Inter- frame feature matching for underwater 3D gated range-intensity correlation imaging

Abstract

Gated range-intensity correlation 3D imaging is a fast high-resolution 3D imaging technology based on range-gated imaging, and has great potential in underwater imaging, marine life detection and topographic mapping. Pixel gray information between different frame-type 2D images is used to obtain 3D image and distance information. However, for moving platforms (such as underwater vehicles), and moving targets (such as zooplankton, fish, etc.), relative motion will cause two frames of images to be misaligned, eventually leading to failure of 3D inversion. To solve the problem, the inter-frame feature matching for underwater 3D gated range-intensity correlation imaging method is proposed. Feature pairs are matched by the bi-directional feature matching, and mean value of the feature-pair coordinate differences is optimized, the method can solve feature point-to-coordinate deviation caused by water body noise, and improve the robustness of feature point matching. Experimental verification on pools and lakes shows that the proposed method is effective and can realize three-dimensional imaging of relative moving targets.