Review of the influence of noise in X-ray computed tomography measurement uncertainty

Abstract

Different aspects of noise in X-ray computed tomography (XCT) for industrial purposes are examined. An overview of the most common noise metrics is given, together with a description of XCT noise influence quantities. We address the current state of the art in understanding the contribution of noise to XCT measurement uncertainty, giving a chronological view of the different attempts that have been made to account for the contribution from noise to XCT measurement uncertainty. We conclude that approaches to estimating the contribution of noise to XCT measurement uncertainty that account for not only noise, but also other factors that affect image quality (e.g., scattering, beam hardening and blurring) are preferable to approaches that only account for noise.

On Acquisition Parameters and Processing Techniques for Interparticle Contact Detection in Granular Packings Using Synchrotron Computed Tomography

“…Contrast-to-noise ratio (CNR) and normalised Shannon entropy (NSE) are conventional image quality metrics [ 60 , 61 ]. The CNR is defined as: where and are the mean grey values of the foreground and background, respectively, and σ b is the standard deviation of the background.…”

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“…The CR allows distinguishing several structures due to their singularity in the grayscale. The noise, caused by the attenuation coefficient variation between voxels [26,27], is related to the amount of signal received by the detector (a high-intensity signal generates an image with a low noise level and high CR). Considering that the contrast-to-noise ratio (CNR) is measurable and improvable, the CNR was used to evaluate the quality of the tomographic image performed [28].…”

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