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Subject: Re: Number Plate Recognition
Date: Mon, 11 Aug 2008 11:17:01 +0000 (UTC)
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"David " <dave@bigcompany.com> wrote in message 
<g7p2dd$fsr$1@fred.mathworks.com>...
> "Prasenjeet Patil" <prasenjeet.patil@hotmail.com> wrote 
in 
> message <g7omd3$2i7$1@fred.mathworks.com>...
> > I am doing the same project, but i am stuck at the 
> method to
> > use.If u have got the code plz share it with me.We can 
> have
> > good conversation o this topic.
> > Thanks & regards.
> > 
> 
> have you figured out the mud on the plates problem?

Here is a good bit of Pucka gen to help you with this 
problem.

1) Don't use ambient light to illuminate the number plate - 
use a low pressure Sodium discharge lamp.

2) Put a narrow band optical filter in front of your camera 
lens, which only passes the Dominant Sodium D lines from 
your source.

3) The sun emits no radiation in the Sodium D lines as it 
coincides with a Fraunhofer absorbtion line (The Sun 
contains Sodium in its atmosphere!).

4) This way - subject to you having a narrow illumination 
beam virtually removes all image clutter making it much 
easier to identify the numberplate from other objects in 
the scene.

5) Because you are supplying the illumination, and getting 
nothing from the ambient light, your camera exposure is 
fixed.

6) Its a good stunt for detecting sea skimming missiles to.

Dave Robinson 

p.s. doesn't do anything for the Mud :-(