Evaluation of Soft Information based JPEG2000 Decoders

Error free transmission is not always possible in todays nor future's communication networks without making retransmissions. Retransmissions, however, introduce delay. To delay sensitive applications the concept of soft information, i.e. lower layer knowledge about the channel conditions, could reduce the number of retransmissions. This paper explores the utilization of soft information in image decoding. It is not sufficient to treat the soft information and the image decoder separately. By combining soft information and error resilience in the decoder the image quality can be improved. Two modified JPEG2000 image decoders that utilize soft information have been developed. Experiment results with images transmitted over a simulated wireless channel show that a simple decoding process which utilizes soft information can give high gains in image quality. Only marginally higher gains are observed with a more complex decoding process