A method is disclosed for decomposing a set of even and odd pictures into low-band and high-band pictures respectively in a image decomposing unit, in which the even picture is used by at least two prediction motion compensators on which the output signal of each prediction motion compensator is scaled according to the number of prediction motion compensators. The method includes calculating the high-band picture by subtracting from the odd picture the scaled motion-compensated signals and using the high-band picture in the at least two update motion compensators, the output signal of each update motion compensator being scaled according to the number of update motion compensators. Finally, the low-band picture is calculated by adding the scaled update motion-compensated signals to the even picture.