
How Motion Detection Cameras Work - abennett
http://www.itworld.com/it-managementstrategy/94960/how-motion-detection-cameras-work
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ilamont
_"However, CCD produces higher quality images. Thus, security cameras
generally use CCD technology."_

Assuming this statement is true, then why is it often difficult to make out
suspects in security camera footage shown on TV news reports? The classic
example is a case involving a theft or other crime at a mall -- facial
features are never clear. Banks, however, seem to always have good images
available when robberies take place. Is it an issue of placement, older
technologies, or something else?

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brk
This article is actually very poorly written. For starters, one of the best
CCTV image sensors on the market is from a company called Pixim, and it is
CMOS, not CCD.

The vast majority of CCTV cameras sold today are D1 (VGA) resolution. They are
also often covering fairly large fields of view, so you end up with a few
dozen pixels on target of someones face, or a license plate. It's impossible
(other than on TV) to extrapolate that into useful detail.

The "motion detection" systems described in this article are also false-alarm
generating garbage in most cases. You need a camera that can definitively
recognize and detect people, plus have some ability to a behavior analysis
(direction of travel, loitering,etc.).

An example from an actual camera on my driveway (with the Pixim CMOS sensor):
<http://www.youtube.com/videoiq#p/u/6/FbAWYB24Qdw>

Track the _person_. Not the dogs, not the water, not the shadows.

