A 2D-wavelet packet basis is described by a quad-tree and a signal (or a pair
of signals in case of a biorthogonal basis). 
For more details see \cite{mallat:wavelet}. In MegaWave2, a
quad-tree is described by a \verb+Cimage+. This function permits to perform
simple manipulations on quad-trees.

Notice the same \verb+Cimage+ can be used for the input and output tree.

A precise description of the tree representation can be
found in the documentation of the module \verb+wp2dmktree+.

You can find examples in modules \verb+wp2doperate+ and \verb+wp2dchangepack+.

