Bug 46817

In addition to the poor quality of the text rendering, LO impress changes the spaces between the characters if you click in a text object or switch to another slide in presentation mode. 
I classified this bug (or feature request if not implemented) as important because this degrades the overall acceptance of LO (cf. e.g the good anti-aliasing in MS Office).

Text rendering seems to have improved in LO V3.5.4.2 (tested with Windows 7 Prof. 64bit) but is still not perfect. There are no more changes of character spaces when moving from one slide to another in LO Impress presentations. But there are still "anomalies" in text rendering when using slide show effects (font rendering is changed somewhat from bold to normal just after finishing of the slide show effect).

Created attachment 79419 [details]
screenshot of Win7 in a VM with AA (and cleartype) working nicely ...

This bug appears too unclear to me to be a MAB; for me AA works nicely on Windows (and ~always has). Can you confirm that this still fails to work with 3.6 - and can you give much more iformation:

What version of Windows ? what fonts are you using ? which component are you using ? can you attach a document that is affected ?

Thanks ! :-)

Created attachment 79546 [details]
screenshot comparison of AA

comparison of AA on and off and PDF output(how I think it's supposed to look).
Done on Windows7 as fullscreen presentation. AA/noAA means antialiasing switched on/off in Impress settings. noDPI means it is run without DPI scaling otherwise it is run on with 133% DPI scaling and compatibility flag "Disable display scaling on high DPI" set.
AA1 - extra horrible result on chosen fonts.
AA2 - more standard Arial fonts.

I did some coparison on LibreOffice 4. I had this issue as long as I can remeber, but I will try on 3 version if requested.
On closer look I noticed there is some attempt at AA(it is not just black and white pixel values), but result for AA switched on and off is exactly the same and exported PDF gives much superior visual quality(I use Foxit to display).

When I think about it, it is actually not AA problem but the same as bug 36426.

Hello Stefan, *,
does your comment 7 mean, that this one can be closed as a duplicate?
If so, I will close it (or better: If you could close it as a duplicate".
Sorry for the inconvenience
Thomas.

Hello Thomas,
sorry for that confusion, it is probably not duplicate. It does fit the description of the OP in that bug, but it's too vague to be sure and screenshots there(by another poster) are completely different from my issue.

to Stefan: It would be nice if you could confirm, that you have the same issue as I based on the attachement from me, if you are still with us. Otherwise I should probably make a new bug report for it.

!
Also I found out that switching ClearType off fixes my problem with font rendering quality(of user content, but UI fonts gets ugly). (So it is only Windows related).

And there remains the bug or intent that unchecking the "Use Anti-Aliasing" option does not turn off font antialiasing.

There are several problems with font rendering with LO even with the latest version 4.0.4.2 (tested on WIN 7 Pro 64bit):
- antialiasing is worse than with MS Powerpoint (feature optimization required)
- turning on/off antialiasing in LO makes no difference (bug)
- with LO impress there is a visible antialising/optimization process on changing slides which looks bad (bug/optimization required)
- font spacing is not even which looks also bad (seems to be the problem described in bug 36426)

I've attached a demo presentation where you can see the font rendering problems on turning slides. I

Created attachment 82119 [details]
LO presentation which shows font rendering probems

The font rendering problem occurs mainly with LO impress (on turning slides).
With LO Writer no font spacing problem occurs but the bug with turning on/off antialising is the same: it has no effect on the fonts except on lines (underscore).

Created attachment 82120 [details]
Uneven character spacing

Spaces between each character varies.

Created attachment 82121 [details]
Even Character spacing with MS Powerpoint

For comparision: Even Character spacing with MS Powerpoint 2010. No character touches another as with LO impress.

The font rendering problem only occurs on Windows. On e.g. Ubuntu everything is fine!