Abstract: Objective Ring artifacts often appear in flat-panel detector-based CT images due to the malfunction or
mis-calibration of the detector elements that result in stripe artifacts in the line integral projection (sinogram) data. The ring
artifacts lower the image quality and affect image-based diagnoses. Here we propose a ring artifacts removal approach based
on wavelet filtering in the sinogram domain. The line integral projection (sinogram) dataset were divided into 4 sub-sinogram
dataset, and for each of them the wavelet decomposition operation was employed to produce the associated wavelet dataset,
followed by filtering operation on the vertical detail band and the low-pass detail band. Wavelet reconstruction operation was
then performed, and the weighted moving average filter was used to yield the filtered sinogram, which was processed using
filtered back-projection (FBP) for image reconstruction. The results showed that the proposed approach could effectively
remove the ring artifacts while preserving the structural information of the image.