The KLT is a linear transform where the basis functions are taken from the
statistics of the signal, and can thus be adaptive. It is optimal in the
sense of *energy compaction*, i.e it places as much energy as possible
in as few coefficients as possible. The KLT is also called *Principal
Component Analysis*, is also
equivalent with the *Singular Value Decomposition*.
The transform is generally not separable, and thus the full matrix
multiplication must be performed:

where the *U* is the basis for the transform. *U* is estimated from a
number of :

The adaptiveness is not used in the coder, and the basis functions are calculated off-line in MatLab.

Sat Mar 7 16:27:43 PST 1998