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Glossary of Terms
X64-AN Quad User's Manual
Frame buffer
An area of memory used to hold a frame of image data. A frame buffer may exist on the acquisition
hardware or be allocated by the acquisition hardware device driver in host system memory.
Genlock
When two cameras are genlocked, their internal sync circuits are driven by a common external source.
These cameras output video frames synchronous to each other.
Grab
Acquiring an image frame by means of a frame grabber.
Grayscale
In image processing, the range of available brightness levels, displayed in shades of gray. In an 8-bit
system, the gray scale contains values from 0 to 255.
Host
Refers to the computer system that supports the installed frame grabber.
Interlaced
Describing the standard television method of raster scanning in which the image is the product of two
fields, each of which is made up of the image's alternate lines (i.e., one field is comprised of lines 1, 3,
5, etc., and the other is comprised of lines 2, 4, 6, etc.)
Low Pass Filter
A filter that blocks high frequencies and allows lower frequencies to pass through. Used to limit
undesirable analog information (such as high frequency video noise) before converting to digital data.
NTSC
National Television Systems Committee. Color TV standard used in North America and other
countries. The interlaced video signal is composed of a total of 525 video lines at a frame rate of 30
Hz.
PAL
Phase Alteration by Line. Color TV standard used in most of Europe and other countries. The
interlaced video signal is composed of a total of 625 video lines at a frame rate of 25 Hz.
PCI
Peripheral Component Interconnect. The PCI local bus is a 32-bit high performance expansion bus
intended for interconnecting add-in boards, controllers, and processor/memory systems.
