RASCor: An associative hardware algorithm for real time stereo

Solving the stereo correspondence problem is an important step towards extraction of three dimensional structure of a scene from two or more images taken from distinct viewpoints. This paper presents a hardware solution to real time stereo matching problem using system of associative relations (SOAR) computational model. SOAR makes use of direction of derivatives for capturing pair-wise pixel interactions and uses pair-wise interactions to determine the underlying structure of associations. Pair-wise pixel interactions are defined over structures called Tokens. The hardware stereo matching solution developed in this study utilizes direction of derivatives to encode inter-pixel associations and implements a real time stereo matching solution. RASCor is realized on an FPGA platform and offers real time stereo matching using hardware parallelism and process pipelining. Real time stereo matching is achieved through hardware unit multiplicity and frequency scaling. The cost of hardware implementation is presented along with performance improvements from frequency scaling, unit multiplicity and search depth for stereo matching.