Dvr Motion Detection

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There are many different ways to detect motion with digital video security cameras including Digital Video Recorder or DVR motion detection. Motion detection may be used in about as many different ways for as many different purposes as there are ways to detect it. In the following article we are going to talk about a couple of different methods used for motion detection but our main emphasis will be on DVR motion detection.



Let's begin our discussion with the motion detection cameras, and then we'll talk about the DVR.



A PIR sensor detects the average infrared or heat signature for the camera's general field of view. These sensors are normally used for the purpose of turning the camera on and off. If something causes an abrupt change in that heat signature, such as a human or animal passing by, the PIR sensor detects the sudden difference in the average heat signature and assumes this is caused by someone or something in motion.



The PIR motion detector is connected to a relay which turns the camera on and off. Quite often you will find these PIR ...
... sensors on cameras that are battery operated. Since the PIR consumes a fraction of the power that recording a video image requires, it greatly conserves on power allowing for greater time between replacing and recharging batteries.



DVR motion detection works on a totally different principle and usually for a different result. A DVR motion detection works by constantly analyzing the tiny dots or squares called pixels that comprise the camera's entire field of view. Provided these pixels do not change in appearance (color, brightness, etc.) the DVR assumes that there is no motion at the current time.



However, should a close grouping of the pixels change, especially if they change drastically and rapidly, the DVR interprets this to mean that there is motion is the camera's field of view. Generally, for DVR motion detection this is used for two different applications.



The first is analogous to the example already sighted above with the camera using a PIR sensor. In this case, the camera(s)) are left in a constant state of being On however, the DVR is not recording any of the camera's activity. However, when the DVR detects motion, it may be programmed as a trigger to start recording with that camera.



DVR motion detection helps to conserve on Hard Disk Drive or HDD storage capacity or disk space. Even though the cameras are in a constant On state, the DVR is not recording unless motion is detected. In a relatively low movement environment, this can make an HDD lasts for days, weeks, or months before it needs to start overwriting earlier files do to storage on the disk reach full capacity.



However, that is just one example of using DVR motion detection. Another more intricate and advanced capability using DVR motion detection is track or follow. You must have a Pan-Tilt-Zoom or PTZ camera for this function. For track and/or follow the PTZ camera will automatically Pan, Tilt, or Zoom to get the best shot of the moving object. It does this using DVR motion detection. It also gives the user the power of multiple cameras when only one PTZ is used.



This is great for store parking lots (every mall or large retail store should be required to have such a parking lot monitor), church parking lots, school parking areas, and many other locations where people, pets, vehicles or other objects need to be tracked within a certain range of the camera.



Track and follow may be possible with the PTZ camera controlling the tracking or following of the object, but generally speaking most premium systems will use the DVR motion detection and track or follow programming. The DVR accomplishes this be monitoring the pixels that are created with the field of view is captured by the lens and sent to the camera's sensor.



If the DVR detects a group of pixels that are moving across the screen it triggers its track or follow function (This is an over simplified description of a complex process. For example the pixels don't really move across the screen, the image moves across the stationary pixels.) sending the necessary commands to the PTZ camera to begin the track or follow process.



If you have any addition questions concerning DVR motion detection an what it could do for you, please contact one our security experts via on-line Live Chat or by telephone at 866-573-8878