Phase reconstruction of spectrograms with linear unwrapping: application to audio signal restoration

TL;DR

This paper presents a new phase reconstruction method for spectrograms that improves audio signal restoration by ensuring temporal and spectral coherence, outperforming traditional approaches.

Contribution

The paper introduces a linear unwrapping technique for phase reconstruction that effectively captures non-stationary signal features and enhances audio restoration quality.

Findings

Outperforms traditional phase reconstruction methods

Ensures vertical and horizontal coherence in spectrograms

Improves audio restoration results

Abstract

This paper introduces a novel technique for reconstructing the phase of modified spectrograms of audio signals. From the analysis of mixtures of sinusoids we obtain relationships between phases of successive time frames in the Time-Frequency (TF) domain. To obtain similar relationships over frequencies, in particular within onset frames, we study an impulse model. Instantaneous frequencies and attack times are estimated locally to encompass the class of non-stationary signals such as vibratos. These techniques ensure both the vertical coherence of partials (over frequencies) and the horizontal coherence (over time). The method is tested on a variety of data and demonstrates better performance than traditional consistency-based approaches. We also introduce an audio restoration framework and observe that our technique outperforms traditional methods.