[kde-linux] Gwenview Questions

Duncan 1i5t5.duncan at cox.net
Tue Nov 4 05:56:44 UTC 2014

Vojtěch Zeisek posted on Mon, 03 Nov 2014 20:59:11 +0100 as excerpted:

> I use this function in digiKam (KDE 4.14, openSUSE 13.1) - it has been
> there for many versions. I think it requires kipi plugins. Do You have
> that package installed?
> Vojtěch
> Dne Po 3. listopadu 2014 13:18:10, Robert Rea napsal(a):
>> KDE 4.10.5 "release 1"
>> opensuse 12.3
>> In the previous version I used with opensuse 11.0 there was a utility
>> to find duplicates and eliminate them. I don't see this now. Is it
>> supplied somewhere else?
>> When I view a pic in full screen, it doesn't fit itself to the screen
>> as the older version did. Is there some way to change this?

Yes, that would be kipi-plugins.  Both digikam and gwenview can use them.

(Meanwhile, please don't top-post.  It screws up the quote logic for 
further replies.)

As for the full-screen thing, gwenview's default changed.  It now seems 
to be shrink the displayed image to size of the window if the image is 
larger than the window, but view at 100% if it's smaller than the 
window.  So the whole image should be visible either way, but gwenview no 
longer zooms in by default if the image is smaller than the window.

That disturbed me too.  I actually found and installed an alternative 
viewer called gimv (GImageView, gtk-based) as a result.

But after a couple versions, gwenview got an option in settings, on the 
imageview tab, to "enlarge smaller images".  (For some reason that 
setting is grouped as if it's supposed to be part of the mousewheel 
settings.  I'm not sure if that's deliberate or not, but even knowing the 
option is there, I just about missed it when I just now opened gwenview 
settings to verify, because I expected it to be a main option, not under 
mousewheel.)  That returns to the behavior you (and I) preferred.

However, current kde is 4.14.  With minor feature-release bumps every six 
months, 4.10 is two years outdated now!  I don't remember when the 
default zoom behavior change occurred and when the checkbox was 
subsequently introduced to return it to how it was, but it's quite 
possible you're on one of the versions between when the new behavior was 
introduced and the introduction of the option to let people wanting the 
old behavior get it.  If so, I'd suggest upgrading to something a bit 
more current...

However, I actually found a better solution for me, and thus have that 
gwenview option set to keep small images to 100%.

The solution that works better for me is the zoom desktop effect, 
available (if you're running kwin as your window manager, which you 
likely are if you are running kde and haven't specifically chosen 
something else) in kde system settings, workspace appearance and 
behavior, desktop effects, on the all effects tab.  

Zoom should be the last effect under the accessibility group.  Once 
you've enabled it, you can click the configure button to see and/or 
modify the keyboard shortcuts that control it, and to set the size of the 
zoom step and mouse behavior while zoomed.

Here, I set meta-ctrl-arrows (meta=win[1]) as my zoom keys.  win-ctrl-
down zooms out, win-ctrl-up zooms in, and win-ctrl-left restores actual-
size.  These are intuitive and MUCH easier for me to remember than the 
default accelerator keys, and with the win/meta key as part of the 
combination, they don't conflict with individual app accelerator keys. 

I have zoom-factor set to 1.01, which while a tiny increment on its own, 
yields a nice smooth zoom effect when the shortcut keys are held down, 
triggering repeat-zoom in or out.  Mouse pointer I have set to keep as 
the other options didn't work well for me, and mouse tracking is set to 
proportional.  Note that some of the mouse tracking options were buggy in 
older kde4 versions, but as of 4.14.2, they all seem to work reasonably 
well, here.

What's nice about the zoom effect is that kwin uses OpenGL based hardware 
acceleration for effects if you have it set to do so (desktop effects, 
advanced tab, compositing type), and on reasonably modern hardware, it's 
quite fast.  With Radeon Turks (hd6670 IIRC) graphics and the native 
freedomware kernel and mesa drivers, I get very smooth zoomed 
functionality with no hickups even tho I'm running a full triple Full-HD 
monitor setup (stacked for 1920x3240 total desktop display area).  I 
remember a time when things didn't work so well on hardware compatible 
with freedomware drivers...

But what's particularly nice about using the zoom effect with gwenview 
set to display images at 100%, instead of using gwenview's zoom, is that 
the opengl zooming is less pixelated.  At over 4X zoom the effect can get 
noticeably blurry, but I still find that less annoying than the blocky 
pixelation at similar gwenview zoom, and sometimes I'll combine them, say 
2X gwenview zoom, desktop zoom from there, reducing both pixelation and 
blurriness from that of just the one zoom type alone.

I've found kwin's general desktop zoom similarly useful for other things, 
say zooming in on a low resolution video playing at 100% size instead of 
zooming the video window to several hundred percent, or sitting back and 
zooming in on konsole or firefox windows while keeping several windows on 
the desktop so I can mouse the viewport between them, instead of 
maximizing individual windows and zooming the content using the 

Since I use the kwin desktop zoom effect so much it's instinctive these 
days, and because it's both faster and less pixelated than individual app 
zoom (including gwenview), even tho gwenview has an option to enlarge 
small images by default again now like it used to without the option at 
all, I keep that option turned off now, so small images stay at 100%, and 
use kwin's generic desktop zoom effect on them instead, same as I use it 
for all my other zooming needs. =:^)

[1] Meta key:  FWIW, what kde refers to as meta is also variously known 
as the super or hyper or windows key, and I set various combinations of 
windows key shortcuts to control all my windows functionality, from meta-
end aka win-end replacing alt-F4 to close a window, to win-c for the cube 
desktop-switcher effect, to win-ctrl-arrow for the zoom effects, to...

Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman

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