[sane-devel] Linotype X-ray Scanner

[Oliver Rauch]

When you do not use any gamma table options it is ok.

SANE supports images with a color depth of 8 or 16 bits/sample.
A 12 bit sample does use 16 bits (2 bytes). The raw data of UMAX
or Linotype scanners already is transfered from the scanner to the
backend in this format. It is the raw format of the scanner.

Best regards
Oliver

Piernicola Oliva schrieb:
> 
> I'sorry, I'm a beginner and I'don't know how to disable gamma table
> (something like --gamma-table 0?).
> 
> What do you mean with 'a maximum next to 65535.'?
> I am expecting values from 0 to 4095 (12 bit). I'm not interested in
> mulitipling factors or correction for visualization algorithms, I would like
> to obtain the raw data from the scanner, because I need them for another
> software.
> 
> I'll try to explain better my problem:
> I'm going to use this scanner with radiographic films, in order to produce
> images for a Computer Aided Detection system.
> The CADe requires 12-bit images, with pixel values ranging from 0 to 4095.
> This system itself acquires images using the command (with sane 1.0.4)
>  scanimage -d umax:/dev/sgb --source Transparency Adapter --resolution 300dpi
> -l 30 -t 10 -x 175 -y 225 --depth 12
> and produces 12-bit images (ranging from 0 to 4095 for each channel) (An
> example: for a particular film i obtained histgram values significantly
> different from 0, for channels from 0 to 2650, for each color channel)
> Using the same command with another linux system on the same computer (and
> the same scanner) and sane1.0.9 I obtained for the same image, with the same
> command,  the same histogram shape, with values from 0 to 2650, but only 165
> channels are different from zero (only one channel in16 is different from
> zero)  - this means that the 'true' image I'm obtaining is 8bit.
> 
> Somebody told me that sane has been modified on the linux that produces 12bit
> image, but I couldn't find any (modified) source on that computer. Is it
> possible?
> 
> Thank you very much,
> Piernicola
> 
> On Thursday 14 November 2002 23:00, you wrote:
> > Hello.
> >
> > --depth 12 is correct, but this normally produces values
> > with a maximum next to 65535. If you get values small than
> > 4095 then it looks like you use a bad gamma table.
> > Disable the gamma table as a first test.
> >
> > Bye
> > Oliver
> >
> > Piernicola Oliva schrieb:
> > > Hi,
> > > I'm working with a Linotype Saphir2 X-ray Scanner.
> > > I'm trying to obtain 12bit images (--depth 12), but I only obtain 8bit
> > > (multiplied by 16) pixel values.
> > > How can I obtain 'true' 12bit images?
> > > Thanks,
> > > Piernicola

-- 
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E-Mail:		mailto:Oliver.Rauch@rauch-domain.de