Motion tracking is a technique that can be used for a number of different purposes, each of which may call for a varying degree of complexity. The basic idea behind motion tracking is that video frames can be analyzed in order to follow the position of an object through time. This can be useful for detecting the presence of any motion, such as in a surveillance system, or for the complex motion capture used in video editing. Motion tracking can also be used as an alternative to radar to follow distant objects, such as missiles, satellites, and space debris, while also providing a high resolution image.
The simplest form of motion tracking is typically used in surveillance systems. Rather than tracking the position of an object over time, these systems generally use some form of technology to sense the presence of motion to activate a video camera, recorder, or alarm. Infrared light or lasers are often used to sense motion in the form of a tripwire system, though video can also be analyzed for movement in order to trigger a recording or sound an alarm.
More complex types of motion tracking are designed to identify an object and follow it through consecutive video frames. In order to accomplish this, some type of computing device typically uses an algorithm to analyze each frame. An algorithm such as blob tracking can be useful for following human movement or any other object that can present a dynamically changing profile. Contour tracking is another type of algorithm that typically looks for and examines the outline of an object. More processor-intensive methods, such as kalman or particle filters, can be useful for following complex interactions, such as the tracked object moving behind an obstruction.
One common use of motion tracking is in video editing, where it can be used to capture the movements of a person or other object. These movements may then be mapped to a computer generated image, as is commonly seen in movies and television shows. This same type of technology has also become common in video games, where the tracking system analyzes the movements of a player's body or a control device to manipulate objects or characters on screen.
Motion tracking can also be useful in following objects in real time. The technology can be used to track objects such as airplanes, missiles, and space debris. One main advantage of this technique is that it can provide high resolution video of whatever object is being tracked, but it does require sufficient light to operate, unlike radar.