UDC 004.932
MODIFIED METHOD FOR REAL-TIME COMPUTING DENSE OPTICAL FLOW ON FPGA
A. V. Bratulin, post-graduate student, RSREU, Ryazan, Russia;
orcid.org/0000-0003-3745-296X, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
M. B. Nikiforov, Ph.D. (Tech.), associate professor, RSREU, Ryazan, Russia;
orcid.org/0000-0002-4796-0776, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
A. I. Efimov, Ph.D. (Tech.), associate professor, RSREU, Ryazan, Russia;
orcid.org/0000-0002-4014-8718, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
One of the important problems in the field of vision systems is the problem of implementing the functions of detection and selection of moving objects on the video image of high definition in real time. These functions are implemented using the concept of optical flow. The article deals with the method of hardware calculation of dense optical flow in the rate of arrival of pixels on the basis of correlation-extreme algorithm on high-definition video image. The aim of the work is to develop a modified version of the method for calculating the dense optical flow based on the correlation-extreme algorithm in real time on a high-definition video image. This modified version of the method should have no less performance than the original, but it takes less hardware costs. A more optimal variant of the device of the unit for calculating the sums of absolute differences for each installation point of the standard window is proposed. This version contains a smaller internal memory size and fewer shift registers. The principle of parallelization and pipelining, which allows to minimize the amount of calculations, is considered in detail. Hardware costs are analyzed when implementing the method on XILINX zynq Ultra Scale + FPGA from the MPSoC zcu102 Evaluation Kit debug Board.
Key words: optical flow, FPGA, video, pixel, correlation algorithm, criterion function, pattern, search zone, pattern window, absolute difference, pipeline, SAD, shift register.