriptions","organizations_url":"https://api.github.com/users/frispete/orgs","repos_url":"https://api.github.com/users/frispete/repos","events_url":"https://api.github.com/users/frispete/events{/privacy}","received_events_url":"https://api.github.com/users/frispete/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":5,"created_at":"2015-02-05T11:22:06Z","updated_at":"2015-02-06T08:12:09Z","closed_at":null,"pull_request":{"url":"https://api.github.com/repos/python-pillow/Pillow/pulls/1098","html_url":"https://github.com/python-pillow/Pillow/pull/1098","diff_url":"https://github.com/python-pillow/Pillow/pull/1098.diff","patch_url":"https://github.com/python-pillow/Pillow/pull/1098.patch"},"body":"Dear Alex & friends,\r\n\r\nin my public openSUSE python repo, I maintain a huge stack of python related packages.\r\nOne nice thing about build serrvice is the possibility to build the packages for various distributions.\r\nFor my own needs, I limit them to openSUSE releases of various ages (as distribution independant build specifications are a great PITA, even for rpm based systems).\r\n\r\n    https://build.opensuse.org/package/show/home:frispete:python/python-Pillow\r\n\r\nThe one, that failed consistently was 12.3:\r\n\r\n[   98s] FAIL: Can we write a RGBA mode file to webp without error.\r\n[   98s] ----------------------------------------------------------------------\r\n[   98s] Traceback (most recent call last):\r\n[   98s]   File \"/home/abuild/rpmbuild/BUILD/Pillow-2.7.0/Tests/test_file_webp_alpha.py\", line 86, in test_write_rgba\r\n[   98s]     self.assert_image_similar(image, pil_image, 1.0)\r\n[   98s]   File \"/home/abuild/rpmbuild/BUILD/Pillow-2.7.0/Tests/helper.py\", line 105, in assert_image_similar\r\n[   98s]     ave_diff, epsilon))\r\n[   98s]\r\n\r\nObviously, this is due to a failing libwebp version.\r\nSince you already have a skip for version 0.1.3, question is, why not raise the limits for webp alpha tests. Side effect: the (rare) users of this lib are being warned that way, too, if they check  WebPDecoderBuggyAlpha."},"comment":{"url":"https://api.github.com/repos/python-pillow/Pillow/issues/comments/73200848","html_url":"https://github.com/python-pillow/Pillow/pull/1098#issuecomment-73200848","issue_url":"https://api.github.com/repos/python-pillow/Pillow/issues/1098","id":73200848,"user":{"login":"frispete","id":1009685,"avatar_url":"https://avatars.githubusercontent.com/u/1009685?v=3","gravatar_id":"","url":"https://api.github.com/users/frispete","html_url":"https://github.com/frispete","followers_url":"https://api.github.com/users/frispete/followers","following_url":"https://api.github.com/users/frispete/following{/other_user}","gists_url":"https://api.github.com/users/frispete/gists{/gist_id}","starred_url":"https://api.github.com/users/frispete/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/frispete/subscriptions","organizations_url":"https://api.github.com/users/frispete/orgs","repos_url":"https://api.github.com/users/frispete/repos","events_url":"https://api.github.com/users/frispete/events{/privacy}","received_events_url":"https://api.github.com/users/frispete/received_events","type":"User","site_admin":false},"created_at":"2015-02-06T08:12:09Z","updated_at":"2015-02-06T08:12:09Z","body":"On Donnerstag, 5. Februar 2015 22:17:14 wiredfool wrote:\n> I don't think that this is the right way to go about it.\n> \n> With webp 0.1.3, attempting to write a `RGBA` image as lossless webp\n> resulted in an `RGB` image, and reading a `RGBA` image failed completely.\n> \n> With 0.2.3, it appears that the algorithm works, but is a little different\n> from later versions. There is a little more variation from the expected\n> image. In this case it appears a difference of 3 rather than 1, which is\n> totally reasonable for a lossy format, especially with an early version\n> knowing that later versions do it better.\n\nSure, the primary question is, where do we want to draw the line concerning \nthe term buggy: do we want to test and handle those deviations specially, or \ndo we generally suppress _testing_ alpha channel mode results for these early \nlib versions. Nobody is going to test all released lib versions, hence it \npotentially ends in broken builds for certain environments. \n\nAnyway, I've reverted the fix, and supplied the former (IMHO uglier) approach.\nTest build with 5 different lib versions and two archs were successful.\n"}}