Matrox Electronic Systems II manual Real-time processing, Reference levels, Synchronous function

124 Appendix G: Glossary

■Real-time processing

The processing of an image as quickly as the next image is grabbed.

Also known as live processing.

■Reference levels

The zero and full-scale levels of an analog-to-digital converter. Voltages below a black reference level are converted to a zero pixel value; voltages above a white reference level are converted to the maximum pixel value. Together with the analog gain factor, the reference levels affect the brightness and contrast of the resulting image.

■RGB

A color space that represents color using the primary colors (red, green and blue) as components.

■Synchronous function

A function that does not return control to the caller until it has finished executing.

See also asynchronous function.

■Trigger

A signal that allows image acquisition to be synchronized to external events. If supported, a digitizer can operate in one of two modes upon receiving a trigger:

❐Asynchronous reset mode: If your digitizer supports and uses this mode, the camera is reset to begin a new frame when the trigger signal is received.

❐Next valid frame/field mode: If your digitizer supports and uses this mode, the digitizer will grab the next valid frame or field.

■Vertical sync

The part of a video signal that indicates the end of a frame and the start of a new one.

See also horizontal sync.