Table 1 Steps of ring removal algorithm

1. Read corrupted sinogram image.

2. Detect isolated and band rings from first and second level of detection.

3. Classify detected artifacts into Type 1, Type 2, and Type 3.

4. Correct Type 3 artifacts by interpolation.

5. Correct Type 2 artifacts by DC shifting.

6. Correct Type 1 artifacts by exemplar based inpainting.

7. Check for any residual rings in third level detection. If residual ring is detected then go back to step 3. Otherwise exit.