Frame grabber
From Wikipedia, the free encyclopedia
A frame grabber is a component of a computer vision system designed for digitizing analog video signals. It performs the opposite function of a graphics adapter. A typical implementation consists of
- a circuit to recover the horizontal and vertical synchronization pulses from the input signal;
- an analog-to-digital converter;
- a NTSC/SECAM/PAL colour decoder circuit, a function that can also be implemented in software;
- some memory for storing the acquired image (frame buffer);
- a bus interface through which the main processor can control the acquisition and access the data.
Frame grabbers originally had only enough memory to acquire ("grab") and store a single digitized video frame, hence the name. Modern versions can not only acquire longer video sequences, but are also able to compress them in real time using algorithms such as MPEG.
