Query by humming via hierarchical filters

This paper proposes an effective implementation of query by humming (QBH) system via hierarchical filters. Firstly locality sensitive hashing (LSH) is used to screen candidate fragments. Secondly linear scaling (LS) is applied to filter out more false candidates and a new method called linear alignment (LA) is presented to locate accurate boundaries of fragments. Then recursive alignment (RA) is employed for the remaining ones. Finally, scores of scaling factor (SF) is fused with scores of RA to rank the songs. Experiments conducted on a database of 5,000 MIDI files show that the proposed approach achieved the relative improvement of mean reciprocal rank up to 37.3% compared with the state-of-the-art method.