Clustering of Video Objects by Graph Matching

We propose a new graph-based data structure, called spatio temporal region graph (STRG) which can represent the content of video sequence. Unlike existing ones which consider mainly spatial information in the frame level of video, the proposed STRG is able to formulate its temporal information in the video level additionally. After an STRG is constructed from a given video sequence, it is decomposed into its subgraphs called object graphs (OGs), which represent the temporal characteristics of video objects. For unsupervised learning, we cluster similar OGs into a group, in which we need to match two OGs. For this graph matching, we introduce a new distance measure, called extended graph edit distance (EGED), which can handle the temporal characteristics of OGs. For actual clustering, we exploit expectation maximization (EM) with EGED. The experiments have been conducted on real video streams, and their results show the effectiveness and robustness of the proposed schemes

[1]  Vamsi K. Srikantam,et al.  On mixture density and maximum likelihood power estimation via expectation-maximization , 2000, ASP-DAC '00.

[2]  Amir Averbuch,et al.  Tracking of moving objects based on graph edges similarity , 2003, 2003 International Conference on Multimedia and Expo. ICME '03. Proceedings (Cat. No.03TH8698).

[3]  Mario Vento,et al.  Graph matching applications in pattern recognition and image processing , 2003, Proceedings 2003 International Conference on Image Processing (Cat. No.03CH37429).

[4]  Horst Bunke,et al.  A graph distance metric based on the maximal common subgraph , 1998, Pattern Recognit. Lett..

[5]  Hwann-Tzong Chen,et al.  Multi-object tracking using dynamical graph matching , 2001, Proceedings of the 2001 IEEE Computer Society Conference on Computer Vision and Pattern Recognition. CVPR 2001.

[6]  Michael R. Lyu,et al.  Video summarization by spatial-temporal graph optimization , 2004, 2004 IEEE International Symposium on Circuits and Systems (IEEE Cat. No.04CH37512).

[7]  G. Levi.  A note on the derivation of maximal common subgraphs of two directed or undirected graphs , 1973 .