| Date: | Thu, 25 May 2000 16:42:44 +1000 |
| Reply-To: | Tim CHURCHES <TCHUR@DOH.HEALTH.NSW.GOV.AU> |
| Sender: | "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU> |
| From: | Tim CHURCHES <TCHUR@DOH.HEALTH.NSW.GOV.AU> |
| Subject: | Solved: variable quality of TrueType fonts in GIFs under V8 |
| Content-Type: | text/plain; charset=US-ASCII |
Previously I wrote:
>> We are currently converting a large Web publishing project from SAS V6.12 (under Win NT) to
>> V8.00 (production release), mainly because text in GIF graphics files produced by V8.00 when
>> a TrueType font is specified looks so much better than the funny-looking and often barely legible
>> text in GIFs produced by V6.12.
>>
>> But (there's always a but), we have found that whenever the font size increases beyond a certain
>> point, the quality of the text in the V8-produced GIFs suddenly degrades and becomes jagged and
>> looks even worse than the text in V6.12 GIFs. This seems to be related to the absolute size of the text.
>
> OK, to summarise:
>
> - the problem only affects SAS Version 8 using the GIF driver with TrueType fonts.
>
> - the problem only occurs with proportionally-spaced TrueType fonts. Monospaced fonts ae unaffected.
>
> - the problem only manifests when the absolute font size exceeds a certain point. This may be caused by
> specifying a bigger font size relative to the graphic or by specifying a bigger graphic (e.g. 800 by 600 pixels
> instead of 470 by 630 pixels) or both.
>
> - the problem only manifests when non-white backgrounds are used.
>
> - the problem is caused by SAS V8 invoking some sort of anti-aliasing routine to smooth the contours of
> fonts once they exceed a certain size. That's good. The problem is that SAS does the anti-aliasing by
> inserting white pixels here and there to smooth jagged edges. That's bad, unless background colour is white,
> in which case white is the correct colour for these anti-aliasing pixels. If your background colour is not white or
> close to it, the effect is to create a sort of jagged halo around the letters which seriously detracts from their
> beauty and in some cases renders them almost illegible.
The mystery is now solved (by moi).
Under Windows NT V4.0 (and maybe Windows 9x, not sure):
Go to Start | Settings | Control Panel | Display
Click on the Plus! tab
Set "Smooth edges of screen fonts" to on.
Click on "Apply" or "OK"
Now large TrueType fonts in GIF files produced by SAS V8 will look horrible.
Set "Smooth edges of screen fonts" to off.
Click on "Apply" or "OK"
Now large TrueType fonts in GIF files produced by SAS V8 will look OK.
Thank goodness the US DOJ has not (yet) removed Microsoft's freedom to provide us all with this sort of innovation.
At least now I don't have to hand edit the font sizes in 387 individual SAS programmes...thank you Bill, I'm grateful.
Tim Churches
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