Artifacts in rendering of Gaussian blur filter (horizontal stripes)

Bug #1656383 reported by Patrick Storz
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
Inkscape
Undecided
Unassigned

Bug Description

When zooming far into a blurred region (or setting a large blur radius) artifacts appear in the rendering of the Gaussian blur filter (horizontal stripes with changing color, see screenshot).

The screenshot was made with Inkscape 0.92.0 (64-bit) on Windows 10 x64 but current trunk (r15415) is affected, too.

The issue is dependent on the rendering quality set in preferences: The lower the quality setting the earlier (i.e. for lower zoom, smaller blur radius) the artifacts become visible.
Only for the highest quality setting I could not see any artifacts (but rendering gets so slow on my machine that i can't zoom in very far, so I can't completely rule out that it's affected, too).

Revision history for this message
Patrick Storz (ede123) wrote :
Revision history for this message
Patrick Storz (ede123) wrote :

Some helpful comments from su_v via IRC:
based on tests with archived builds: not seen with 14904, seen with 14914
https://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/changes/14914
could have been exposed with the fix for the broken quality settings in
https://bazaar.launchpad.net/~inkscape.dev/inkscape/trunk/revision/14913
(i.e. the issue could have been there before that (?))
I tested with default (new) prefs for each run.
they seem to go back to early cairo-rendering merges
I do see them with 10578 (before the merge of the renderer caching branch)
I do not see them with 10579 (the merge of the caching branch)
but that's also the commit which disabled the quality prefs (based on my earlier tests)

Revision history for this message
Patrick Storz (ede123) wrote :

And another comment by su_v:
Bug #1651915 is not related - the lines described there also reproduce with 14904

Revision history for this message
su_v (suv-lp) wrote :

Confirming based on my tests as quoted from irc.

The mentioned tests had been done with archived trunk builds on OS X 10.7.5, with default (new) preferences for each run.

tags: added: filters-svg regression renderer-cairo
Changed in inkscape:
status: New → Confirmed
Revision history for this message
Tavmjong Bah (tavmjong-free) wrote :

Definitely related to tiling. With trunk one can now visualize the tiles by uncommenting a line in src/desktop.cpp (canvas_debug) to see the tiles. Tile edges align with the discontinuities.

To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers