A Focal Plane Array To Model The Color Processing of the Retina

Abstract

This thesis presents a bio-inspired color camera chip. It is the first focal plane array of photo-pixels that react to temporal color contrast of three different color spectra and thus this vision sensor emulates the color opponencies in the human retina. The array has been designed, implemented and thoroughly characterised in TSMC 90nm CMOS technology. The three different spectra are transduced into photocurrents by stacked photodiodes and temporal changes of the contrast of these three spectra are rep- resented as asynchronous pixels event streams which are read-out off-chip by the Address Event Representation (AER) protocol. The implemented focal plane consists of 16x16 pixels. A single pixel measures 82μm x 82μm and has a fill factor of 27%. The experimental results proved that the designed sensor can discriminate between temporal color contrasts. In comparison to traditional frame-based cameras, the designed vision sensor relaxed the post processing load of a CPU preforming moving objects color recognition.