An approach is based on the block discrete cosine transform (DCT). The novelty of this approach is that the transform coefficients of all image blocks are coded and transmitted in absolute magnitude order. The resulting ordered-by-magnitude transmission is accomplished without sacrificing coding efficiency by using partition priority coding. Coding and transmission are adaptive to the characteristics of each individual image. and therefore, very efficient. Another advantage of this approach is its high progression effectiveness. Since the largest transform coefficients that capture the most important characteristics of images are coded and transmitted first, this method is well suited for progressive image transmission. Further compression of the image-data is achieved by multiple distribution entropy coding, a technique based on arithmetic coding. Experiments show that the approach compares favorably with previously reported DCT and subband image codecs.

A new DCT (discrete cosine transform) based coding method for image sequences is presented. This technique utilizes the between frame difference of the DCT coefficients which are coded and transmitted progressively according to their magnitude (large values first). This is achieved without any overhead for the position information of the ordered samples using priority progressive coding (PPC). PPC is a new method that allows the ordered transmission of data sources without any overhead for the position information. Experiments were performed to test this method. The results from these experiments show improvement over previously reported DCT based methods.>