Reformulating the binary masking approach of adress as soft masking

Binary masking forms the basis for a number of source separation approaches that have been successfully applied to the problem of de-mixing music sources from a stereo recording. A well-known problem with binary masking is that, when music sources overlap in the time-frequency domain, only one of the overlapping sources can be assigned the energy in a particular time-frequency bin. To overcome this problem, we reformulate the classical pan-pot source separation problem for music sources as a non-negative quadratic program. This reformulation gives rise to an algorithm, called Redress, which extends the popular Adress algorithm. It works by defining an azimuth trajectory for each source based on its spatial position within the stereo field. Redress allows for the allocation of energy in one time-frequency bin to multiple sources. We present results that show that for music recordings Redress improves the SNR, SAR, and SDR in comparison to the Adress algorithm.