[sane-devel] HP5470c scanner nearly working!

Thu Feb 20 12:30:22 GMT 2003

Yeah, I saw the project but there did not seem to be anything happening.
However, the hp5400-20021018.tar.gz did form the basis for my program.

Thanks for your report of success. Seems only the version numbers are slightly
different.

Anyway, I've decoded the images and it now saves them to disk as PPM files.
If you scan anything with a lot of white you can see that the calibration
(and gamma correction) definitly needs some work. I have some theories about
how to get the figures but I havn't done it yet. Interestingly, the full
preview image includes a section which is within the case itself. Looks like
some test areas and other odd stuff going on there. I've put the image up
here: http://svana.org/kleptog/hp5470/output.png (1MB).

I've not used sourceforge much, so I'm not quite sure what that entails.
What I would like is information on how to write a SANE backend. I've
downloaded the source but there does not seem to be any kind of skeleton or
documentation on how to write a backend. What I've got is easily good enough
to pass for "beta" in a SANE backend.

Anyway, I've put a new version up on my site
(http://svana.org/kleptog/hp5470/). Let me know if the images come out OK.
My xview is having problems showing 48bpp PPM images so you may have to
convert them to PNG to make them viewable.

Let me know how it goes.

On Thu, Feb 20, 2003 at 09:13:47AM +0100, Thomas Soumarmon wrote:
> 
> Hi Martijn,
> 
> I began about one month ago to do the same work you've done. Unfortunately 
> about 2 weeks after the beginning my spare time reduced a lot, so I must say 
> that it slowed down a lot, reaching a 0 speed for about 1 month.
> 
> There is now a Sourceforge project set up for hp5400 series SANE backend : 
> http://sourceforge.net/projects/hp5400backend/
> and 
> http://hp5400backend.sourceforge.net/
> I hope you can get some information there.
> 
> I think it would be worse you add your work on that project. As you might have 
> more time than I, would you want to be added as an administrator on that 
> project ?
> 
> Another thing. The test program you wrote compiled perfectly and appearently 
> worked ok. I email you the log directly.
> 
> Have a nice day.
> 
> 
> Le Mercredi 19 Février 2003 23:52, Martijn van Oosterhout a écrit :
> > [Please CC any replies so I can more easily find them through the rest of
> > my mail. Thanks.]
> >
> > I finally got totally sick of waiting for someone to make my scanner work,
> > so I did it myself. The results are on my webpage:
> > http://svana.org/kleptog/hp5470/. I'm doing it over USB.
> >
> > Situation is:
> > 1. It finds the scanner and warms up the lamp
> > 2. It performs two calibrations scans like in windows
> > 3. Performs the preview scan and dumps it to disk
> >
> > This is only a test program, not a backend. Things still to do:
> > 1. Actually use results of calibration scans. Anyone who has an idea how
> > scanners are calibrated, point me at some info, please.
> > 2. Do gamma correction. Right now the gamma correction is linear. Again,
> > someone who knows the theory would be helpful here.
> > 3. Decipher data format. Looks pretty straight forward. R, G, B seperate.
> > 4. Work out the parameters for the different scan types (B&W, 24-bit, etc).
> > 5. Turn it into a SANE backend. Hopefully this will not be hard.
> > 6. Make negative/slide addon work.
> >
> > Hopefully not far to go now. If anyone can test my code it would be much
> > appreciated. Note this version produces a *lot* of debug info. Please send
> > it all for bug reports. Thanks.
> >
> > I'd like to thank Bertrik Sikken for doing some of the ground work.
> >
> > Have a nice day,
> 
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-- 
Martijn van Oosterhout   <kleptog at svana.org>   http://svana.org/kleptog/
> Support bacteria! They're the only culture some people have.
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