Unequal Loss Protection of Image Based on Rearranging the Source Symbols
Ya Yang · 2007
It is an efficient system to protect the embedded image data unequally using the interleaver-based structure in order to combat the packet loss in packet erasure channel.In this paper,it is shown that the total number of the decoded source symbols can be increased by rearranging the source symbols within the runs of the same channel code rate in a vertical direction instead of the original horizontal direction,which results in the performance improvement to the original system.The relevant formulas are developed to describe the expected peak signal-to-noise ratio(PSNR)at the receiver based on the rearrangement.By considering the rearrange effect and the minimum quality requirement,a new algorithm based on local search is presented to allocate the transmission bit budget between the source and channel codes.Experiments are carried out with the source coders of SPIHT and JPEG2000 and with the network model of two-state Markov.The results show that the new algorithm can provide significantly higher expected PSNR especially in the cases of small number of packets and large packet length compared to the previous algorithm under the same probability of failure,i.e.,the probability that the quality of the decoded image is below the minimum quality requirement.