Graph Matching With a Dual-Step EM Algorithm

—This paper describes a new approach to matching geometric structure in 2D point-sets. The novel feature is to unify the tasks of estimating transformation geometry and identifying point-correspondence matches. Unification is realized by constructing a mixture model over the bipartite graph representing the correspondence match and by affecting optimization using the EM algorithm. According to our EM framework, the probabilities of structural correspondence gate contributions to the expected likelihood function used to estimate maximum likelihood transformation parameters. These gating probabilities measure the consistency of the matched neighborhoods in the graphs. The recovery of transformational geometry and hard correspondence matches are interleaved and are realized by applying coupled update operations to the expected log-likelihood function. In this way, the two processes bootstrap one another. This provides a means of rejecting structural outliers. We evaluate the technique o...

• Type: Journal
• Year: 1998
• Where: PAMI
• Authors: Andrew D. J. Cross, Edwin R. Hancock
• Keywords: 3.5-inch Floppy Discs, Maximum Likelihood Transformation, PAMI 1998, Structural Correspondence Gate