基于变分的 CT 图像环形伪影校正

Effective removal of ring artifacts in CT images is an important research area in the field of medical image processing. The existing methods have some difficulties and challenges in preserving the edges and details of CT images while removing ring artifacts. In this paper, we model the removal of ring artifacts as a problem of energy minimization based on the idea of variational optimization and propose a post-processing method to alleviate the conflict between maintaining image information and removing artifacts. The variational model has been constructed according to the analysis of the mechanism and characteristics of ring artifacts. On the one hand, we design a more suitable gradient fidelity term based on the geometrical characteristics of ring artifacts to enhance the protection on image details. On the other hand, we construct a relative total variational regular term with the ability of artifact identification based on the edge characteristics of ring artifacts, so as to reduce influences on the structural information of images. The designed variational model is to be solved by an efficient optimization algorithm to effectively remove ring artifacts. Experimental results show that the proposed method presents better performance on both visual inspection and quantitative assessment.