Extraocular image processing for retinal prosthesis based on DSP

Simulations of artificial vision suggest that thousands of electrodes may be required to restore vision for ones with diseases of the outer retina. With the development of MEMS fabrication process for the stimulation electrode array, extraocular image processing is becoming more and more important for the retinal prosthesis systems. A Digital Signal Processor (DSP) based extraocular image processing system (EIPS) for a retinal prosthesis has been developed in this paper. The system mainly consists of a CMOS image sensor and a DSP processing system, which provides the capability of implementing the real-time image processing with low power consumption. Furthermore, this system offers the flexibility of realizing various image processing algorithms with different specification requirements on the DSP by programming, such as different frame rate, resolution and throughput data rate. The related image processing algorithms include the image resizing, color erasing, edge enhancement and edge detection. Finally, the speed of different DSPs in the market has been evaluated and compared for achieving better performance.