Embedded multiple description scalar quantizers for progressive image transmission
Robust progressive image transmission over unreliable channels with variable bandwidth requires multiple description coding (MDC) systems that produce highly error-resilient embedded bit-streams. The proposed embedded multiple description scalar quantizers (EMDSQ) meet the desired features consisting of a high redundancy level, fine grain rate adaptation and progressive transmission of each description. Experimental results show that EMDSQ yield better rate-distortion performance in comparison to the multiple description uniform scalar quantizers (MDUSQ) previously proposed in the literature. Moreover, the generalized form of EMDSQ targeting an arbitrary number of channels is proposed, which offers the possibility of designing realistic coders for practical multi-channel communication systems.