Statistical optimization of switched two-level quantizers with application to DPCM encoding of color video
Frank H. Hartung, Bernd Girod · 2002
Quantization is the core part of all lossy source coding schemes. We present a design scheme for statistical optimization of a set of one-bit (i.e., two-level) quantizers, given the signal statistics of an arbitrary signal, for example a prediction error signal. The set of quantizers can then be used for block-adaptive quantization of the signal. The quantizer design criterion combines ideas from block truncation coding (BTC) and vector quantization (VQ). As an example application of our design scheme we apply a set of two-level quantizers to adaptive differential pulse code modulation of color video where the quantizers are switched adaptively on a block-by-block basis. Coding results show that this scheme has a better performance than other low-complexity video coding schemes. At 2 bit/pel, it performs more than 2 dB better in peak signal-to-noise ratio than DPCM (differential pulse code modulation) and up to 3.5 dB better than BTC.