Bug 346077

Summary:	Loss of quality in view when zoom is locked
Product:	[Applications] gwenview	Reporter:	Greg Lepore <greg>
Component:	general	Assignee:	Gwenview Bugs <gwenview-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	myriam, nate
Priority:	NOR
Version First Reported In:	5.0.0
Target Milestone:	---
Platform:	Kubuntu
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Low quality image with zoom locked Actual quality on initial load or on change zoom

Description Greg Lepore 2015-04-11 15:37:58 UTC

Moving through images using the next/previous buttons delivers constantly high quality views of images. However, changing the zoom level with keep same zoom and position set produces lower quality views. See attached image1.jpg for a detail of an image with the lower quality, and image2.jpg for the view after zooming in and back out.

Reproducible: Always

Steps to Reproduce:
1. Open image, observe high quality rendering
2. Change zoom mode in settings to keep same zoom and position
3. Open image, change the zoom level
4. Move to another image, all subsequent images at the same zoom are lower quality renderings
5. Change zoom on an image and the quality returns

Comment 1 Greg Lepore 2015-04-11 15:38:31 UTC

Created attachment 91984 [details]
Low quality image with zoom locked

Comment 2 Greg Lepore 2015-04-11 15:38:53 UTC

Created attachment 91985 [details]
Actual quality on initial load or on change zoom

Comment 3 Greg Lepore 2015-04-11 15:44:49 UTC

Note that this bug does not appear to occur when the locked zoom level is 100% or "Fit". It does appear to occur on other zoom levels (mine was 72%).

Comment 4 Greg Lepore 2016-01-20 12:32:24 UTC

This bug is still occurring with:

Version 15.08.3
KDE Frameworks 5.18.0
Qt 5.5.1 (built against 5.5.1)
The xcb windowing system

It appears that the default quality when moving from one image to another is low, and zooming in or out on the subsequent image produces a higher quality rendering.

In other words, when using the next button to move to a second image, the initial quality of that image is low. Zooming in and then back out to the same resolution as before produces a much higher quality image. So unfortunately, every time I move to another image, I have to zoom in and then back out (or the other way around) to get a high quality image.

Alternately, opening the image directly produces the higher quality image, only moving from image to image with the next/previous buttons produces a lower quality rendering.

Comment 5 Nate Graham 2017-11-10 20:15:30 UTC

I don't believe I'm able to reproduce this in Gwenview from 17.8.x. Can you?

Comment 6 Greg Lepore 2017-11-10 20:21:43 UTC

I can no longer reproduce this bug, looks like it's been solved. I'm on 17.08.2.

Comment 7 Nate Graham 2017-11-10 20:22:23 UTC

Fantastic!