Bio-inspired asynchronous pixel event tri-color vision sensor

We have implemented the very first tri-color address event representation (AER) vision sensor. It uses stacked photo diodes for color filtering in a standard STM 90nm CMOS process in a 22×22 pixel array. The AER bus protocol is used to convey asynchronous pixel events inspired by the ganglion cells of a mammalian retina. The pixels employ simple pulse density modulation (PDM) of color filtered light intensity. Asynchronous pixel PDM sensors are known as “octopus” retinae in the community of neuromorphic engineers. We have measured the relative spectra of the available standard PN-junctions and show first experimental results of heuristic color image reconstruction.

[1]  Misha Anne Mahowald,et al.  VLSI analogs of neuronal visual processing: a synthesis of form and function , 1992 .

[2]  Tobi Delbrück,et al.  Self-timed vertacolor dichromatic vision sensor for low power pattern detection , 2008, 2008 IEEE International Symposium on Circuits and Systems.

[3]  Tobi Delbrück,et al.  Event-based color change pixel in standard CMOS , 2010, Proceedings of 2010 IEEE International Symposium on Circuits and Systems.

[4]  Mehdi Azadmehr.  A foveated aer imager chip , 2005 .

[5]  Tobi Delbrück,et al.  A 128$\times$ 128 120 dB 15 $\mu$s Latency Asynchronous Temporal Contrast Vision Sensor , 2008, IEEE Journal of Solid-State Circuits.

[6]  Tobi Delbrück,et al.  A 5 Meps $100 USB2.0 Address-Event Monitor-Sequencer Interface , 2007, 2007 IEEE International Symposium on Circuits and Systems.

[7]  Mehdi Azadmehr,et al.  A foveated AER imager chip [address event representation] , 2005, 2005 IEEE International Symposium on Circuits and Systems.

[8]  Bernabé Linares-Barranco,et al.  A 3.6 $\mu$ s Latency Asynchronous Frame-Free Event-Driven Dynamic-Vision-Sensor , 2011, IEEE Journal of Solid-State Circuits.

[9]  Andreas G. Andreou,et al.  A Contrast Sensitive Silicon Retina with Reciprocal Synapses , 1991, NIPS.

[10]  E. Culurciello,et al.  A biomorphic digital image sensor , 2003, IEEE J. Solid State Circuits.

[11]  Kwabena Boahen,et al.  The Retinomorphic Approach: Pixel-Parallel Adaptive Amplification, Filtering, and Quantization , 1997 .

[12]  Philipp Hafliger.  A spike based learning rule and its implementation in analog hardware , 2000 .