Adaptive variable-rate motion vector quantization

A novel block-matching scheme based on adaptive variable-rate motion vector quantizers (AVRMVQs) is presented in this paper. In the scheme, the check points for the block-matching are determined from the codevectors in the AVRMVQs. An on-line training process is employed for the construction of codevectors. The residual error and the frequency of occurrence of the check points are taken into account during the training and block-matching processes. The AVRMVQ scheme outperforms other MVQ schemes which only consider the residual errors and/or do not employ on-line training. Moreover, it has superior rate-distortion performance to the MPEG-4 scheme while having less computational complexity. The AVRMVQ therefore is effective for applications where both low computational complexity and high rate-distortion performance are desired.