DocumentCode :
3016407
Title :
Efficient edge-preserving regularization for limited-angle tomography
Author :
Delaney, Alexander H. ; Bresler, Yoram
Author_Institution :
Coordinated Sci. Lab., Illinois Univ., Urbana, IL, USA
Volume :
3
fYear :
1995
fDate :
23-26 Oct 1995
Firstpage :
176
Abstract :
We demonstrate that the constraint of piecewise smoothness, applied through the use of edge-preserving regularization, can provide excellent tomographic reconstructions from limited-angle data. The tomography problem is formulated as a regularized least-squares optimization problem, and is then solved using a generalization of a recently proposed deterministic relaxation algorithm. This algorithm has been shown to converge under certain conditions when the original cost functional being minimized is convex. We have proven that our more general algorithm is globally convergent under less restrictive conditions, even when the original cost functional is nonconvex. Simulation results demonstrate the effectiveness of the algorithm, and show that for moderate to high photon counts, spectrally weighted error norms perform as well as, or better than a standard error norm that is commonly used for Poisson-distributed data. This suggests that a recently proposed fast Fourier algorithm, which is restricted to using a spectrally weighted error norm, can be used in many practical limited-angle problems to perform the minimization needed by the deterministic relaxation algorithm
Keywords :
computerised tomography; digital simulation; fast Fourier transforms; image reconstruction; least squares approximations; medical image processing; photon counting; smoothing methods; Poisson-distributed data; cost functional; deterministic relaxation algorithm; efficient edge-preserving regularization; fast Fourier algorithm,; limited-angle data; limited-angle problems; limited-angle tomography; minimization; photon counts; piecewise smoothness; regularized least-squares optimization problem; simulation results; spectrally weighted error norm; spectrally weighted error norms; standard error norm; tomographic reconstructions; Application software; Astronomy; Computed tomography; Computer errors; Cost function; Electron microscopy; Energy resolution; Entropy; Image reconstruction; Minimization methods;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Image Processing, 1995. Proceedings., International Conference on
Conference_Location :
Washington, DC
Print_ISBN :
0-8186-7310-9
Type :
conf
DOI :
10.1109/ICIP.1995.537609
Filename :
537609
Link To Document :
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