🚀 go-pugleaf

In <jecome01.715798061@starbase.spd.louisville.edu> jecome01@rigel.spd.louisville.edu (Eric Comer) writes:
>	if the lens caps is place on a ccd camera and an image is capture,
>	why aren't all of the pixel values 0 (black)?  when the image is
>	normalized it seems like there are faint light diagonal lines
>	throughtout the whole image.  the image acquired was a gray scale
>	image the min value was 0 and the max value was 6.  any ideas?

Well, two things. The CCD doesn't need to give you a value of 0 without
light. This depends on the offset and gain of the video amplifier. Second,
your system obviously catches some periodic stray signal. If you know
your pixel rate then you can translate the number of pixels into the
offending frequency in the time domain. Most likely this will be a 60Hz
noise signal.

Regards,
-- 
Michael van Elst
UUCP:     universe!local-cluster!milky-way!sol!earth!uunet!unido!mpirbn!p554mve
Internet: p554mve@mpirbn.mpifr-bonn.mpg.de
                                "A potential Snark may lurk in every tree."