ERROR RESILIENT STILL IMAGE PACKETIZATION METHOD AND PACKET STRUCTURE

摘要

A packetization method and packet structure improve the robustness of a bitstream generated when a still image is decomposed with a wavelet transform. The wavelet coefficients of one "texture unit" are scanned and coded in accordance with a chosen scanning method to produce a bitstream. The bitstreams for an integral number of texture units are assembled into a packet, each of which includes a packet header. Each packet header includes a resynchronization marker to enable a decoder to resynchronize with the bitstream if synchronization is lost, and an index number which absolutely identifies one of the texture units in the packet to enable a decoder to associate following packets with their correct position in the wavelet transfer domain. The domain information enables a channel error to be localized to a particular packet, preventing the effects of the error from propagating beyond packet boundaries. The invention is applicable to the pending MPEG-4 and JPEG-2000 image compression standards.