Shengkun Yao | Search arXiv

arXiv2026

A Unified Frequency-Domain Model for Cascaded Filter-Interpolation Modulation in Tomographic Reconstruction

The fidelity of image reconstruction from projections in linear inverse problems, such as tomography, is critically dependent on the synergistic interaction between frequency-domain filtering and spatial-domain interpolation. However, a physical model that can quantitatively describe how these two components cascade interact in the frequency domain and ultimately determine image quality is still lacking to this day. Here, we introduce a unified frequency-domain model that conceptualizes the combined effect of filtering and interpolation in the filtered backprojection (FBP) algorithm as a cascaded modulation process. This model demonstrates that the effective reconstruction spectrum is determined by the original projection data being sequentially modulated by the frequency responses of the filter and the interpolation kernel. Comprehensive numerical simulations and synchrotron radiation CT experiments validate the model, confirming its power to explain the performance hierarchy of classical filter-interpolation pairs under both ideal and noisy conditions. The model successfully predicts key performance characteristics, including spatial resolution and structural fidelity, thereby elucidating the physical principles behind the efficacy of specific combinations. This work establishes a generalizable theoretical foundation for analyzing cascaded systems in linear inverse problems, moving the practice of algorithm selection in computational imaging from empiricism to a principled, physics-based paradigm.

eess.IV↗

arXiv2025

Ring artifacts correction method in x-ray computed tomography based on stripe classification and removal in sinogram images

X-ray computed tomography (CT) is widely utilized in the medical, industrial, and other fields to nondestructively generate three-dimensional structural images of objects. However, CT images are often affected by various artifacts, with ring artifacts being a common occurrence that significantly compromises image quality and subsequent structural interpretation. In this study, a ring artifact correction method based on stripe classification and removal in sinogram images was proposed. The proposed method classifies ring artifacts into single stripes and multiple stripes, which were identified and eliminated using median filtering and multiphase decomposition, respectively. A novel algorithm combining median filtering, polyphase decomposition and median filtering was further developed to eliminate all forms of stripes simultaneously and effectively. The efficacy of the proposed method was validated through both simulated and experimental CT data. The study provides a novel perspective and integrated approach to addressing ring artifacts in X-ray CT. It will be of significant illuminating to a diverse readership, including radiologists, clinical researchers, and industrial scientists.

physics.med-ph↗