Classification of time-frequency regions in stereo audio

A classification of time-frequency (TF) regions in stereo audio data by the type of mixture the region represents is presented. The detection of the type of mixing is necessary, for example, in stereo-to-multichannel upmixing, audio enhancement, and audio manipulation applications. A generic signal model for a stereo signal is proposed and it is used to derive a method to classify the TF regions into six classes, which are different combinations of central, panned, and uncorrelated sources. An overview of traditional techniques for comparing frequencydomain data is given, and a new approach for classification is proposed, which is based on measures specially trained for the six classes. The performance of the new measures is studied and demonstrated using synthetic and real audio data.