Bug 411719

Summary: Gaussian blur produces artefacts or boxed output
Product: [Applications] krita Reporter: Raghavendra kamath <raghu>
Component: FiltersAssignee: Dmitry Kazakov <dimula73>
Status: RESOLVED FIXED    
Severity: normal CC: dimula73
Priority: NOR Keywords: regression
Version: git master (please specify the git hash!)   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: https://invent.kde.org/kde/krita/commit/edab84fb29e75bc4acffc5cb2af7ef3a38f5da1a Version Fixed In:
Sentry Crash Report:
Attachments: image shwoing the artefact

Description Raghavendra kamath 2019-09-08 15:40:17 UTC 
Created attachment 122542 [details]
image shwoing the artefact

SUMMARY
While testing the master branch - 4.3.0-prealpha (git 5c326ec) I encountered a bug in Gaussian blur filter. the output of the filter is chipped like a mismatched tile. I have attached a example image to better describe it.

The artefact depends on the place of the object and mostly is reproducible easily with a square shaped object.

STEPS TO REPRODUCE
1. Open Krita and a new a4 document, draw a rectangle selection in the middle of the document
2. Run Gaussian blur filter with radius of 500 or more, the more is the radius more clear the artefact will be


A video of the bug can be viewed here -> https://box.raghukamath.com/cloud/index.php/s/5MkDqKRxD52fzmf

Operating System: Arch Linux 
KDE Plasma Version: 5.16.5
KDE Frameworks Version: 5.61.0
Qt Version: 5.13.0
Kernel Version: 5.2.11-arch1-1-ARCH
OS Type: 64-bit
Processors: 8 × Intel® Core™ i7-4790K CPU @ 4.00GHz
Memory: 15.6 GiB of RAM
Comment 1 Dmitry Kazakov 2019-09-09 12:08:22 UTC 
I can confirm. And that is surely a regression, since I fixed that a few times already :)
Comment 2 Dmitry Kazakov 2019-09-09 13:48:29 UTC 
Git commit 14efe87feb5862eef30f0aab94619650fadf95cb by Dmitry Kazakov.
Committed on 09/09/2019 at 13:48.
Pushed by dkazakov into branch 'master'.

Fix artifacts in Gaussian Blur on transparent layer

Our border-repear strategy should work not on the exact
bounds of the device, but on the bounds of the image.

M  +1    -1    libs/image/kis_convolution_painter.cc

https://invent.kde.org/kde/krita/commit/14efe87feb5862eef30f0aab94619650fadf95cb
Comment 3 Dmitry Kazakov 2019-09-13 09:59:55 UTC 
Git commit edab84fb29e75bc4acffc5cb2af7ef3a38f5da1a by Dmitry Kazakov.
Committed on 13/09/2019 at 09:00.
Pushed by dkazakov into branch 'krita/4.2'.

Fix artifacts in Gaussian Blur on transparent layer

Our border-repear strategy should work not on the exact
bounds of the device, but on the bounds of the image.

M  +1    -1    libs/image/kis_convolution_painter.cc

https://invent.kde.org/kde/krita/commit/edab84fb29e75bc4acffc5cb2af7ef3a38f5da1a