An embedded still image code algorithm with rate-distortion optimization

An embedded still image coding algorithm with rate-distortion optimization based on human visual weighting is proposed. The rate-distortion optimized embedding code coefficient with decreasing R-D slope, so the first coding bits are ones that have the steepest R-D slope, is used. The distortion can be reduced to the maximum extent per coding bit. The calculation of R-D slope is just a lookup table operation with the help of the probability estimation table of the MQ-adaptive arithmetic coder. The coding speed of the R-D threshold is much faster than the search for the maximum R-D slope. The human visual weighting factor change the order of coding rather than the value of coding. The algorithm has a much faster coding speed and better compression performance.