HylaFAX The world's most advanced open source fax server

[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: [hylafax-users] pdf poor quality images when i send.

On Sat, Dec 13, 2008 at 9:14 PM, <l.mannucci@xxxxxxxxxxxxxxx> wrote:
Hi David,
how i can modify the quality of pdf to HylaFax? there is a file for modify
the quality? The Board is DIVA ISDN 4BRI, if you want i can send to you the

>> I will use avantfax web for convert .pdf and send directly to hylafax.
The poor quality it's only when i send trught avantfax to a my fax
>> I hope avantfax use ghotscript driver to covert.
>> It's possibile to change the quality on the avantfax or hylafax?

If you send the same PDF from the command line
$ sendfax .......
is the quality the same (bad)?

If so, then the problem is in the dithering done through ghostscript during the conversion PDF.

In my HylaFAX install I can read this in

    # Ghostscript's default dithering with the fax drivers is
    # usually unsatisfactory.  So we have an option to process
    # the image through libtiff's Floyd-Steinberg dithering.
    # This will be a bit more costly on CPU and image preparation
    # time... enable it cautiously.
    # An alternative to libtiff Floyd-Steinberg dithering would
    # be to use a threshold array based stochastic mask within
    # Ghostscript.  However, this alternative may perform less
    # than ideally on unmodified Ghostscript versions prior to 8.62.
    # See: http://bugs.ghostscript.com/show_bug.cgi?id=689633


Project hosted by iFAX Solutions