Modifying Signals in Transform Domain: a Frame-Based Inverse Problem
Within this paper a method for morphing audio signals is presented. The theory is based on general frames and the modification of the signals is done via frame multiplier. Searching this frame multiplier with given input and output signal, an inverse problem occurs and a priori information is added with regularization terms. A closed-form solution is obtained by a diagonal approximation, i.e. using only the diagonal entries in the signal transformations. The proposed solutions for different regularization terms are applied to Gabor frames and to the constant-Q transform, based on non-stationary Gabor frames.