{"action":"created","issue":{"url":"https://api.github.com/repos/pngwriter/pngwriter/issues/47","repository_url":"https://api.github.com/repos/pngwriter/pngwriter","labels_url":"https://api.github.com/repos/pngwriter/pngwriter/issues/47/labels{/name}","comments_url":"https://api.github.com/repos/pngwriter/pngwriter/issues/47/comments","events_url":"https://api.github.com/repos/pngwriter/pngwriter/issues/47/events","html_url":"https://github.com/pngwriter/pngwriter/issues/47","id":57358402,"number":47,"title":"Performance with very big Images","user":{"login":"ax3l","id":1353258,"avatar_url":"https://avatars.githubusercontent.com/u/1353258?v=3","gravatar_id":"","url":"https://api.github.com/users/ax3l","html_url":"https://github.com/ax3l","followers_url":"https://api.github.com/users/ax3l/followers","following_url":"https://api.github.com/users/ax3l/following{/other_user}","gists_url":"https://api.github.com/users/ax3l/gists{/gist_id}","starred_url":"https://api.github.com/users/ax3l/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ax3l/subscriptions","organizations_url":"https://api.github.com/users/ax3l/orgs","repos_url":"https://api.github.com/users/ax3l/repos","events_url":"https://api.github.com/users/ax3l/events{/privacy}","received_events_url":"https://api.github.com/users/ax3l/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/pngwriter/pngwriter/labels/performance","name":"performance","color":"dbea14"}],"state":"open","locked":false,"assignee":{"login":"ax3l","id":1353258,"avatar_url":"https://avatars.githubusercontent.com/u/1353258?v=3","gravatar_id":"","url":"https://api.github.com/users/ax3l","html_url":"https://github.com/ax3l","followers_url":"https://api.github.com/users/ax3l/followers","following_url":"https://api.github.com/users/ax3l/following{/other_user}","gists_url":"https://api.github.com/users/ax3l/gists{/gist_id}","starred_url":"https://api.github.com/users/ax3l/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ax3l/subscriptions","organizations_url":"https://api.github.com/users/ax3l/orgs","repos_url":"https://api.github.com/users/ax3l/repos","events_url":"https://api.github.com/users/ax3l/events{/privacy}","received_events_url":"https://api.github.com/users/ax3l/received_events","type":"User","site_admin":false},"milestone":{"url":"https://api.github.com/repos/pngwriter/pngwriter/milestones/2","html_url":"https://github.com/pngwriter/pngwriter/milestones/0.6.0","labels_url":"https://api.github.com/repos/pngwriter/pngwriter/milestones/2/labels","id":650657,"number":2,"title":"0.6.0","description":"Bigger changes than in 0.5.5 including some interface changes.","creator":{"login":"ax3l","id":1353258,"avatar_url":"https://avatars.githubusercontent.com/u/1353258?v=3","gravatar_id":"","url":"https://api.github.com/users/ax3l","html_url":"https://github.com/ax3l","followers_url":"https://api.github.com/users/ax3l/followers","following_url":"https://api.github.com/users/ax3l/following{/other_user}","gists_url":"https://api.github.com/users/ax3l/gists{/gist_id}","starred_url":"https://api.github.com/users/ax3l/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ax3l/subscriptions","organizations_url":"https://api.github.com/users/ax3l/orgs","repos_url":"https://api.github.com/users/ax3l/repos","events_url":"https://api.github.com/users/ax3l/events{/privacy}","received_events_url":"https://api.github.com/users/ax3l/received_events","type":"User","site_admin":false},"open_issues":21,"closed_issues":18,"state":"open","created_at":"2014-05-06T16:28:12Z","updated_at":"2016-05-24T16:33:47Z","due_on":null,"closed_at":null},"comments":5,"created_at":"2015-02-11T18:46:21Z","updated_at":"2016-05-26T08:18:38Z","closed_at":null,"body":"The write performance with very big images (above 4K) is pretty poor, see #46.\r\n\r\n- Does the internal memory alone harm the performance (#36), can it be optimized?\r\n- Do we call `libpng` inefficiently [for writes](https://github.com/pngwriter/pngwriter/blob/1461e599c03f639e3192ecb6e224a8bb0b69366b/src/pngwriter.cc#L1064)?\r\n  - What about using [png_write_flush/png_set_flush/png_write_row](http://www.libpng.org/pub/png/libpng-manual.txt)?\r\n  - Is `png_set_interlace_handling` [really disabled](https://github.com/pngwriter/pngwriter/blob/1461e599c03f639e3192ecb6e224a8bb0b69366b/src/pngwriter.cc#L1014) by default and what is the performance impact? Can one play with the `ADAM7` passes?\r\n  - play wit `png_set_filter`?\r\n  - use a better default for `setcompressionlevel`/`PNGWRITER_DEFAULT_COMPRESSION` (6) ? (currently, pretty high compression) -> also, there are *more* [zlib parameters](http://www.zlib.net/manual.html) with `png_set_compression_*` to tune! `window_bits`, `buffer_size` and `mem_level` seem [worth a look](http://www.zlib.net/manual.html#Advanced).\r\n- What is [PyPNG](https://pythonhosted.org/pypng/tr20091230.html) doing?\r\n- Is `libpng` itself the bottleneck?"},"comment":{"url":"https://api.github.com/repos/pngwriter/pngwriter/issues/comments/221807158","html_url":"https://github.com/pngwriter/pngwriter/issues/47#issuecomment-221807158","issue_url":"https://api.github.com/repos/pngwriter/pngwriter/issues/47","id":221807158,"user":{"login":"pkohut","id":150948,"avatar_url":"https://avatars.githubusercontent.com/u/150948?v=3","gravatar_id":"","url":"https://api.github.com/users/pkohut","html_url":"https://github.com/pkohut","followers_url":"https://api.github.com/users/pkohut/followers","following_url":"https://api.github.com/users/pkohut/following{/other_user}","gists_url":"https://api.github.com/users/pkohut/gists{/gist_id}","starred_url":"https://api.github.com/users/pkohut/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pkohut/subscriptions","organizations_url":"https://api.github.com/users/pkohut/orgs","repos_url":"https://api.github.com/users/pkohut/repos","events_url":"https://api.github.com/users/pkohut/events{/privacy}","received_events_url":"https://api.github.com/users/pkohut/received_events","type":"User","site_admin":false},"created_at":"2016-05-26T08:18:38Z","updated_at":"2016-05-26T08:18:38Z","body":"Ya, I spent a chuck of yesterday putting together a portable a Windows/OS X/Linux timer class.  Got ugly fast, especially since OS X does not have CLOCK_MONOTONIC available.  Stashed it after a while as the testing got to be a pain."}}
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