Allied International V2.4.0 Benutzerhandbuch
Description of the data path
OSCAR Technical Manual V2.4.0
59
White balance
Oscar cameras have both manual and automatic white balance.
White balance is applied so that non-colored image parts are displayed non-
colored.
colored.
White balance does not use the so called PxGA® (Pixel Gain Amplifier) of the
analog front end (AFE) but a digital representation in the FPGA in order to
modify the gain of the two channels with lower output by +9.5 dB (in 512
steps) relative to the channel with highest output.
analog front end (AFE) but a digital representation in the FPGA in order to
modify the gain of the two channels with lower output by +9.5 dB (in 512
steps) relative to the channel with highest output.
The following screenshot is taken from the data sheet of the AFE and illus-
trates the details:
trates the details:
The analog color signal, coming in pulse amplitude modulation from the sen-
sor is in the form of the BAYER™ color pattern sequence. It is initially pro-
cessed in the CDS (correlated double sampler) and then bypasses the PxGA
before further amplification and digitization.
sor is in the form of the BAYER™ color pattern sequence. It is initially pro-
cessed in the CDS (correlated double sampler) and then bypasses the PxGA
before further amplification and digitization.
Figure 26: Block diagram of AFE (Source: Analog Devices)