A comparative evaluation of ring artifacts reduction filters for X-ray computed microtomography images

Concentric rings are among the most recurrent artifacts in X-ray computed microtomography imaging. Their presence have a negative impact on the quantitative and qualitative analyses of the data. An interesting approach for ring artifacts removal is based on direct filtering of the reconstructed slices. Slice filtering does not require additional imaging data (i.e. flat fielding images), it does not exclude methods applied during the reconstruction process (i.e. sinogram processing) and it can be applied also to past archived tomographic data. In this work four different approaches for the removal of complete ring artifacts are presented and preliminary compared using a suitably created artificial image as well as an experimental image. After a critical analysis of the considered filters, the results support that an approach based on a modified Sijbers and Postnov [1] method effectively compensates ring artifacts in reconstructed slices, thus resulting in a powerful tool for established microtomography workflows.