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EM algorithms for Gaussian mixtures with split-and-merge operation

✍ Scribed by Zhihua Zhang; Chibiao Chen; Jian Sun; Kap Luk Chan


Publisher
Elsevier Science
Year
2003
Tongue
English
Weight
794 KB
Volume
36
Category
Article
ISSN
0031-3203

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✦ Synopsis


In order to alleviate the problem of local convergence of the usual EM algorithm, a split-and-merge operation is introduced into the EM algorithm for Gaussian mixtures. The split-and-merge equations are ÿrst presented theoretically. These equations show that the merge operation is a well-posed problem, whereas the split operation is an ill-posed problem because it is the inverse procedure of the merge. Two methods for solving this ill-posed problem are developed through the singular value decomposition and the Cholesky decomposition. Accordingly, a new modiÿed EM algorithm is constructed. Our experiments demonstrate that this algorithm is e cient for unsupervised color image segmentation.


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