OpenOffice.org uses DPI setting to determine page scaling and Gnome hardcodes DPI

[christoph]

Binary package hint: openoffice.org

When I, for instance, set the page size to a4 and the zoom level to 100% I expect my computer screen to show the page
in real size. But if I grab a real a4 sheet of paper from my desk and hold it against my computer screen,
I see that openoffice shows the page too large.

by the way, if I export my file as pdf,
evince shows the page correctly.

ProblemType: Bug
Architecture: amd64
Date: Mon Oct 6 19:28:44 2008
DistroRelease: Ubuntu 8.04
NonfreeKernelModules: nvidia
Package: openoffice.org-core 1:2.4.1-1ubuntu2
PackageArchitecture: amd64
ProcEnviron:
 PATH=/usr/lib/openoffice/program:/home/username/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: openoffice.org
Uname: Linux 2.6.24-19-generic x86_64

[Chris Cheney (ccheney)]

It's within a quarter of a cm of being the right size on my screen for Letter size (I'm in the US). Do you have your X dpi setting set correctly for your monitor?

Chris

[christoph (christophs)]

I'm not sure about that X dpi setting. How can I change it or read its value?
But if I look at an a4 pdf page in evince, it has the correct size (if set to 100%).
So I guess my dpi setting is correct.

[Chris Cheney (ccheney)]

Like this:

$ xdpyinfo | grep -A3 ^screen

screen #0:
  dimensions: 1280x800 pixels (331x207 millimeters)
  resolution: 98x98 dots per inch
  depths (7): 24, 1, 4, 8, 15, 16, 32

[Chris Cheney (ccheney)]

How much off is it for your screen? On mine it is off a little but by a very small amount.

[christoph (christophs)]

The output is
$ xdpyinfo |grep -A3 ^screen
screen #0:
  dimensions: 1680x1050 pixels (474x303 millimeters)
  resolution: 90x88 dots per inch
  depths (7): 24, 1, 4, 8, 15, 16, 32

The acer website
http://www.acer.de/public/page9.do?sp=page4&dau34.oid=29541&UserCtxParam=0&GroupCtxParam=0&dctx1=9&CountryISOCtxParam=DE&LanguageISOCtxParam=de&ctx3=62&ctx4=Deutschland&crc=1769969506
about my monitor tells me it is 473x296 mm size.

In openoffice though, the displayed a4 page is about 1.3 cm too wide.
And that is clearly visible.

[Chris Cheney (ccheney)]

I think I may have found the problem and well fixed the problem on my system at the same time.

If you adjust the DPI setting in "System->Preferences->Appearance->Fonts->Details" and set it to ~ 89 DPI which is an average between the two numbers your computer gives you for your screen it will probably look correct (or very close). It appears you have to logout for the change to fully take effect.

Chris

[christoph (christophs)]

In fact, this really worked.
But I had to set the value to 90 to make it look correct.
The page size is also correct now in evince

As a side effect, all other fonts are also smaller now.

Can you tell me how you figured out these ~ 89 DPI?

Thanks, Christoph

[Chris Cheney (ccheney)]

Yes, it was your monitor that told me. :)

  resolution: 90x88 dots per inch

That says what it should be, but Gnome is hardcoded to 96 dpi.

Reassigning to Gnome, though I doubt they will fix this due to other reasons. If I remember correctly since Gnome isn't fully DPI aware adjusting it too much will cause problems.

Chris

[hackel (hackel)]

I marked this as a duplicate of #157398 because that is the source of the problem. OpenOffice.org is doing the right thing, so this isn't even really a bug. But the problem the user is experiencing will be resolved when #157398 is fixed.

[Alex Salt (holy.cheater)]

This is a bug, in fact.
I use 72 dots per inch resolution. So when I open a word/excel document in OpenOffice it looks smaller than it should be than it should be. Everything becomes unreadable at 100% zoom. Excel in Windows renders the document at 96 dots per inch. Ubuntu default resolution is 96 dots per inch. It means the document will look different on various computers because of user settings.
So, for example someone set row height to 20 pixels in Excel using Windows. I open the document, it calculates this 20 pixels to inches at 96 dpi, then it renders it from inches to pixels at 72 dpi (which are taken from my settings), so row height on my screen will be 15 pixels.

echo Xft.dpi: 72 | xrdb -merge
Open some document in OO. Close OO.
echo Xft.dpi: 96 | xrdb -merge
Open again, see the difference