Glossary
NI-IMAQfor IEEE-1394 Cameras User Manual G-6 ni.com
O
operating system Base-levelsoftware that controls a computer, runs programs, interacts with
users,and communicates with installed hardware or peripheral devices.
P
PCI Peripheral Component Interconnect. A high-performance expansion bus
architecture originallydeveloped by Intel to replace ISA and EISA. PCI
offersa theoretical maximum transfer rate of 132 Mbytes/s.
picture aspect ratio The ratio of the activepixel region to the active line region. For standard
video signals likeRS-17 0o rCCIR, the full -sizepict ure aspect ratio
normally is 4/3(1.33).
pixel Pictureelement. The smallest division that makes up the video scan line.
Fordisplay on a computer monitor, a pixel’s optimum dimension is square
(aspect ratio of 1:1, or the width equal to the height).
pixelaspect ratio The ratio between the physical horizontal size and the vertical size of the
regioncovered by the pixel. An acquired pixel should optimally be square,
thus the optimal valueis 1.0, but typically it falls between 0.9 5 and 1.05,
depending on camera quality.
protocol The exactsequence of bits, characters, and control codes usedto transfer
data between computers and peripherals through a communications
channel.
pts Points.
R
RAM Random-accessm emory.
realtime Aproperty of an event or system in which data is processed as it is acquired
insteadof being accumulated and processed at a later time.