Ring artefact reduction via multi-point piecewise linear flat field correction for X-ray computed tomography

Area of Science:

• Medical Imaging
• Materials Science
• Physics

Background:

• X-ray computed tomography (XCT) is crucial for non-destructive internal structure analysis.
• Ring artifacts in CT images degrade measurement accuracy.
• Inadequate flat field correction is identified as a cause of subtle ring artifacts in high-resolution XCT.

Purpose of the Study:

• To address ring artifacts in high-resolution XCT data.
• To improve the accuracy of CT-based measurements.
• To enhance the signal-to-noise ratio in CT images.

Main Methods:

• Replaced standard two-point flat field correction with a multi-point, piecewise linear approach.
• Applied the proposed correction method to exemplary CT data.
• Evaluated the impact on signal-to-noise ratio and artifact reduction.

Main Results:

• The multi-point flat field correction method effectively reduces ring artifacts.
• An increase in signal-to-noise ratio by up to 12.1% was achieved.
• The study recommends using a minimum of seven open field images for optimal flat field correction.

Conclusions:

• Multi-point, piecewise linear flat field correction is superior to two-point correction for high-resolution XCT.
• The proposed method significantly improves CT image quality and measurement reliability.
• Optimized flat field correction is essential for accurate non-destructive testing using XCT.