Bug 263550

Summary:	CANVAS : image shifts position in mouse-over mode when changing between Before and After
Product:	[Applications] digikam	Reporter:	schweigi
Component:	ImageEditor-Canvas	Assignee:	Digikam Developers <digikam-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	caulier.gilles, online
Priority:	NOR
Version:	2.0.0
Target Milestone:	---
Platform:	Compiled Sources
OS:	Linux
Latest Commit:		Version Fixed In:	4.6.0
Sentry Crash Report:

Description schweigi 2011-01-18 15:01:08 UTC

Version:           2.0.0 (using KDE 4.5.1) 
OS:                Linux

In the image editor when I use the mouse over mode to get a
view of "before" and "after" for (any) enhancement filter, the image itself get's a little bit shifted between the two views (except at a zoom setting of 100%).

Reproducible: Always

Steps to Reproduce:
Load any image into the image editor, choose a enhancement filter, set the zoom level to any level except 100%, activate the mouse-over mode and have a look how the image moves between the 'Before' and the 'After' sight...

Actual Results:  
image shifts position

Expected Results:  
image content shall not change its position

Comment 1 caulier.gilles 2011-01-18 15:25:06 UTC

The shift can be due to image processing result, which can move a little bit the image (refocus algorithm for example)...

Gilles Caulier

Comment 2 schweigi 2011-01-18 15:49:43 UTC

(In reply to comment #1)
> The shift can be due to image processing result, which can move a little bit
> the image (refocus algorithm for example)...

But the shift does not happen, when the zoom setting is set to 100%.
In addition the shift happens at zoom settings different to 100% (regardless if higher or lower than 100%) even e.g. I use a enhance-->sharpen filter with Sharpness set to 0 - so no processing should have been done...

Bernhard

Comment 3 Marcel Wiesweg 2011-01-18 16:50:46 UTC

Gilles, do these tools compute the preview only for the visible section? In some situations, there can be sub-pixel problems when scaling sections. We'd need to analyze how original and preview are scaled.

Comment 4 caulier.gilles 2014-08-29 13:42:32 UTC

schweigi,

This problem still valid using last digiKam 4.2.0 ?

Gilles Caulier

Comment 5 Jan Wolter 2014-12-10 18:36:40 UTC

I just tested this issue on 4.6.0 on different zoom levels from 10% to 1200%. There is absolutely no shift. Hence, from my point of view this bug can be closed.

Comment 6 caulier.gilles 2014-12-10 18:43:13 UTC

Thanks Jan for this report. This probably due to Maik Quallmann patches about zoom rules applied recently for next 4.6.0.

I close this file now. Don't hesistate to re-open if necessary.

Gilles Caulier