Glossary
GUPPY Technical Manual
V4.0.1
212
AFE
AFE =
a
nalog
f
ront
e
nd
The AFE conditions the analog signal received from the image sensor and
performs the analog-to-digital (A/D) conversion.
AGC
AGC =
a
uto
g
ain
c
ontrol
AGC means that the electronic amplification of the video signal is automat-
ically adjusted to compensate for varying levels of scene illumination.
Aliasing
Phenomenon of interference which occurs when a signal being sampled
contains frequencies that are higher than half the sampling frequency. Typ-
ically can be seen as ragged edges on horizontal lines.
Analog front end
see AFE
AOI
AOI =
a
rea
o
f
i
nterest
see area of interest
Area of interest
Area of interest readout (AOI) refers to a camera function whereby only a
portion of the available pixels are read out from the camera. For example,
it is possible to read out a 10 x 20 pixel rectangular area of pixels from a
camera that has a total resolution of 648 x 488. The result is a much faster
frame rate and less data to be processed. This is also referred to as partial
scan. Various autofunctions (auto shutter, auto gain, auto white balance)
act on the AOI.
Asynchronous shutter
The camera CCD starts to accumulate electrons on receipt of an external
trigger pulse.
Asynchronous
transmission mode
Asynchronous transmission mode is a mode supported by IEEE 1394
(FireWire). IEEE 1394 supports asynchronous data transmission, which
includes receipt datagrams that indicate that the data was transmitted
reliably to the 1394 device. Asynchronous data transfers place emphasis
on delivery rather than timing. The data transmission is guaranteed, and
retries are supported. An example for an asynchronous transmission mode
is the one-shot comand. All cameras receive the one-shot command in the
same IEEE 1394 bus cycle. This creates uncertainty for all cameras in the
range of 125 µs.
AWB
AWB =
a
uto
w
hite
b
alance
A system for automatically setting the white balance in digital cameras.
see white balance
Bayer, Dr. Bryce E.
Dr. Bryce E. Bayer (Eastman Kodak) is the inventor of the so-called BAYER
patent (20 July 1976).