Cyclic Sequence Comparison Using Dynamic Warping

Abstract

In this study, we propose a new dynamic warping algorithm for cyclic sequence comparison, which approximate the optimal solution efficiently. The comparison of two sequences, whose starting points are known, is performed by finding the optimal correspondence between their elements, which minimize the distance. If the sequences are cyclic and their starting points are not known, the alignment computation must determine the amount of cyclic shift for the optimal solution. However, this process increases the complexity of the algorithm and may be cumbersome especially for large databases. Instead of finding the optimal solution, the proposed algorithm finds the approximate distance at once and decreases the time complexity substantially. The algorithm is tested in boundary based shape similarity problem. The experiments performed on MPEG-7 Shape database, show that the proposed method performs better than the classical cyclic string comparison methods in the literature and gives very similar results with the optimal solution.