NMF-based multiple pitch estimation using sparseness and inter-frame continuity constraints
This paper proposes NMF-based (non-negative matrix factorization) multiple pitch estimation algorithm. The approach of NMF-based multiple pitch estimation is to decompose input magnitude spectrogram into sum of basis spectra representing individual pitches. In decomposing music signals, the amplitude of basis spectra should have sparseness, and the shape of amplitude should be continuous between neighbor temporal frames. We introduce the constraint using matrix norm to enforce these characteristic at once and propose new NMF algorithm for spectral decomposition with this constraint. The evaluation of solo piano music shows this algorithm can implement more robust pitch estimation in the place which input spectrum has certain different shape from basis spectra or the shape of input spectrum has temporal change.