KDM background image not displayed correctly on wide screen display

[Michael Ummels]

On a 1024x600 display, when KDM (KDE 4.3 version) is started with the default Air theme, the background image only fills the center of the screen (maybe 800 pixels) wide. On the edges, random noise is displayed. I guess, this is due to an incorrect scaling behaviour of this theme.

Description: Ubuntu intrepid (development branch)
Release: 9.04

[Luis Silva (lacsilva)]

The following patch soled the problem for me on an asus eeepc.

[Harald Sitter (apachelogger)]

Fixed in KDE 4.1.1 (to be released sometime next week).

[Jonathan Thomas (echidnaman)]

Fix released in kdebase-workspace 4.1.1-0ubuntu3 in Intrepid.

[Michael Ummels (urmel291)]

This problem persists in kdebase-workspace 4.1.1-0ubuntu9!

[George Moody (gmlnx+)]

The problem persists in kdebase-workspace 4.1.2-0ubuntu2

[Luis Silva (lacsilva)]

This problem still persists therefore I repost my patch for everyone to use. It's just a little bit rearranged.

[George Moody (gmlnx+)]

The patch worked for me, on an Advent 4211 (MSI Wind rebadged)

[Michael Ummels (urmel291)]

Here is a patch for the kdebase-workspace source package. The scaling of the background should be set to 100% wrt. both width and height in order to have the same background as for the splash screen.

[Michael Ummels (urmel291)]

Okay, when setting width and height to 100%, the background picture looks distorted on narrow displays (like 4:3 screens). Is there no way to scale the image's width and height proportionally until the entire screen is filled (cutting top and bottom on wide displays and cutting left and right on narrow displays)? The problem with the original patch is that it works fine on widescreen displays, but if you have a 4:3 screen, the background image does not extend to the top and bottom of the screen.

[Swâmi Petaramesh (swami-petaramesh)]

I confirm the exact same problem as in the bug description in released Kubuntu 8.10 Intrepid, on a 1024x600 display (Acer Aspire One).

[Luis Silva (lacsilva)]

The problem persists on jaunty. Is it so difficult to correct this bug or simply apply the workaround patches?

[Harald Sitter (apachelogger)]

Yes

[Jörg Wendel (linux-jwendel)]

The problem persists on intrepid with kde 4.2, width="100%" wokes fine

[Giovanni Masucci (gio-grifis)]

Settings both width and height fixes the problem from me both on 16/9 and 4/3
<pos anchor="c" x="50%" y="50%" width="100%" height="100%"/>
Of course in 4/3 the wallpaper looks stretched but:
- most mordern note/netbooks are widescreen
- the wallpaper is an abstract one so I think this doesn't look so bad
- The garbage on the sides of the screen that we have now is way worse.
- As a side note this solves another ugly issue: when going from kdm to the splash screen with the default configuration the wallpaper is stretched and destretched a few times. This doesn't happen with the fix above.
So, is it possible to make this change for jaunty and possibly push it upstream?

[Michael Ummels (urmel291)]

The fix works perfect for me. Indeed, there is now no difference between the background in KDM and the background for the splash screen.

[grey (canisrogeris)]

Shouldn't the image be formatted to the smallest screen height/width ratio you expect, then stretched to 100% of the screen width and the height scaled the same and cropped?

To cover 4:3, 16:10 and 16:9 screens, you'd format the image 4:3 and set width = "100%" height="scale".

That would not work for screens taller than they are wide (rotated monitors for instance), but formatting the image to 9:16, putting the original image in the middle and filling the open areas at the top and bottom would handle all screens from 9:16 to 16:9. As far as I can tell, this is how the scale and crop wallpaper position works.

You would have to reformat the background used with the splash screen to match. RIght now it seems to be scaling both dimensions to 100%, which would cause a shift in aspect ratio on anything but a 16:10 screen (I think?)

[Launchpad Janitor (janitor)]

This bug was fixed in the package kdebase-workspace - 4:4.2.1a-0ubuntu6

---------------
kdebase-workspace (4:4.2.1a-0ubuntu6) jaunty; urgency=low

  * Add kubuntu_69_fix_plasma_startup_crash.diff to fix KDE bug 186324, can
    be unapplied in KDE 4.2.2 (LP: #338205)
  * Add kubuntu_70_fix_widescreen_kdm_theme.diff to fix KDE bug 169772, can
    be unapplied in KDE 4.3.x (LP: #259181)

 -- Jonathan Thomas <email address hidden> Sat, 14 Mar 2009 14:23:26 -0400

[Luis Silva (lacsilva)]

It seems to work for me without any patch now. Thanks!

[Jonathan Thomas (echidnaman)]

Bah, it's back in KDE 4.3.0. Oh well, at least it has the same fix. Shouldn't be hard at all to get into the next packaging upload.

[Jeremy LaCroix (jlacroix82-deactivatedaccount)]

I have been applying all updates as they come in, and I can confirm that this problem is NOT fixed in Kubuntu Jaunty 64-bit.

[Jonathan Thomas (echidnaman)]

A real fix (aside from the temporary stretch business) has been made in trunk. It'll be backported to a future 4.3.x release after a bit of testing.

[Jeremy LaCroix (jlacroix82-deactivatedaccount)]

With KDE 4.3.1, this problem is still not solved in Jaunty.

[Yannis Tsop (ogiannhs)]

With latest KDE in karmic I have the same problem with only one computer that has a hig resolution (1920x1080), all others (up to 1680x1050) work ok.

[flowerdealer (pixelcowboy79)]

I also have this still issue with alpha 5.

On Sat, Sep 5, 2009 at 8:55 AM, Yannis T<email address hidden> wrote:
> With latest KDE in karmic I have the same problem with only one computer
> that has a hig resolution (1920x1080), all others (up to 1680x1050) work
> ok.
>
> --
> KDM background image not displayed correctly on wide screen display
> https://bugs.launchpad.net/bugs/259181
> You received this bug notification because you are a direct subscriber
> of a duplicate bug.
>
> Status in KDE Base Components: Fix Released
> Status in “kdebase-workspace” package in Ubuntu: Fix Committed
>
> Bug description:
> On a 1024x600 display, when KDM (KDE 4.3 version) is started with the default Air theme, the background image only fills the center of the screen (maybe 800 pixels) wide. On the edges, random noise is displayed. I guess, this is due to an incorrect scaling behaviour of this theme.
>
> Description:    Ubuntu intrepid (development branch)
> Release:        9.04
>
>

[Jonathan Thomas (echidnaman)]

Fixed in KDE 4.3.2.