Bad quality of photo printing under ubuntu

[Matthias Heiler]

Hi,

I'm trying to print photographs on a HP photosmart 8150.  This printer
is supposed to have good linux support (that's why I got it).

I'm using the recommended HP PhotoSmart 8100 Foomatic/hpijs driver in
CUPS.  Within KDE I open the photo with Gwenview and print it, using
the appropriate settings in the printer dialog that pops up.

Now the problems: 

(1) There are very thin horizontal _or_ vertical lines (depending on
    the setting Portrait/Landscape in the printer dialog).  I first
    suspected a hardware problem, but under Win the lines are gone.  I
    think they may represent boundaries of "chunks" that are processed
    independently and then sent incorrectly to the printer.

(2) Overall the pictures look average at best.  Looking closely one
    can see artifacts from the printing process.  The Windows-Prints
    (using HP's driver) are much better: Better colors, no artifacts.
    (I set all automatic image "optimizations" in the Win-Driver to
    off.)

Before ubuntu I used debian/testing.  My process there was to save a
PS under gimp and sent that one via cups to gs/hpijs.  While this was
a horrible process (you had to calculate scaling factors and click a
zillion times; gimp printing doesn't work with HPs since there's some
automatic gamma correction going on that is calibrated for Epsons) the
pictures at least weren't plagued by stripes.

Has anyone a hint what I could try to change?  What would be the
appropriate place for a bug report?

Thanks,

  Matthias