Verfahren zur Kodierung und Übertragung von digitalen Bildern einer Bildsequenz mit mindestens zwei Qualitätsniveaus und zugehörige Geräte

摘要

The field of the invention is that of the transmission of digital images able, on the one hand, to be received by mobiles, in particular under difficult conditions of reception, and on the other hand by fixed receivers, demanding high image quality. <??>The invention relates to a method of coding and transmitting digital images, with at least two quality levels, each digital image consisting of at least one matrix of coded image elements, comprising a partitioning (11) of each of the said images (10) into blocks (12) of image elements, a reversible mathematical transformation (21) applied to each of the said blocks (12) of image elements, a quantising (23) of the coefficients (22) of the transformed image blocks and a coding (25) of the quantised coefficients, the said transformed coefficients being distributed into at least two digital trains (b1, b2), the first digital train (b1) comprising basis coefficients making it possible to reconstruct an image of standard quality, and at least one second digital train (b2) comprising a set of complementary coefficients, making it possible to reconstruct, in combination with the said basis coefficients of the first digital train (b1), and possibly the coefficients of the other complementary digital trains, images of higher quality, the said digital trains (b1, b2) being processed and/or used in distinct manner, upon coding. <IMAGE>