RE: [hpoj-devel] preliminary PML/scanning support

[PASCHAL,DAVID (HP-Roseville,ex1) <dav...@hp...>]

Joe Piolunek wrote:
> I was able to scan with the 600 using the simple command 
> 'ptal-hp mlc:par:0 
> scan'. The resulting "out.pnm" file printed, but was very 
> dark compared to 
> the original. 
Hi, Joe.  Thanks for the success report.

-bw mode (the default) is technically referred to as "bi-level threshold",
which results in either black or white, depending on the threshold.  You
might be able to adjust the threshold by experimenting with the "-contrast"
switch, although I haven't tried this myself.  You could also try using
"-bwht", which is "halftone" instead of "threshold".  Supposedly this means
that the device does some dithering to simulate shades of gray, although
I've never noticed any difference in practice, for devices which support
this option.

> I'll be glad to see color scanning arrive, if you can get it working.
I'll get it working one way or another.  It turns out that grayscale and
color scanning on these models forces the device to return a JPEG-compressed
image.  At the moment I'm trying to figure out what I need to morph in the
data stream to produce a valid .jpg file, as opposed to a .pnm file.

David