Video-rate pyramid optical flow computation on the linear SIMD array IVIP

The IVIP (IR Video Image Processor) signal processor array is used to process a video sequence to obtain its optical flow. Optical flow is the apparent motion of the intensity patterns in image sequences, and it can be used to obtain information about scene structure and object motion. A differential-based method for optical flow using second-order derivatives is implemented. We investigate both one-level and pyramid implementations. A pyramid implementation makes it possible to estimate much larger image velocities than a one-level implementation. IVIP is a row-parallel bit-serial SIMD processor array. The special ALU design which incorporates a serial-parallel multiplier/divider together with good interprocessor communication makes it very effective for large convolutions. In this paper, we show that we can process 512² image sequences at 50 Hz frame rate for one-level flow and 25 Hz for multi-level pyramid flow