Perceptually motivated restoration of highly degraded audio signals

Abstract. Highly degraded audio restoration presents a live research field currently. However, the recovery of missing, saturated or quantized audio signal information has been studied only marginally in connection to psychoacoustics. The project will provide new models and techniques for audio signal restoration and compression, resulting in significantly improved perceptual quality of the restored audio, compared to the state-of-the-art approaches. The new techniques will be based on convex and non-convex optimization and they will be encompassed by a unifying theoretical framework. The quality of restoration will be evaluated using both the perceptually-motivated objective measures and formal listening tests. The experimental part will answer the question whether simultaneous storage of subsampled and quantized data in both the time and transformed domains can lead to a new strategy of audio coding. Therefore, besides fundamental research, project results should indicate whether the new techniques could be potentially useful in practice in the future.

Goals. The project goal is to develop new models and techniques for audio restoration involving perceptual information, which will lead to a better restoration quality in terms of objective and subjective perceptual quality. Using the new unified framework, an experimental audio codec will be proposed.

Keywords: Signal processing; audio; restoration; sparsity; inpainting; declipping; dequantization; coding; auditory modeling; psychoacoustics; time-frequency representations; filterbanks

• Signal Processing Laboratory, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno
  doc. Mgr. Pavel Rajmic, Ph.D.
  Ing. Pavel Záviška
  Ing. Ondřej Mokrý
  doc. Jiří Schimmel, Ph.D.
  doc. RNDr. Vítězslav Veselý, CSc.

• The Acoustics Research Institute of the Austrian Academy of Sciences, Vienna
  Dr. Nicki Holighaus
  Doz. Dr. Peter Balazs
  Doz. Dr. Bernhard Laback