Retrieval system and method using distance index

摘要

Similarity retrieval is performed through the use of a distance index which contains a concatenated key and pointer information and retains a dictionary type order in the concatenated key. The concatenated key is produced by discretizing the distance from each of a plurality of reference points to an object point representing information to be retrieved in a multidimensional space consisting of a plurality of dimensions corresponding to the plurality of feature parameters and concatenating the resulting discretized distances. The use of the concatenated key allows candidate points in the d-distance neighborhood to be narrowed down.