@InProceedings{PauRiba2015, author="Pau Riba and Josep Llados and Alicia Fornes and Anjan Dutta", editor="C.-L.Liu and B.Luo and W.G.Kropatsch and J.Cheng", title="Large-scale Graph Indexing using Binary Embeddings of Node Contexts", booktitle="10th IAPR-TC15 Workshop on Graph-based Representations in Pattern Recognition", year="2015", publisher="Springer International Publishing", volume="9069", pages="208--217", optkeywords="Graph matching", optkeywords="Graph indexing", optkeywords="Application in document analysis", optkeywords="Word spotting", optkeywords="Binary embedding", abstract="Graph-based representations are experiencing a growing usage in visual recognition and retrieval due to their representational power in front of classical appearance-based representations in terms of feature vectors. Retrieving a query graph from a large dataset of graphs has the drawback of the high computational complexity required to compare the query and the target graphs. The most important property for a large-scale retrieval is the search time complexity to be sub-linear in the number of database examples. In this paper we propose a fast indexation formalism for graph retrieval. A binary embedding is defined as hashing keys for graph nodes. Given a database of labeled graphs, graph nodes are complemented with vectors of attributes representing their local context. Hence, each attribute counts the length of a walk of order k originated in a vertex with label l. Each attribute vector is converted to a binary code applying a binary-valued hash function. Therefore, graph retrieval is formulated in terms of finding target graphs in the database whose nodes have a small Hamming distance from the query nodes, easily computed with bitwise logical operators. As an application example, we validate the performance of the proposed methods in a handwritten word spotting scenario in images of historical documents.", optnote="DAG; 600.061; 602.006; 600.077", optnote="exported from refbase (http://refbase.cvc.uab.es/show.php?record=2618), last updated on Wed, 16 Jan 2019 09:14:48 +0100", isbn="978-3-319-18223-0", issn="0302-9743", doi="10.1007/978-3-319-18224-7_21", opturl="http://www.springer.com/us/book/9783319182230", file=":http://refbase.cvc.uab.es/files/RLF2015a.pdf:PDF" }