Chasing ghosts: characterization of artifact generation in coded aperture decoding due to experimental implementation.

作者：M. Selwood, O. Drury, C. Goyon, P. Campbell, David N. Fittinghoff, A. Link, S. Rocco, P. Volegov, M. Hill · 发表于：Applied Optics · 年份：2025 · DOI：10.1364/ao.558099 · 被引用次数：1 · 研究领域：Medicine

Coded aperture imaging is a form of lensless aperture imaging that projects multiple overlapping images of the source onto the detector, enhancing signal strength, which is advantageous for low-flux sources or high-resolution imaging. This technique requires decoding of the detector signal to reconstruct the original source, which involves convolving the detector data with the aperture pattern. When the signal is from a centered point source, the reconstructed source image is known as the point spread function (PSF). A clean PSF without artifacts is a Dirac delta function [Appl. Opt.20, 1858 (1981)APOPAI0003-693510.1364/AO.20.001858]. This paper examines the robustness of the decoding process against variations in experimental tolerances by analyzing artifact growth in the reconstructed PSF. We illustrate the effects of incorrect magnification, rotation, and detector size and find that aperture-detector rotational misalignment about the imaging axis is the most sensitive parameter, with significant artifact generation occurring with angular offsets of less than one degree. We discuss compensation methods for imperfect aperture placement, finding that small detector sizes produce uncompensatable artifact generation, and compare theoretical predictions with experimental PSF measurements of a rank p19, 6.8 mm thick (less than one mean free path) coded aperture with a 3.5 mm cell size, conducted at the MegaJOuLe Neutron Imaging Radiography dense plasma focus [IEEE Trans. Plasma S...