Last modified: 2014-03-04 18:35:12 UTC

Wikimedia Bugzilla is closed!

Wikimedia migrated from Bugzilla to Phabricator. Bug reports are handled in Wikimedia Phabricator.
This static website is read-only and for historical purposes. It is not possible to log in and except for displaying bug reports and their history, links might be broken. See T20936, the corresponding Phabricator task for complete and up-to-date bug report information.
Bug 18936 - Hairline / seam in SVG rendering
Hairline / seam in SVG rendering
Status: NEW
Product: Wikimedia
Classification: Unclassified
SVG rendering (Other open bugs)
All All
: Normal normal with 1 vote (vote)
: ---
Assigned To: Nobody - You can work on this!
Depends on:
Blocks: svg
  Show dependency treegraph
Reported: 2009-05-26 15:54 UTC by Tom Edwards
Modified: 2014-03-04 18:35 UTC (History)
5 users (show)

See Also:
Web browser: ---
Mobile Platform: ---
Assignee Huggle Beta Tester: ---

rendering of the problem (36.30 KB, image/png)
2011-12-04 21:14 UTC, Derk-Jan Hartman

Description Tom Edwards 2009-05-26 15:54:47 UTC
Three SVG files identical in every way but their colour have been rendered differently:

The issue is along the centre of the image from top to bottom. The black image has a barely-noticeable seam, and the red image has no seam at all, yet the green image has a very noticeable seam all the way through. It may be helpful to zoom in on the rasters to see what I'm talking about.

The left half of the image is mirrored to create the right half, which explains but doesn't excuse the seam - the two halves actually *overlap* each other!

Given that the seam comes and goes depending on the size of the raster, I'd tentatively put this down to rounding errors...
Comment 1 Aryeh Gregor (not reading bugmail, please e-mail directly) 2009-05-26 16:01:54 UTC
Not a MediaWiki issue.  MediaWiki doesn't do SVG rasterization, it just passes off to third-party tools.  Refiling as Wikimedia.  Checking whether it works in the latest version of whatever SVG renderer we use (librsvg, was it?) would probably be helpful.
Comment 2 Tom Edwards 2009-05-26 17:11:37 UTC
I've just given up trying to compile librsvg for Windows. GNU is as impenetrable as ever...

Someone else will have to test the latest build.
Comment 3 Tom Edwards 2009-05-27 10:04:24 UTC
I changed the red image to a darker shade and it's now developed a seam as well. Check the file history for the version unaffected by this bug:
Comment 4 Brion Vibber 2009-08-03 16:53:53 UTC
Assigning SVG bugs to Ariel -- need a cleanup pass to see what's fixed up by a librsvg upgrade, what can be resolved with fixes to our font configuration, what can be fixed on our end, and what still needs to be pushed upstream.
Comment 5 Ariel T. Glenn 2011-09-18 09:31:56 UTC
giving SVG bugs back to the pool.
Comment 6 Derk-Jan Hartman 2011-12-04 21:14:47 UTC
Created attachment 9611 [details]
rendering of the problem

The issue still seems to exist, after the recent librsvg update.
Comment 7 matanya 2012-08-05 21:05:06 UTC
Seems to be solved with recent rsvg update, can One confirm?
Comment 8 Derk-Jan Hartman 2012-10-26 09:33:00 UTC
I temp undeleted this (green) file and it still seems to be problematic.
Comment 9 Derk-Jan Hartman 2012-10-26 14:13:44 UTC
See also:
Comment 10 PRO 2012-11-03 16:48:53 UTC
I propose a other name for this ''hairline'' bug. "Colour-dependent" is completely unrelated. 

See also:
[[File:SVG 3 paths.svg]]

Some browsers have the same bug (on zooming).

Note You need to log in before you can comment on or make changes to this bug.