🚀 go-pugleaf

Bradley Rosser (brad@pinerivers.qld.gov.au) wrote:
: In NETPBM I use something like the following pipeline to create a
: scaled up output image for a HP Laserjet 3 from a scanned PCX 
: input file:

:   pcxtoppm FILE | pnmscale -xysize 2330 3350 | ppmtopgm | pgmtopbm |
:        pbmtolj -resolution 300 > LASERIMAGE

: and when I print the image to a Laserjet 3 the result is most
: definitely of lesser quality than the same PCX file printed to a "HP
: Laserjet 3" driver in PhotoFinish, an MS Windows program that
: I use.  The PBM output has little patterns
: in what should be (and is in the PhotoFinish output) an even pattern
: of gray.

You may want to use one of the other dithering options available in
pgmtopbm - AFAIK the default Floyd-Steinberg dithering algorithm can
produce moire patterns, which make the output lower quality.

FS and other error diffusion algorithms aren't good for a simple
laser like the HP laser jet (is the output darker than you expect?).
You probably need to use one of the clustered dots dithers.

-- 
        Tony Cook - tony@online.tmx.com.au
                    100237.3425@compuserve.com