[chbot] Vision processing side project.

Hugo Vincent chchrobotics@lists.linuxnut.co.nz
Wed, 23 May 2007 20:28:45 +1200


You might be interested in this, in case you haven't come across it  
already. There is a Mac OS X app called Books, that can read bar  
codes with the (pretty average) iSight webcams built into most modern  
Macs:

http://books.aetherial.net/wordpress/?p=420
http://www.bruji.com/cocoa/barcode.html

Although it says it doesn't work with built-in iSights (that have  
fixed focus, like most webcams, but unlike the original external  
iSights), I've tried it on my MacBook and it seems to work OK.

It's MIT licensed, so you might be able to use as-is if you have a  
Mac, but even if you don't, I'd imagine the algorithmic code is  
fairly portable. Let me know if you want help grokking Obj-C and/or  
Cocoa (although I don't have a clue about Carbon or Quicktime).

Cheers,
Hugo

On 23/05/2007, at 6:16 PM, Carl Ranson wrote:

> Andrew Errington wrote:
>
>> So, is the indicator line in the top right derived from the Hough  
>> Transform?  Does your demo run in real time (i.e. can you rotate  
>> the barcode and have the yellow line rotate accordingly)?
>>
>>
> If anyone just can't wait to see how it works, here's a good java  
> demo of the hough transform.
> http://www.cs.tu-bs.de/rob/lehre/bv/HNF.html
>
> Draw lines in the left pane then put the cusor over the bright  
> spots on the right pane. You'll see how things translate from  
> normal to hough space.
>
> Its a cool bit of maths. I really admire the sort of people who  
> dream this stuff up.
> CR
>
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