Mike Macgirvin
Diary and Other Rantings
Beyond Silicon Valley
   
Wednesday, Jul 09 2008, 01:14 pm
Oct 16, 2006
Fuzzy Tools

I've been watching the whole bruhaha at Seattle911.com with some interest. This is a homegrown website that takes live 911 feeds and puts them on a Google mashup. Cute and clever use of technology. The Seattle Fire Department responded by changing the logs to image format rather than text.

That's the background. Reading some of the articles pointed me to 'gocr' which is a free OCR package. Now this is useful - I wasn't earlier aware of its existence. It basically takes an image and tries to distinguish text in the image and gives you the text. If you saw my article on comment spam, you'll realize that 'captcha' images to prevent spam are doomed. This is where you type into a box the letters you see in the picture. Most of these are annoying anyway, but it's pretty hard to get them through a clever command-line driven OCR program. If you make it so hard to read that gocr can't read it, chances are that none of your audience will be able to either.

But I have an even deeper interest in this stuff.  Gocr is a framework for finding recognizable stuff in images. Something the world has needed for a while now is something that can filter porn. In theory there isn't much difference between distinguishing the letter 'b' in a picture (in any of 600 different fonts) and say a breast (in any of 600 different sizes/shapes). I'm being polite. Any anatomical feature. 

Some folks worked on this problem back in the '80's, correlating the prevalance of what could be termed 'skin tones' in an image.

The tools and concepts are out there. It shouldn't take much more than a man month or three to put them together into a porn filter. There's probably a market for such a thing.

OK, gocr is probably encumbered with the GNU General Public License. So maybe there isn't much of a market unless one just uses the general pattern recognition concepts (but not the code) and starts from scratch. I don't have anything against the GPL. It serves its purpose, but it does make it hard to re-use code in the workplace. It's a bummer to always have to start from scratch, when the software already exists and has been pretty much debugged. If I'm releasing code into the public domain, I always use either the Berkeley/Stanford license or no license at all. Free, no warranty, blah blah. The GPL is basically a self-replicating virus - which was written by lawyers instead of geeks. 

 

Comments:

mike
February 22, 2008 14:54
mike

gocr, is rubbish. it's been around forever and is still rubbish. it cant read clear text reliably how could it foil capcha? It's funny your article is about filtering porn too.. i just read today about a flop of a program australia spent what? 85million on that a kid (who it was meant to protect) circumvented in what? minutes? stop wasting your time! ahah

 

oh my, i read the rest of the post. at first i thought you were only misinformed, but you're clearly an idiot. :( poor guy.


mike (Mike Macgirvin)
February 22, 2008 20:03
[*TOP MEMBER*] mike

Ya' know I was going to agree with you that gocr is absolute junk, which I found out after fifteen minutes of evaluation back in 2006. It doesn't do any kind of fuzzy match and just looks at pixel comparisons in functions something like compare_a(), compare_b(), etc. Hardly general purpose pattern matching algorithms. I've since posted about doing this kind of pattern matching with heuristics, but it really doesn't matter because then you went into name calling and insult mode and I really don't owe you the time of day. 

Building software involves taking into account a great many factors - of which the license terms can be important if you're (as I was at the time) working for a corporation that has banned anything tainted with GPL. These employers leave you no choice but to build from scratch - which isn't a problem if you're any good at the job and want to continue receiving a paycheck. I do know a bit about the GPL - I've worked with it since the first draft of the license back in the late 80s. I choose not to use legal atrocities like this for my own projects. This makes them legally usable by more people than so-called 'open-source'. 

Bugger off.


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Oct 03, 2006
First day of work

Started the new job today. I'm working for a large PC security firm doing web stuff.

That's about all I can tell you right now. 

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