ID | 116149 |
タイトル別表記 | 拡張指数型測度族の最小化に基づき導出された雑音に頑健な画像再構成
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著者 |
山口, 雄作
Shikoku Medical Center for Children and Adults
アボウ アルオラ, オマル
Tanta University
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キーワード | power-divergence measure
computed tomography
iterative reconstruction
maximum-likelihood expectation-maximization method
continuous-time image reconstruction
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資料タイプ |
学位論文
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抄録 | The problem of tomographic image reconstruction can be reduced to an optimization problem of finding unknown pixel values subject to minimizing the difference between the measured and forward projections. Iterative image reconstruction algorithms provide significant improvements over transform methods in computed tomography. In this paper, we present an extended class of power-divergence measures (PDMs), which includes a large set of distance and relative entropy measures, and propose an iterative reconstruction algorithm based on the extended PDM (EPDM) as an objective function for the optimization strategy. For this purpose, we introduce a system of nonlinear differential equations whose Lyapunov function is equivalent to the EPDM. Then, we derive an iterative formula by multiplicative discretization of the continuous-time system. Since the parameterized EPDM family includes the Kullback–Leibler divergence, the resulting iterative algorithm is a natural extension of the maximum-likelihood expectation-maximization (MLEM) method. We conducted image reconstruction experiments using noisy projection data and found that the proposed algorithm outperformed MLEM and could reconstruct high-quality images that were robust to measured noise by properly selecting parameters.
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掲載誌名 |
Entropy
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ISSN | 10994300
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出版者 | MDPI
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巻 | 23
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号 | 8
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開始ページ | 1005
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発行日 | 2021-07-31
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備考 | 内容要旨・審査要旨・論文本文の公開
本論文は,著者Ryosuke Kasaiの学位論文として提出され,学位審査・授与の対象となっている。 |
権利情報 | This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
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言語 |
eng
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著者版フラグ |
博士論文全文を含む
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文科省報告番号 | 甲第3606号
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学位記番号 | 甲保第54号
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学位授与年月日 | 2022-03-23
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学位名 |
博士(保健学)
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学位授与機関 |
徳島大学
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部局 |
医学系
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