Design of orthogonal and biorthogonal lapped transforms satisfying perception related constraints

We propose a new efficient method for the design of orthogonal and biorthog onal lapped transforms for image coding applications, It is shown how perce ption related constraints such as decay and smoothness of the filters' impu lse responses can be incorporated in the optimization procedure. A decompos ition of lapped transforms (orthogonal and biorthogonal) with 50% overlap l eads to an efficient recursive optimization procedure, which is robust with respect to initial solutions. The importance of this decomposition lies in the fact that it allows to decouple the design of the even-symmetric and t he odd-symmetric filters and hence drastically reduces the number of variab les to be optimized. It furthermore reveals all the variables predetermined by perception related and coding-efficiency related constraints imposed on the filters. We present design and coding examples demonstrating the perce ptual performance and the rate-distortion performance of the resulting tran sforms.