A bit-parallel suffix automaton approach for (δ,γ)-matching in music retrieval

Abstract

(δ,γ)-Matching is a string matching problem with applications to music retrieval. The goal is, given a pattern P1...m and a text T1...n on an alphabet of integers, find the occurrences P' of the pattern in the text such that (i) ∀1 ≤ i ≤ m, |Pi - Pi′ ≤ δ, and (ii) Σ1≤i≤m |Pi - Pi| ≤ γ. Several techniques for (δ,γ)-matching have been proposed. In this paper we show that a classical string matching technique that combines bit-parallelism and suffix automata can be successfully adapted to this problem. This is the first character-skipping algorithm that skips characters using both δ and γ. We implemented our algorithm and drew experimental results on real music showing that our algorithm is superior to current alternatives. © Springer-Verlag Berlin Heidelberg 2003.