Video Laboratory

General Description of the Working Principles Measurement Results Authors

Video Laboratory Project

The aim of the Video Laboratory (VL) project was to develop a computer program to process video stream, which detects bright objects, measures their coordinates in time, and enters the measurement results into a database (Microsoft Access). Any well reflected spot of light, with an exact and geometrically correct boundary, that moves within the focal plane of the video camera can be recognized as a spot for detection and measuring coordinates.

The main efforts during the creation of the project were focused on problems of stability. The main difficulties of the video processing are in detecting the center of each spot within a series of spots, and tracing their coordinates on time. In our project they have high level of obstacle protection. The current version of the program can process up to 100 spots (their brightness should be at least 10% over the average back screen brightness), measure and add their coordinates to the database with the frequency of the video camera. Maximum number of spots that can be processed, the accuracy and the speed of their detection all mostly depend on the computer configuration. If we use inexpensive video cameras (CCD black and white cameras) and computers of average power (800 MHz), we can easily measure the coordinates of several moving objects with the frequency of 30 times per second.

The main advantages of this computer program are in its the ability to detect objects moving in the plane (two coordinates), and in the fact that the laboratory devices consist of standard components and do not require detailed assembly.

In "General description of the working principles" part we compare Video Laboratory with the VideoCom (Labold Didactic Company), which is a device for the same aims.

The main components of the program are: computer, standard video camera, light reflectors, reflector lighter and standard devices for the physical laboratory classes.