Fast dead zone lattice vector quantisation

A fast method is proposed to determine the quantisation parameters of an entropy constrained lattice vector, called dead zone lattice vector quantisation (DZLVQ). This scheme offers substantial improvement in terms of visual quality with respect to the well-known SPIHT and JPEG2000 algorithms. The tuning of quantisation parameters in variable rate transform coding scheme may involve a critical increasing of the complexity. It is shown that this problem can be solved by a simple iterative procedure using classical LVQ tuning functions. The algorithm ensures a substantial reduction of the complexity while maintaining the compression performance of DZLVQ.