Annual Report 2010 - Fachgruppe Informatik an der RWTH Aachen ...

Figure 8: Simultaneous mining of dense subgraphs and subspace clusters in attributed graphs
Exploration of Multimedia Databases
Efficient Multimedia Retrieval Based on Earth Mover's Distance
(funded by DFG SE 1039/1-3)
Marc Wichterich, Christian Beecks
For modern information systems, the efficient retrieval of multimedia data and complex
objects is a crucial task for many applications including medical imaging, video analysis,
molecular biology or mechanical engineering. Whereas the mapping of complex objects to
feature vectors has proven its usefulness in many examples, the limitations of the common
Euclidean distance become obvious in case of correlated dimensions in the feature space.
In order to face these problems, the Earth Mover's Distance (EMD) explicitly regards
connections of the components while being based on a ground distance schema. Whereas
algorithms to compute the EMD for pairs of vectors exist, they are too expensive to be
applied to large database of 100,000 or millions of objects. The goal of this research is to
develop new algorithms to efficiently support EMD-based similarity search on very large
databases.
Figure 9: multistep query processing for fast EMD search
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