Removing Ring Artifacts in CBCT Images Using Smoothing Based on Relative Total Variation

Removing ring artifacts in Cone Beam Computed Tomography (CBCT) images without impairing the image quality is critical for the application of CBCT. In this paper, we propose a novel method for the removal of ring artifacts in CBCT Images using an image smoothing based on relative total variation (RTV). After transforming the CBCT image into polar coordinates, we introduce a single-direction smoothing to separate the small scale textures, which include the artifacts, from the image structures. Then the artifact template is generated by median value extraction. Finally, the artifact template is transformed back into Cartesian coordinates and is subtracted from the original CBCT image. Experiments on different CBCT images show that the proposed method can obtain satisfactory results.