Threshold-Dependent Joint Bilateral Filter Algorithm for Enhancing 3D Gated Range-Intensity Correlation Imaging

摘要

Three-dimensional gated range-intensity correlation imaging (GRICI) can acquire three-dimensional information of targets with high range resolution in real time. In practical applications, the intensity distribution of laser illumination, light propagation property and target optical reflectivity lead to data holes for 3D images. In this paper, we proposed an improved threshold-dependent joint bilateral filter (TJBF) algorithm based on the characteristics of 3D GRICI to fill data holes and reduce noise. In our method, the composite intensity image obtained by adding two overlapped gate images is used as the gray-domain guidance image for the joint bilateral filter of 3D images. The threshold of 3D reconstruction is used to determine the pixels to be filled and the calculation weight to ensure the accuracy of filling holes and denoising. Experiments show that the holes of 3D images are effectively filled, the whole 3D image is smooth and target edges are clear, and the range resolution is improved after repaired. The research is beneficial for enhancing 3D GRICI in applications of underwater imaging and 3D measurement.