Distortion-optimized transmission of multiple description coded images over noisy channels with feedback
Transmission of compressed images over noisy channels is challenging because the encoded bitstreams are sensitive to channel errors. Multiple description coding (MDC) schemes encode a given image into multiple independent descriptions and then transmit them over separate channels; this way, packet loss in one (or some) channel(s) can be compensated by the received packets in other channels. However, image content can not be recovered when all descriptions are lost simultaneously. Instead of using error correction codes, we propose to transmit MDC descriptions over communication channels with feedback. The NACK-only, SR-ARQ scheme is applied as the transport protocol. Upon receiving a NACK, the sender follows the proposed optimal transmission strategy to select the next packet to transmit such that the end-to-end distortion of the received image is minimized.