Object recognition can be formulated as matching image features to model features. When recognition is exemplar-based, feature
correspondence is one-to-one. However, segmentation errors, articulation, scale difference, and within-class deformation can
yield image and model features which don’t match one-to-one but rather many-to-many. Adopting a graph-based representation
of a set of features, we present a matching algorithm that establishes many-to-many correspondences between the nodes of two
noisy, vertex-labeled weighted graphs. Our approach reduces the problem of many-to-many matching of weighted graphs to that
of many-to-many matching of weighted point sets in a normed vector space. This is accomplished by embedding the initial weighted
graphs into a normed vector space with low distortion using a novel embedding technique based on a spherical encoding of graph
structure. Many-to-many vector correspondences established by the Earth Mover’s Distance framework are mapped back into many-to-many
correspondences between graph nodes. Empirical evaluation of the algorithm on an extensive set of recognition trials, including
a comparison with two competing graph matching approaches, demonstrates both the robustness and efficacy of the overall approach.
Keywords graph matching - graph embedding - Earth Mover’s Distance (EMD) - object recognition