Newsgroups: sci.image.processing
From: Steve@dstrip.demon.co.uk (Steve Rencontre)
Path: cantaloupe.srv.cs.cmu.edu!das-news2.harvard.edu!news2.near.net!news.mathworks.com!udel!gatech!swrinde!pipex!peernews.demon.co.uk!dstrip.demon.co.uk!Steve
Subject: Re: why noise pattern same on adjacent scanlines
References: <3gm2lo$ova@news.parc.xerox.com>
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Date: Mon, 6 Feb 1995 16:10:33 +0000
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In article: <3gm2lo$ova@news.parc.xerox.com>  macleod@EuroPARC.Xerox.COM (Donald Macleod) writes:
> 
> Hello
> I am grabbing pixmaps containing well-defined features with a
> typical small CCD camera (Hitachi KP-111).
> When I look at adjacent scan lines e.g. x = 100 and x = 101, the
> noise pattern is very similar, so that it will not cancel out on
> averaging over a number of adjacent lines. I had to implement my own
> smoothing algorithm. Anyone know what is the technical reason
> for this phenomenon? It happens in both x and y directions. Have
> also tried another KP-111 camera, but not a different camera.

If it's a colour camera and a mono capture board, you may be having 
problems with the colour signal not being filtered out properly. This 
will give you systematic rather than random errors.

Similarly, you could be getting interference from the system clock or 
suchlike.

BTDTGTTS :-)

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Steve Rencontre               |  steve@dstrip.demon.co.uk (business) 
If it works, it's obsolete.   |  steveren@cix.compulink.co.uk (private)
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