[Alexandria-list] Slovak translation and using a webcam as a barcode scanner

[Cathal Mc Ginley]

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On Mon, 2 Mar 2009 17:07:58 +0100 (CET)
kovac.peter at fotopriestor.sk wrote:

> Hi,
> 
> first of all, thank you for new version! It's nice to see that this
> project is still alive. :)
> 
> Next, I've just made Slovak translation of Alexandria 0.64b1 (see the
> attachment).

Thanks! I've just committed it to SVN, so it'll be in the final 0.6.4.
Make sure to join the alexandria-i18n-list too to be notified of
immanent releases and "string freezes". Welcome to Alexandria!

> 
> And another issue - I'm now a computer science student at Comenius
> University in Bratislava, Slovakia. This term every student chooses
> some interesting topic and makes a project about it (a piece of
> software or something like that). My project is to make webcams work
> as barcode scanners with Alexandria. I've googled for some
> webcam-to-barcode-scanner library and found Zebra
> ( http://zebra.sourceforge.net/ ). 

This sounds very cool! I was investigating Zebra just last night.
Lennart Karssen suggested it in Feature Request #23143 (from a
suggestion by Calors Garcia Saura). I managed to get the camera preview
working, but not scanning barcodes (I think it requires a webcam that
can focus... my Yeeloong netbook webcam probably has its focus fixed at
'infinity'.) Check that zebracam scans barcodes for you!

> It's written in C but I've read
> somewhere that it is possible to work with C libraries in Ruby.

Yep, it's how ruby-gnome2 does it. You might take a look at Ruby-Sexy,
( http://rubyforge.org/projects/ruby-sexy/ ) a small-ish project which
binds to the GTK widget extensions library Libsexy:
http://www.chipx86.com/w/index.php/Libsexy
That should give you a starting point for writing Ruby bindings.

Zebra also has bindings for Python which might help you too.

> I've an idea that encapsulating it as WebcamScanner class and registring
> it in Scanner Registry should make it (although I don't know how to
> make UI for it, but I hope it wouldn't be too hard). 

Actually that part would require some re-writing of Alexandria. The
current code only works for barcode scanners which provide data as if
they were keystrokes (To Alexandria, CueCats and standard keyboard wedge
scanners look like keyboards - with really fast typing of numbers).

However, I had been working (some months ago) with making this more
flexible, and wrote a client-server type setup for barcode
scanning. (I can't find it at the moment, but it was for some user's
expensive serial barcode scanner, that sub-project kinda went nowhere.)
I did have the framework set up, but that code never made it into SVN.
If I can dig it up again, I'll create an SVN branch for
"extended barcode scanner support" and you can work from that branch.

> Is this a good idea or should I try something else?

Basically, if you can get Ruby code to grab images from a webcam and
scan them with Zebra to produce the barcode number, Alexandria can be
modified to accept those scans.

It sounds like a great little project, if maybe a little tricky in
places. You'd have to check that whatever help I give in integrating
this code into Alexandria is in line with the University's rules for
computer projects.

Also, check if it will be possible for you to release the code to
Alexandria under the GPL when your project's finished? Even if not, the
process of writing it will make it easier to re-implement if neccessary
(you could just describe the approach you took).

Anyway, let me know if you need any further pointers. And I'll keep
you up to date on that SVN branch, if I can find that code...

   -   Cathal.
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