用于图像重建和传感器场估计的最大熵期望最大化算法。
Maximum-entropy expectation-maximization algorithm for image reconstruction and sensor field estimation.
作者信息
Hong Hunsop, Schonfeld Dan
机构信息
Multimedia Communications Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607-7053, USA.
出版信息
IEEE Trans Image Process. 2008 Jun;17(6):897-907. doi: 10.1109/TIP.2008.921996.
In this paper, we propose a maximum-entropy expectation-maximization (MEEM) algorithm. We use the proposed algorithm for density estimation. The maximum-entropy constraint is imposed for smoothness of the estimated density function. The derivation of the MEEM algorithm requires determination of the covariance matrix in the framework of the maximum-entropy likelihood function, which is difficult to solve analytically. We, therefore, derive the MEEM algorithm by optimizing a lower-bound of the maximum-entropy likelihood function. We note that the classical expectation-maximization (EM) algorithm has been employed previously for 2-D density estimation. We propose to extend the use of the classical EM algorithm for image recovery from randomly sampled data and sensor field estimation from randomly scattered sensor networks. We further propose to use our approach in density estimation, image recovery and sensor field estimation. Computer simulation experiments are used to demonstrate the superior performance of the proposed MEEM algorithm in comparison to existing methods.
在本文中,我们提出了一种最大熵期望最大化(MEEM)算法。我们将所提出的算法用于密度估计。为使估计的密度函数具有平滑性而施加了最大熵约束。MEEM算法的推导需要在最大熵似然函数的框架内确定协方差矩阵,而这很难通过解析方法求解。因此,我们通过优化最大熵似然函数的一个下界来推导MEEM算法。我们注意到,经典的期望最大化(EM)算法此前已用于二维密度估计。我们建议将经典EM算法的应用扩展到从随机采样数据进行图像恢复以及从随机散布的传感器网络进行传感器场估计。我们还建议在密度估计、图像恢复和传感器场估计中使用我们的方法。通过计算机模拟实验来证明所提出的MEEM算法相较于现有方法具有优越的性能。