A study on the optimal attributes of transform domain vector quantization for image and video compression

The concept of vector transform coding (VTC) is examined. It is noted that the optimal transform for the purpose of vector quantization should reduce the correlation between the transform domain vectors and preserve the correlation among the components within each vector. An intrinsic coupling factor is defined to quantitatively measure how closely the components are coupled within a vector, and a bit-allocation mechanism is derived to assign bits to the transform domain vectors. Following the guidance of such a general study, a new scheme is proposed for image and video compression. Simulation results show excellent subjective quality at a bit-rate of 3.3 Mb/s