A Heuristic Bitrate Control for Non-embedded Wavelet Image Encoders

Most recently developed wavelet image emcoders support as native feature an embedded bitrate control that could be useful for applications where obtaining an accurate bitrate is critical. Well-known encoders like JPEG2000 and SPIHT employ embedded coding. However, this feature makes them highly complex, being a serious restriction for certain applications and devices (such as mobile multimedia communications involving PDAs, mobile phones, etc.). As a consequence, in the last years, authors proposed non-embedded encoders with vetyfast and low-memory-demanding encoding/decoding processes. In this paper, we propose rate control tools that are able to supply the required rate control accuracy with as low as possible complexity increase. Experimental tests show that good results are obtained by employing trivial models of the encoder engine, being able to modulate the accuracy degree with lightweight iterative versions