PositIV:A Configurable Posit Processor Architecture for Image and Video Processing

Image processing is essential for applications such as robot vision, remote sensing, computational photography, augmented reality etc. In the design of dedicated hardware for such applications, IEEE Std 754™ floating point (float) arithmetic units have been widely used. While float-based architectures have achieved favorable results, their hardware is complicated and requires a large silicon footprint. In this paper we propose a Posit-based Image and Video processor (PositIV), a completely pipelined, configurable, image processor using posit arithmetic that guarantees lower power use and smaller silicon footprint than floats. PositIV is able to effectively overlap computation with memory access and supports multidimensional addressing, virtual border handling, prefetching and buffering. It is successfully able to integrate configurability, flexibility, and ease of development with real-time performance characteristics. The performance of PositIV is validated on several image processing algorithms for different configurations and compared against state-of-the-art implementations. Additionally, we empirically demonstrate the superiority of posits in processing images for several conventional algorithms, achieving at least 35–40% improvement in image quality over standard floats.