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.
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.
The following screenshot is taken from the data sheet of the AFE and illus-
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.
Figure 26: Block diagram of AFE (Source: Analog Devices)
