Psychophysics testing of bionic vision image processing algorithms using an FPGA Hatpack

Different image processing approaches are presented that are candidates for the Monash Vision Group prosthetic vision device. As described in a companion paper [6], the Monash Vision Group is developing a bionic eye based on the implantation of 7-11 stimulation tiles on the primary visual cortex of the brain. In the lead up to an expected 2014 first in-human trial of this device, potential image processing techniques and intuitive user interfaces need to be developed and evaluated. An FPGA Hatpack has been developed to give normally sighted people a similar binary limited resolution visual experience expected of a Bionic Eye recipient. The Hatpack has been used to generate new psychophysics results to evaluate and improve the performance and practicality of three different methods of luminance threshold selection. The results show an interesting difference in terms of performance and highlight areas of possible improvement for the algorithms used.