Glossary
G-2
ni.com
composite video
A type of color video transmission where synchronization, luma, and
chroma information are transmitted on one analog signal.
contrast
A constant multiplication factor applied to the luma and chroma
components of a color pixel in the color decoding process.
D
DAQ
Data acquisition. (1) Collecting and measuring electrical signals from
sensors, transducers, and test probes or fixtures and inputting them to a
computer for processing. (2) Collecting and measuring the same kinds of
electrical signals with A/D or DIO boards plugged into a computer and
possibly generating control signals with D/A and/or DIO boards in the
same computer.
DMA
Direct memory access. A method by which data can be transferred to
and from computer memory from and to a device or memory on the bus
while the processor does something else; DMA is the fastest method of
transferring data to/from computer memory.
driver
Software that controls a specific hardware device, such as an image
acquisition device.
dynamic range
The ratio of the largest signal level a circuit can handle to the smallest
signal level it can handle (usually taken to be the noise level), normally
expressed in decibels.
E
external trigger
A voltage pulse from an external source that triggers an event, such as
A/D conversion.
