VDM Mahapakulchai, S: Image Transmission Systems for Wireless Ch

In the modern day, many novel information technologies involve the transmission of imagery over noisy channels such as satellite and wireless mobile channels. In general, a low-bit-rate image transmission system requires an outstanding image encoder that provides both an excellent quality for the reconstructed image and a high compression ratio. However, the resulting compressed bit stream becomes highly sensitive to channel noise. There have been several approaches to add error resiliency to an image coder. For instance, the joint source-channel technique (JSC) techniques are developed by considering both source and channel codecs. This book is focused on a kind of this technique known as source-controlled channel decoding. In particular, the residual redundancy in MPEG-4 compressed imagery is considered. Here an embedded zerotree wavelet (EZW) algorithm is used to generate a compressed bit stream, which is then passed through a ring convolutional encoder (CE) and a CPFSK modulation system. Moreover, the design of trellis codes using ring convolutional codes and CPFSK for MAP decoding is also described.