18
2.2.3 PTZ cameras and PTZ dome cameras
A PTZ camera or a PTZ dome camera can manually or automatically pan, tilt and zoom in and
out of an area or object. All PTZ commands are sent over the same network cable as for video
transmission;
no RS-485 wires need to be installed as is the case with an analog PTZ camera.
Some of the features that can be incorporated in a PTZ camera or a PTZ dome camera include:
>
Electronic image stabilization (EIS).
In outdoor installations, PTZ dome cameras with zoom
factors above 20x are sensitive to vibrations and motion caused by traffic or wind. EIS helps
reduce the affects of vibration in a video. In addition to getting more useful video, EIS will
reduce the file size of the compressed image, thereby saving valuable storage space.
>
Privacy masking.
Privacy masking, which allows certain areas of a scene to be blocked or
masked from viewing and recording, can be made available in various network video
products. In a PTZ camera or PTZ dome camera, the functionality has the ability to maintain
the privacy masking even as the camera’s field of view changes since the masking moves
with the coordinate system.
Figure 2.2c With built-in privacy masking (gray rectangle in image), the camera can guarantee privacy for areas
that should not be covered by a surveillance application.
CHAPTER 2 - NETWORk CAMERAS
