BarcodeScanner --reads the incoming camera image and converts it to an optimal brightness contrast for reading
BarcodeValidator -- excepts a string of 12 or 13 numbers which it will validate as a correct UPC-A or EAN-13 barcode
BarcodeReader -- extends Barcode Scanner and extracts the barcode from the current frame of the BarcodeScanner. It then does a lookup on a table and converts the image into a series of numbers which are fed to the BarcodeValidator.
BarcodeErrorCorrection -- evendently if one of the 12 numbers is wrong you can use a lookup table based on an algorythm to determine a colum and row of the incorrect digit. You can then use that number to find the correct digit. I have the look up table in place from a sample though I have not integrated it into the classes yet.
So everything is working pretty well EXCEPT that the scanner is pretty unforgiving. Typically, the way a barcode readers works is you have registration markers at the ends and middle of the barcode (they are two thin black lines with an equal sized bar in the center). Scanning either left to right or vice versa you can determine if you are inside a barcode. Unfortunatly for me the calirty of a standard web cam is not very percise and what I need is a way to perform a "most likely" match on these images.
What I mean is if I found a bar I could consult my look up table and say this bar is most like 001011 which is 1 scanning left.
What I am experimenting with now is taking several slices and smashing them together to get an average. Then I crawl this averaged slice and try to find the bars in the barcode.
Does this sound like the best way to go about it?
I am happy to upload what I have so far (including unit tests) if anyone is interested.
Thanks,
Mark
On 9/8/05, M Daggett <[EMAIL PROTECTED]> wrote:
I think this is the same barcode reader, though the author says
"another barcode reader example". I could not find the former on his
site. Good news is that I found an excellent explanation of how a
barcode is decoded so I think that I have most of the info I need to
start writing my little project. Once I get something actually
"working" regardless of how kludgy it is I'll be sure to pass it along
to the list (even if it is just good for a laugh).
Thanks everyone for giving me a diversion this weekend, otherwise I
would have been forced to get fresh air and sun with my wife!
Later,
Mark
On 9/8/05, franto <[EMAIL PROTECTED]> wrote:
> here in comments is another barcode reader
>
> http://www.franto.com/blog2/maelstrom-webcam-scanner
>
>
> On 9/7/05, M Daggett < [EMAIL PROTECTED]> wrote:
> >
> > Hey Robert and Darron,
> > Thanks for the note. Yes, I was pretty sure someone had to already
> > have cracked this particular nut. Though I think it would be really
> > great to do it as an OS project so I will probably give it a shot
> > anyway. The image normalization should be pretty straight forward, I
> > did lots of this in Director when that was all the rage. Essentially I
> > think the best thing would be to do the machine vision through the
> > flash presentation layer and then tie it into the server for the
> > domain layer stuff (that way you can separate it for the particular
> > task at hand).
> >
> > I'll keep you posted,
> > Mark
> >
> >
> > On 9/7/05, Robert M. Hall <[EMAIL PROTECTED] > wrote:
> > > I have been in touch with Chris Benjaminsen the creator of the
> barcoder.nu
> > > website.
> > >
> > > He will probably have some announcements about this later in the month
> or
> > > near mid October.
> > >
> > > I'll be demonstrating some laser based barcode readers interacting with
> > > Flash during my presentation at MAX 2005, as well as some pure code base
> > > stuff based on what Chris put together for the barcoder.nu site - but it
> > > would be great if someone else put together some alternative classes to
> what
> > > is out there - especially if they were open source.
> > >
> > > Go for it M! If you get something finished before Oct 15th, and its
> > > opensource, let me know and I'll be happy to show a comparison in my
> > > demonstration of similar methods.
> > >
> > > Regards,
> > > Rob
> > >
> > > > From: "Darron J. Schall" < [EMAIL PROTECTED]>
> > > > Reply-To: Open Source Flash Mailing List < [email protected]>
> > > > Date: Wed, 07 Sep 2005 13:21:12 -0400
> > > > To: Open Source Flash Mailing List <[email protected] >
> > > > Subject: Re: [osflash] possible project?
> > > >
> > > > M Daggett wrote:
> > > >
> > > >> I was thinking about the new pixel level
> > > >> control of flash and was thinking that it would be possible to make a
> > > >> barcode reader using a web cam (much like delicious library does for
> > > >> the mac). Would this be useful to anyone, do you know if said classes
> > > >> already exist?
> > > >>
> > > >>
> > > >
> > > > Something like this was already created at: http://www.barcoder.nu/
> > > >
> > > > However, it doesn't appear to be open source.
> > > >
> > > > -d
> > > >
> > > >
> > > > _______________________________________________
> > > > osflash mailing list
> > > > [email protected]
> > > >
> http://osflash.org/mailman/listinfo/osflash_osflash.org
> > >
> > >
> > >
> > > _______________________________________________
> > > osflash mailing list
> > > [email protected]
> > > http://osflash.org/mailman/listinfo/osflash_osflash.org
> > >
> >
> >
> > --
> >
> --------------------------------------------------------------------
> > I am Mark Daggett and I approve this message.
> >
> > _______________________________________________
> > osflash mailing list
> > [email protected]
> > http://osflash.org/mailman/listinfo/osflash_osflash.org
> >
>
>
>
> --
> -------------------------------------------------------------------------------------------------------------------------------------------------------------------
> Franto
>
> http://blog.franto.com
> _______________________________________________
> osflash mailing list
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>
>
>
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