Bug 359087

Summary: Preview image scroll position should be smarter when changing between images with different resolutions
Product: [Applications] digikam Reporter: Michal Sylwester <msylwester>
Component: Preview-ImageAssignee: Digikam Developers <digikam-bugs-null>
Status: REPORTED ---    
Severity: wishlist CC: caulier.gilles, metzpinguin
Priority: NOR    
Version: 5.0.0   
Target Milestone: ---   
Platform: Ubuntu   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Michal Sylwester 2016-02-07 03:23:36 UTC
When watching images zoomed in it is currently possible to switch to different image and the are shown is preserved (this is convenient as a quick alternative to the light table). The problem occurs when the images have different resolutions. 
- With a same image in different resolutions different area will be shown
- While switching back and forth between images where one is lower resolution the position will be capped to the maximum of the smallest image. Happens when I cropped one image, and accidentally select it while working on another one.

Reproducible: Always

Steps to Reproduce:
Scenario 1:
1. Make sure there are 2 versions of image, high and low resolution 
2. Preview one of them
3. Switch to the other

Scenario 2:
1. Make sure one of the images in thummbar has significantly lower resolution 
2. Preview high-resolution image (preferabelly in lower right corner)
3. Switch to low-resolution image
4. Switch back to high resolution image


Actual Results:  
Scenario 1: Area further up and left from originally selected is visible
Scenario 2: Different area of the image is visible

Expected Results:  
Scenario 1: Same area as originally selected is visible
Scenario 2: Same area of both images is visible (here is the additional issue of whether and how zoom should be adjusted)

I think this may be a little tricky to make it work the way I would like, especially as it would most likely also require considerations about zoom level - should it change? Most of the time I don't care that much about actual zoom relative to "100%", more to the relative visible area of an image, so it would mean it should also change...
Comment 1 Michal Sylwester 2016-02-14 12:29:55 UTC
Recalled one more scenario where current implementation is inconvenient. I usually shoot photos in JPEG + RAW mode (so each shot results in 2 files). Beside the nuisance of having each photo fine it works fine, except when the zoom level is changed from 100%. As the RAWs are presented via the embedded JPEG, which has smaller resolution than the full one (in separate file), this also results in the annoying jumping of the zoomed in region.
Comment 2 Maik Qualmann 2016-02-17 21:59:55 UTC
Git commit 07f09f47cb876b4b964f4ca5fe9d8cf5f6fe97ea by Maik Qualmann.
Committed on 17/02/2016 at 21:58.
Pushed by mqualmann into branch 'master'.

fix wrong 100% visual view of a half size RAW preview

M  +3    -3    libs/widgets/graphicsview/imagezoomsettings.cpp

http://commits.kde.org/digikam/07f09f47cb876b4b964f4ca5fe9d8cf5f6fe97ea
Comment 3 Maik Qualmann 2016-02-17 22:02:13 UTC
This commit should solve the problem from Comment 1.

Maik
Comment 4 caulier.gilles 2020-08-02 13:26:29 UTC
digiKam 7.0.0 stable release is now published:

https://www.digikam.org/news/2020-07-19-7.0.0_release_announcement/

We need a fresh feedback on this file using this version.

Best Regards

Gilles Caulier