CONVERGENCE OF EM IMAGE-RECONSTRUCTION ALGORITHMS WITH GIBBS SMOOTHING
CONVERGENCE OF EM IMAGE-RECONSTRUCTION ALGORITHMS WITH GIBBS SMOOTHING
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DOI：
10.1109/42.61759
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发表时间：
1990-12-01
影响因子：
10.6
通讯作者：
LANGE, K
中科院分区：
文献类型：
--
作者：
LANGE, K
EM发射重建算法的最新修改，包括吉布斯先验承诺更平滑，更吸引人的图像。这些先验包含最近邻相互作用，惩罚相邻像素参数估计的大偏差。在这种情况下，绿色定义了一个OSL（晚一步）算法，它保留了EM算法的E步，但提供了M步的近似解。OSL算法的进一步修改保证了收敛到对数后验函数的唯一最大值。本文证明了收敛的一组特定的充分条件。这些条件中的几个涉及潜在的功能的吉布斯先验，并确定了一些新的，候选人的潜在功能。也被认为是广义的OSL算法的透射层析成像。
Recent modifications of the EM emission reconstruction algorithm to include a Gibbs prior promise smoother, more appealing images. These priors incorporate nearest neighbor interactions that penalize large deviations in parameter estimates for adjacent pixels. In this context, Green has defined an OSL (one step late) algorithm that retains the E-step of the EM algorithm, 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. The present paper proves convergence under a specific set of sufficient conditions. Several of these conditions concern the potential functions of the Gibbs prior, and a number of new, candidate potential functions are identified. Generalization of the OSL algorithm to transmission tomography is also considered.