National Instruments NI-IMAQ User Manual
Glossary
© National Instruments Corporation
G-3
driver
Software that controls a specific hardware device, such as an IMAQ or
DAQ device.
DAQ device.
E
external trigger
A voltage pulse from an external source that triggers an event such as
A/D conversion.
A/D conversion.
F
field
For an interlaced video signal, a field is half the number of horizontal lines
needed to represent a frame of video. The first field of a frame contains all
the odd-numbered lines, the second field contains all of the even-numbered
lines.
needed to represent a frame of video. The first field of a frame contains all
the odd-numbered lines, the second field contains all of the even-numbered
lines.
frame
A complete image. In interlaced formats, a frame is composed of two fields.
function
A set of software instructions executed by a single line of code that may
have input and/or output parameters and returns a value when executed.
have input and/or output parameters and returns a value when executed.
G
gamma
The nonlinear change in the difference between the video signal’s
brightness level and the voltage level needed to produce that brightness.
brightness level and the voltage level needed to produce that brightness.
GUI
Graphical user interface. An intuitive, easy-to-use means of
communicating information to and from a computer program by means
of graphical screen displays. GUIs can resemble the front panels of
instruments or other objects associated with a computer program.
communicating information to and from a computer program by means
of graphical screen displays. GUIs can resemble the front panels of
instruments or other objects associated with a computer program.
H
hardware
The physical components of a computer system, such as the circuit boards,
plug-in boards, chassis, enclosures, peripherals, and cables.
plug-in boards, chassis, enclosures, peripherals, and cables.
hue
Represents the dominant color of a pixel. The hue function is a continuous
function that covers all the possible colors generated using the R, G, and B
color spectrum. See also RGB.
function that covers all the possible colors generated using the R, G, and B
color spectrum. See also RGB.
Hz
Hertz. Frequency in units of 1/second.