kdeprint quality problems

[Michael Goffioul]

> I'm running KDE 3.1.2 under FreeBSD-4.8 and I'm having a problem with
> kdeprint.
> When I print a file (with CUPS) using kdeprint, the output quality is
> very bad (although I chose photo printing/1200 dpi).
> If I use the command line or another CUPS frontend like gtklp, the
> output is gorgious.
> My guess is that kdeprint must do some prossessing of my pictures before
> sending them to the spooler: I can see on the preview that the quality
> is very bad (like 300 dpi).
> Is there a way to avoid this ? I mean, can I just send my files
> untouched to the CUPS spooler (that will then take of the conversion
> and all using his own filter: foomatic-rip and hpijs GS driver).

Basically, it depends on how you print the image. When using a KDE
application (let's say kview or kuickshow), the image is first
converted to PS before being sent to the CUPS spooler. During this
conversion, a specific resolution value is used, which is typically
the screen resolution (75 to 100 dpi). When the CUPS spooler then
process the PS file, it doesn't change much to set the printer to
a high resolution, because the quality is limited by the resolution
that were used during PS generation.

When using the "kprinter" front-end, or other program like xpp or
gtklp, the image file is sent directly to the printer without prior
conversion to PS, so the CUPS spooler takes care of the complete
rasterization, which can be done at full resolution, hence a better
print quality.

When using a KDE application, it's the responsability of the app to
define the PS generation resolution, so this part is out of the
scope of KDEPrint. Note however that recent changes in the code
will allow KDEPrint to feed back the actual selected printer
resolution to the application, such that the app would be able
to generate PS at the resolution that the printer will use. But
again, it will be up to the application to choose that particular
resolution value. In the ideal case, if you selected Photo quality
in the printer properties dialog (for example 1200dpi), the application
will use 1200dpi resolution value to generate the PS data.

Michael.

-- 
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Michael Goffioul		IMEC-DESICS-MIRA
e-mail: goffioul at imec.be	(Mixed-Signal and RF Applications)
Tel:    +32/16/28-8510		Kapeldreef, 75
Fax:    +32/16/28-1515		3001 HEVERLEE, BELGIUM
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