CMOS Active Pixel Sensor for a Polarization-difference Camera
Gregory J. Barlow

Polarization-sensitive vision is well documented as serving in navigation
for many animals, but some types of biological polarization-sensitive
vision may enhance object visibility in scattering media. Because neither
the human eye nor conventional cameras are polarization-sensitive,
artificial polarization vision systems must be designed to exploit the
polarization of light; artificial polarization-difference imaging has been
shown to be capable of enhancing target detection in scattering media.
Previous polarizationsensitive cameras required external processing, were
not real-time, and used relatively large amounts of power. A CMOS active
pixel sensor is presented for use in a low power, portable, real-time
polarization-difference camera. Pixels were designed for integration with
a diffractive optical element polarization analyzer. Column readout
circuits include fixed pattern noise suppression. In addition, a scaling
methodology to enhance system performance and to correct for non-ideal
polarization analyzers is presented.