Newsgroups: sci.image.processing
From: AndyP@monitron.demon.co.uk (AndyPrior)
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!news3.near.net!noc.near.net!paperboy.wellfleet.com!news-feed-1.peachnet.edu!gatech!swrinde!pipex!peernews.demon.co.uk!monitron.demon.co.uk!AndyP
Subject: Re: Varying Grey-Scale Problem
References: <3flvf4$dnu@hermes.louisville.edu>
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Date: Mon, 6 Feb 1995 21:49:18 +0000
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Hi:

I am using the TM9700 too and have found that you have to be *extremly* careful to ensure you do 
 have a closed system. I would isolate the component first e.g.

1. Replace the camera with a 75ohm termination. Check for a difference.

2. Replace the camera with a test pattern generator. Check for a difference.

3. Cover the camera input with a lens cap. Check for a difference.

4. Check there is no chance that any florescent light is entering the 
lens. (My system was being affected by a light 25yds down a corridor. 
The strip-light flicker will be strobed by the field rate.)

5. Does the amount of noise change with illumination level? If so it 
could be imager noise. You could reduce this by cooling the ccd with 
(eg) a peltier cooler.

6. Is your software OK? Try it with a grabbed repeated frame.

7. If you can afford the system to be a bit slower average a few 
frames.

Good Luck
Andy Prior



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| AndyPrior    EMail AndyP@monitron.demon.co.uk                           |
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