Motion detection is the process of detecting a change in the position of an object related to its environment or its relative changes to an object. Motion detection can be achieved by mechanical or electronic methods. When motion detection is performed by a natural organism, it is called motion perception.
Video Motion detection
Metode
Motion can be detected by:
- Infrared (passive and active sensor)
- Optical (video and camera system)
- Radio Frequency Energy (radar motion detection, microwaves, and tomography)
- Sound (microphone and acoustic sensor)
- Vibrations (triboelectric, seismic, and inertia-switch sensors)
- Magnet (magnetic sensor and magnetometer)
Mechanical
The most basic form of mechanical motion detection is in the form of a switch or trigger. For example, typewriter keys use mechanical methods to detect motion. Each button is a manual switch that is on or off. Each letter that appears is the result of movement on the key in question and the key is turned on.
Electronics
The main methods in which movement can be identified electronically are optical detection and acoustic detection. Infrared light or laser technology can be used for optical detection. Motion detection devices, such as PIR motion detectors, have sensors that detect interference in the infrared spectrum. Once detected, the signal can activate an alarm or camera that can capture images or videos from movement.
The main applications for such detection are the detection of unauthorized entries, the detection of a region's occupancy detention to extinguish the lighting, and the detection of moving objects that trigger the camera to record the next event.
The simple algorithm for motion detection by the camera still compares the current image with reference images and only counts the number of different pixels. Because images will differ naturally due to factors such as varying illumination, camera flashes, and CCD dark currents, pre-processing is useful for reducing the number of false-positive alarms.
More complex algorithms are needed to detect motion when the camera itself is in motion, or when the movement of a particular object must be detected in a field containing other negligible motions. An example might be a painting that is surrounded by visitors in an art gallery. For the case of moving cameras, models based on optical flow are used to distinguish between clear background movements caused by camera movements and independent objects moving on the scene.
Maps Motion detection
Device
Motion detectors are devices that detect moving objects, especially people. Such devices are often integrated as components of a system that automatically performs tasks or notifies users of movement in an area. The occupancy sensor detects the presence of an entity in a given space.
Motion controls are also used for video games consoles as game controllers. The camera can also allow body movement to be used as an input device, such as in the Kinect system.
References
External links
- Relational Motion Detection
- www.cs.rochester.edu/~nelson/research
- Motion Detection Algorithm In Image Processing
- Motion Detection Research and Introduction
- Attendance and Absence Detection is explained
- Video realization of motion detection realization algorithms
Source of the article : Wikipedia
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