Abstract
Low-rankness of amplitude spectrograms has been effectively utilized in audio signal processing methods including non-negative matrix factorization. However, such methods have a fundamental limitation owing to their amplitude-only treatment where the phase of the observed signal is utilized for resynthesizing the estimated signal. In order to address this limitation, we directly treat a complex-valued spectrogram and show a complex-valued spectrogram of a sum of sinusoids can be approximately low-rank by modifying its phase. For evaluating the applicability of the proposed low-rank representation, we further propose a convex prior emphasizing harmonic signals, and it is applied to audio denoising.
Abstract (translated)
在非负矩阵分解等音频信号处理方法中，有效地利用了幅谱图的低粗糙度。然而，这种方法有一个基本的局限性，因为它们只对振幅进行处理，即利用观测信号的相位来重新合成估计信号。为了解决这一局限性，我们直接对复值谱图进行了处理，结果表明，通过改变相位，正弦波的复值谱图可以近似低阶。为了评价所提出的低阶表示的适用性，我们进一步提出了一种突出谐波信号的凸先验，并将其应用于音频去噪。
URL
https://arxiv.org/abs/1903.05603
