Bidimensional EMD infinite sifting

Calculating mean envelope is defined as an operation (mean envelope operation) in empirical mode decomposition (EMD). According to the filter bank structure of the bidimensional empirical mode decomposition (BEMD), the hypothesis about the mean envelope operation on the band limited two-dimensional signal is brought out. With this hypothesis, the guess of the BEMD infinite sifting is deduced. In the end, the guess is validated primarily with some experiments.