GNOME Bugzilla – Bug 730489
Scaled images are blurry (high quality zoom)
Last modified: 2020-11-14 09:12:49 UTC
The 3.2 series of gThumb (I'm using 3.2.7 in Ubuntu 14.04) makes scaled images very blurry, even if they are of a high resolution. Ironically, this occcurs when the "zoom quality" is set to "high". This did not happen in the 3.0 series. For comparison, here are links to the same image displayed in: gThumb 3. gThumb 3.0.2 (low zoom quality): https://i.imgur.com/OjUvxrY.jpg gThumb 3.0.2 (high zoom quality): https://i.imgur.com/OdgipnZ.jpg gThumb 3.2.7 (low zoom quality): https://i.imgur.com/dYGyQcd.jpg gThumb 3.2.7 (high zoom quality): https://i.imgur.com/4cBtfu7.jpg Note that there is very little difference between the high and low zoom quality in 3.0.2 (which makes sense since the image's resolution is 5184x3456). The low quality setting of both 3.0.2 and 3.2.7 seems identical. The high quality setting in 3.2.7 is very blurry however. This was pointed out here: https://bugzilla.gnome.org/show_bug.cgi?id=726087 That bug report discusses the slow image rendering issues that appeared starting in the 3.2 series (and continued with the 3.3 series). I do not know if these bugs are related.
I can confirm this still affects gThumb in Linux Mint 17.2 (still on the 14.04 LTS repositories. Gnome Image Viewer (3.10) does NOT suffer from this problem. The bug is fixed in gThumb 3.3.2 installed via PPA. Perhaps the change can be backported for LTS users?
I have version 3.4.3, elementary OS Loki and I have this bug.Large images (6000x4000px jpegs or camera raw files) are blurred (compared with other image viewers or Gimp, same file) when the zoom is set to high quality. At low quality zoom, the pictures are too pixelated, of course. Small images are fine. The blur is not present when the file is opened in gThumb through the file manager (I mean Nautilus or something else), but it gets blurred after browsing in gThumb and going back to that image. The blur is slight, but I'm a photographer and I notice it immediately.
bugzilla.gnome.org is being replaced by gitlab.gnome.org. We are closing all old bug reports and feature requests in GNOME Bugzilla which have not seen updates for a long time. If you still use gthumb and if you still see this bug / want this feature in a recent and currently supported version, then please feel free to report it at https://gitlab.gnome.org/GNOME/gthumb/-/issues/ by following the guidelines at https://wiki.gnome.org/Community/GettingInTouch/BugReportingGuidelines Thank you for creating this report and we are sorry it could not be implemented so far (volunteer workforce and time is limited).