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2.5
Guidelines for selecting a network camera
With the variety of network cameras available, it is useful to have some guidelines when
selecting a network camera.
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Define the surveillance goal: overview or high detail.
Overview images aim to view a scene
in general or view the general movements of people. High detail images are important for
identification of persons or objects (e.g., face or license plate recognition, point-of-sales
monitoring). The surveillance goal will determine the field of view, the placement of the
camera, and the type of camera/lens required.
For more on lenses, see Chapter 3.
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Area of coverage.
For a given location, determine the number of interest areas, how much
of these areas should be covered and whether the areas are located relatively close to each
other or spread far apart. The area will determine the type of camera and number of
cameras required.
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Megapixel or non-megapixel.
For instance, if there are two, relatively small areas of
interest that are close to each other, a megapixel camera with a wide-angle lens can
be used instead of two non-megapixel cameras.
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Fixed or PTZ.
(In the following context, fixed cameras refer also to fixed domes
and PTZ cameras refer also to PTZ domes.) An area may be covered by several fixed
cameras or a few PTZ cameras. Consider that a PTZ camera with high optical zoom
capabilities can provide high detail images and survey a large area. However, a PTZ
camera may provide a brief view of one part of its area of coverage at a time, while a
fixed camera will be able to provide full coverage of its area all the time. To make full
use of the capabilities of a PTZ camera, an operator is required or an automatic tour
needs to be set up.
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Indoor or outdoor environment.
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Light sensitivity and lighting requirements.
In outdoor environments, consider the use
of day and night cameras. Consider the light sensitivity of the camera required and
whether additional lighting or specialized light such as IR lamps is needed. Keep in
mind that lux measurements on network cameras are not comparable among different
network video product vendors as there is no industry standard for measuring light
sensitivity.
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Housing.
If the camera is to be placed outdoors or in environments that require protec-
tion from dust, humidity or vandalism, housings are required.
For more on housing, see
Chapter 4.
CHAPTER 2 - NETWORk CAMERAS
