与 Gibbs 平滑相结合的 EM 图像重建算法的收敛性。

Convergence of EM image reconstruction algorithms with Gibbs smoothing.

机构信息

Dept. of Biomath., California Univ. Sch. of Med., Los Angeles, CA.

出版信息

IEEE Trans Med Imaging. 1990;9(4):439-46. doi: 10.1109/42.61759.

Abstract

P.J. Green has defined an OSL (one-step late) algorithm that retains the E-step of the EM algorithm (for image reconstruction in emission tomography) but provides an approximate solution to the M-step. Further modifications of the OSL algorithm guarantee convergence to the unique maximum of the log posterior function. Convergence is proved under a specific set of sufficient conditions. Several of these conditions concern the potential function of the Gibb's prior, and a number of candidate potential functions are identified. Generalization of the OSL algorithm to transmission tomography is also considered.

摘要

P.J. Green 定义了一种 OSL（一步延迟）算法，该算法保留了 EM 算法的 E 步（用于发射断层成像中的图像重建），但提供了 M 步的近似解。OSL 算法的进一步修改保证了对数后验函数的唯一最大值的收敛性。在一组特定的充分条件下证明了收敛性。这些条件中有几个涉及吉布斯先验的势函数，并确定了一些候选势函数。还考虑了 OSL 算法在透射断层成像中的推广。