Raster Low Quality

Michael Sweet mike at easysw.com
Wed Apr 13 08:16:01 PDT 2005

Andrew wrote:
> I used the cups-1.1.23 code (imagetoraster.c, rastertoepson.c etc...)
> - as filter to produce raw Esc/P 2 data for the Epson Stylus Photo R200 printer - on the base of the supplied stphoto.ppd file.
> All worked alright except I only got rather mediocre image quality.
> Besides it rather looked like the resolution had nothing to do with the problem: something like rather crude rasterization grid/pattern was clearly seen at any (720 dpi for instance) resolution.
> Perhaps anybody could tell me whether it's an intrinsic limitation of the implementation or it could be solved somehow (for instance by getting a more specific ppd for the printer model or by correcting it somehow - however unlike it does seem considering the code).
> I'd greatly appreciate any ideas - I've already parsed the source code to a considerable extent so I expect to get quite specific ones too.

The rastertoepson driver only uses 1-bit per color data (it is
meant as a "get up and running to do basic printing" driver, not as
a photo-quality driver), so you aren't seeing anything unusual.

The CUPS DDK driver for the Epson printers provides much better
quality, and the Gimp-Print (now Gutenprint) drivers also provide
better quality:


Michael Sweet, Easy Software Products           mike at easysw dot com
Internet Printing and Document Software          http://www.easysw.com

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