What is the PTZ Camera?
PTZ is an abbreviation for pan, tilt, and zoom which reflects the movement options of the camera. A pan–tilt–zoom camera (PTZ camera) is a camera that is capable of remote directional and zoom control.
You can physically control the camera horizontally or vertically using electrical motors. The zoom is controlled by mechanically moving two lenses closer together or further apart dependent on whether you are zooming in or out with the effect that objects in view appear larger or smaller.
With these cameras you can now capture footage from 360° around the camera and digitally zoom in on certain areas. Because you are recording the entire field of view it doesn’t matter if you are zoomed in on the entry gates or not, all angles are recorded.
Pan and Tilt Control
On a conventional PTZ camera, when you pan and tilt you physically rotate the camera using electrical motors i.e. pan (horizontally) or tilt (vertically).
The movement of the motor could be controlled relatively or absolutely and this is depending on how much you want the camera to move steps or degrees. In addition to controlling the speed of the move.
The Pan and tilt motors also could have the signal to move without stop horizontally or vertically.
In the Mechanical PTZ Cameras, zoom is controlled by mechanically moving two lenses closer together or further apart dependent on whether you are zooming in or out with the effect that objects in view appear larger or smaller.
Digital PTZ cameras don’t work in this manner. The camera will first capture a full image, usually in megapixel resolution. When a user decides to zoom in they are provided with a section of the overall picture. The pixels in this are then enlarged so that the cropped image is the same size as the original. This gives the appearance that you have zoomed in as objects are now larger.
Controlling the PTZ Camera
PTZ cameras could be controlled by any of the following ways
- Control the PTZ camera by its remote control, not all vendors support remote controls and not all cameras support remote controls.
- Controlling the PTZ camera by COM ports and it work with one of the following protocols PelcoP, PelcoD and VISCA
- Controlling the PTZ camera by USB and it work with UVC and this can use some components like DirectShow.NET
We can implement the software component to control the camera using C++ and C#
Other Cameras’ Types
As stated earlier, conventional PTZ cameras use motors to move the camera around. There are multiple different ways of using these to pan the camera such as bands, cogs or direct drive. There are even some which use electromagnetism to accurately aim the camera in some higher end cameras.
Digital PTZ systems perform their functionality in software. As a result there are no moving parts and nothing to break, freeze or move. So long as the camera is functioning, the digital PTZ system will work. So from a reliability point of view, digital PTZ cameras win hands down.
(Source: Network Webcams)