High-Performance Optical-Flow Architecture Based on a Multi-Scale, Multi-Orientation Phase-Based Model

The accurate estimation of optical flow is a problem widely experienced in computer vision and researchers in this field are devoting their efforts to formulate reliable and robust algorithms for real life applications. These approaches need to be evaluated, especially in controlled scenarios. Because of their stability phase-based methods have generally been adopted in the various techniques developed to date, although it is still difficult to be sure of their viability in real-time systems due to their high requirements in terms of computational load. We describe here the implementation of a phase-based optical flow in a field-programmable gate array (FPGA) device. The system benefits from phase-information stability as well as sub-pixel accuracy without requiring additional computations and at the same time achieves high-performance computation by taking full advantage of the parallel processing resources of FPGA devices. Furthermore, the architecture extends the implementation to a multi-resolution and multi-orientation implementation, which enhances its accuracy and covers a wide range of detected velocities. Deep pipelined datapath architecture with superscalar computing units at different stages allows real-time processing beyond VGA image resolution. The final circuit is of significant complexity and useful for a wide range of fields requiring portable optical-flow processing engines.