Title: Hardware implementation of hexagonal sampling based bio-inspired retinal encoder

Authors: Sharon Vinod; S. Veni

Addresses: Global Business Solutions, IBM India Private Limited, Bangalore 560029, India ' Department of Electronics & Communication Engineering, Amrita Vishwa Vidya Peetham, Amrita Nagar, Coimbatore 641112, Tamil Nadu, India

Abstract: This paper addresses hardware implementation of a power efficient retinal encoder system used in visual prosthesis equipment for blind people. The hardware architecture is inspired from the retinal receptive fields in mammalian vision system. The captured image is passed through several filter banks in different filtering stages in primate vision system. As the photoreceptors in the primate vision system are arranged in hexagonal fashion, the hexagonal tessellation scheme was found to be the most suitable sampling scheme for retinal image processing. In this work, the hardware implementation of different retinal filtering stages and final edge detection scheme is performed in Altera Cyclone II FPGA and in Synopsys Design Vision. An area efficient Cellular Logic Array Processing (CLAP) algorithm is used as the final stage edge detector. Both rectangular and hexagonal edge detection schemes were tested and their performance was analysed using Berkeley Segmentation Dataset and ROC performance scheme.

Keywords: ASIC; application specific integrated circuit; bio-inspired visual prosthesis; cellular logic array processing; FPGA; field programmable gate array; hexagonal image processing; retinal encoder.

DOI: 10.1504/IJSISE.2017.084558

International Journal of Signal and Imaging Systems Engineering, 2017 Vol.10 No.1/2, pp.84 - 94

Received: 23 May 2013
Accepted: 22 May 2014
Published online: 14 Jun 2017 *

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