Re: [hylafax-users] Scanner to fax resolution problem

[Volker Kuhlmann <hidden@xxxxxxxxxxxxxxx>]

On Mon 12 Jan 2009 22:16:40 NZDT +1300, Frank Millman wrote:

> According to 'scanimage -h', both brightness and contrast are configurable
> on my scanner. In practice, if I try to vary contrast, I get the message
> 'attempted to set inactive option contrast'. I don't know why.

I doubt the scanner will do a monochrome scan. Instead, it'll do grey
scan, and then apply a simple threshold to get a binary value for each
pixel. In my experience, I have yet to see a scanning program which gets
the threshold right automatically. You want the paper colour to go
white, and medium blue lines to remain black. Manual adjustment is
invariably necessary.

xsane is about the best open source scanning program I could find, and
personally I don't find it usable. General confusion and bad UI are the
top items on my list. Your guess what scanimage does with the brightness
value.

If you want a really good scanning program, shell out for vuescan. It
doesn't do non-square resolutions though, so once you have your
monochrome bitmap image, you have to crank
imagemagick/netpbm/whateveryouwant to change to fax resolution.

Volker

-- 
Volker Kuhlmann			is list0570 with the domain in header
http://volker.dnsalias.net/	Please do not CC list postings to me.


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