Abstract: With the limited computing units on satellites, it generally takes a long time for the on-board embedded processor to process the remote sensing image alignment. The programmable logic gate arrays (FPGAs) can be utilized to accelerate image processing using their internal programmable components. In this paper, we proposed a remote sensing image registration method based on Xilinx's ZYNQ chip accelerated ORB algorithm. It was employed to align the remote sensing images with 3000×3000 pixels, which shortened the time consumption and improved the computational energy efficiency of ORB algorithm. The parallel computing architecture of ORB algorithm with multi-branch single-layer pipeline was realized by using FPGA that can realize a real parallel computing circuit. A combination of hardware and software was used to implement the architecture, which can handle images with different resolutions and can be configured with the number of feature points flexibly. The results show that the accelerated ORB alignment method can provide higher accuracy. Compared with software method, the offset precision loss is less than 0.05 pixel for the OVS-1A remote sensing images and is less than 0.9 pixel for the GF-4 remote sensing images. The time consumption of the ORB algorithm implemented on ZYNQ7020 is reduced by 5750%.

Key words: FPGA；remote sensing image；ORB；parallel computing；embedded system, image registration