Repozytorium publikacji - Politechnika Gdańska

New signal processing algorithms were introduced to the online service for audio restoration available at the web address: www.youarchive.net. Missing or distorted audio samples are estimated using a specific implementation of the Jannsen interpolation method. The algorithm is based on the autoregressive model (AR) combined with the iterative complementation of signal samples. Since the interpolation algorithm is computationally complex, an implementation which uses parallel computing has been proposed. Many archival and homemade recordings are at the same time clipped and contain wideband noise. To restore those recordings, the algorithm based on the concatenation of signal clipping reduction and spectral expansion was proposed. The clipping reduction algorithm uses interpolation to replace distorted samples with the estimated ones. Next, spectral expansion is performed in order to reduce the overall level of noise. The online service has been extended also with some copyright protection mechanisms. Certain issues related to the audio copyright problem are discussed with regards to low-level music feature vectors embedded as watermarks. Then, algorithmic issues pertaining watermarking techniques are briefly recalled. The architecture of the designed system along with the employed workflow for embedding and extracting the watermark are described. The implementation phase is presented and the experimental results are reported. The chapter is concluded with a presentation of experimental results of application of described algorithmic extensions to the online sound restoration service.

Autorzy

• mgr inż. Janusz Cichowski link otwiera się w nowej karcie ,
• mgr inż. Adam Kupryjanow link otwiera się w nowej karcie ,
• prof. dr hab. inż. Andrzej Czyżewski link otwiera się w nowej karcie