A Resource-Efficient Pipelined Architecture for Real-Time Semi-Global Stereo Matching

Abstract

It is still a grand challenge to implement a high-accuracy and high-performance stereo matching algorithm on a resource-limited hardware platform in stereo vision systems. This paper proposes a resource-efficient pipelined hardware architecture with four-cycle time-sharing for the semi-global matching (SGM) algorithm with weighted path cost aggregation. To save hardware resources, we also combined image down-sampling and disparity skipping in the SGM algorithm. The presented architecture is synthesized and implemented on a Zynq-7 FPGA board, which results in a throughput of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1280 \times 960/62.5}$ </tex-math></inline-formula> fps with 75 disparity levels at the maximum frequency of 216 MHz. To improve the accuracy of the disparity map at close range, we also adapt the presented architecture with two-cycle time-sharing, and the disparity range is increased to 128, which attains the processing of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${1280 \times 960/116}$ </tex-math></inline-formula> fps at 200 MHz on VCU-118 FPGA board; the throughput reaches 18245 MDE/s. The result shows that the whole architecture only takes 50465 LUTs, 48046 Registers, 125.5 BRAMs with 128 disparity levels, which is much more efficient than the latest reference work.