[Foomatic] Bugus print with Lexmark E210/300dpi

Marcelo Ricardo Leitner mrl at conectiva.com.br
Mon Mar 1 10:53:56 PST 2004


On Seg Mar 01, 2004 at 13:25:00 -0500, Grant Taylor wrote:
> Marcelo Ricardo Leitner <mrl at conectiva.com.br> writes:
> 
> > I'm using this printer with cups+foomatic and it is configurated directly
> > through foomatic-configure. What happens is that I can't print with 300dpi
> > resolution, but I can do it via Windows. The other resolutions seems to be
> > ok.
> > 
> > When printing at 300dpi I got a "quaked" print. I have one test page scanned
> > over here http://bugzilla.conectiva.com.br/attachment.cgi?id=882&action=view
> > and the page that should have been printed
> > http://bugzilla.conectiva.com.br/attachment.cgi?id=906&action=view
> 
> > Any ideas of what could be happening?
> 
> Hmm.  This *might* be a bug caused by my compression bug workaround.
> 
> The printer (in "smartgdi" mode, which is the only documented mode for
> Samsung non-PCL printers) accepts a series of bands of compressed
> bitmap data.  Each band must be 64KB or smaller.
> 
> For bands which are larger than 64KB, there is a problem, as we have
> only the one known compression method.  So my workaround "fuzzes" the
> original print data and recompresses.  Basically it subtracts
> horizontal resolution iteratively until the band "fits" when
> compressed.  This is visible (mainly in dithered areas) as half-inch
> sized horizontal distortions on prints.
> 
> That said, your image doesn't really look like the distortion my hack
> introduces.  And many if not all parts of that test page should print
> without triggering my hack; usually only data like full-page-width f-s
> dithered areas don't compress adequately.  Ghostscript's internal
> halftoning is coarser than a straight 300dpi f-s dither, and rarely
> causes this issue.
> 
> I would suspect some other sort of problem, perhaps a resolution
> problem of some sort; I have never used the driver much at 300dpi.
> 
> Which exact driver version are you using?  The only way to really tell
> is probably to obtain the matching sources for your install
> ghostscript and inspect the gsdevgdi.c source directly.  Unless a
> Connectiva person can volunteer what they ship...

Sorry, I forgot to send it before. Here they are:
foomatic is 3.0.1 stable and the database is the snapshot from 20040219
and ghostscript is espgs-7.07.1.
I'm working at Conectiva, maintaining the printing system. I never went
that deep on ghostscript, but here I am. :)

> We should also verify that the driver is the problem and not foomatic
> (which has an increasing number of scarey driver output postprocessing
> features).  Can you print a 300dpi page successfully by invoking
> ghostscript directly from the command line into your printer's /dev
> node?

That I can't tell you right now, I need ask a person for the testing. I'll
reply again as soon as I get the answer, ok?

---end quoted text---

-- 
Marcelo Ricardo Leitner <mrl at conectiva.com.br>




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