On the amplitude and phase computation of the AM-FM image model

We propose an algorithm to compute modulation functions of the AM-FM image model. We show that previous algorithms suffer from the wrapped orientation problem where the discontinuities in the orientation map of the phase gradient cause undesirable artifacts in the computed modulation functions. We address this wrapped orientation problem by imposing a local smoothness constraint on the phase function and solve for the unwrapped phase. The proposed algorithm produces artifact free modulation functions that are in good agreement with underlying image structure. Finally, we demonstrate the superiority of proposed algorithm with visual examples as well as quantitative measurement.