On the use of flat-fields for tomographic reconstruction
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- 作者：Clé ; ment Jailin ; Jean-Yves Buffiè ; re ; Franç ; ois Hild ; Martin Poncelet and Sté ; phane Roux
- 关键词：flat-field normalization ; artifact corrections ; computed tomography
- 刊名：Journal of Synchrotron Radiation
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：24
- 期：1
- 页码：220-231
- 全文大小：2597K
- ISSN：1600-5775
文摘
Seeking for quantitative tomographic images, it is of utmost importance to limit reconstruction artifacts. Detector imperfections, inhomogeneity of the incident beam, as classically observed in synchrotron beamlines, and their variations in time are a major cause of reconstruction bias such as `ring artifacts'. The present study aims at proposing a faithful estimate of the incident beam local intensity for each acquired projection during a scan, without revisiting the process of data acquisition itself. Actual flat-fields (acquired without specimen in the beam) and sinogram borders (when the specimen is present), which are not masked during the scan, are exploited to construct a suited instantaneous detector-wide flat-field. The proposed treatment is fast and simple. Its performance is assessed on a real scan acquired at ESRF ID19 beamline. Different criteria are used including residuals, i.e. difference between projections of reconstruction and actual projections. All confirm the benefit of the proposed procedure.