| 摘要 |
<p>Device for coding digital signals corresponding to images subdivided into blocks, consisting of a first coding channel, of a prediction channel comprising a first inverse quantisation circuit (60), a inverse discrete cosine transform circuit (70), a first adder (85), an image memory (75), a movement compensation stage (80, 90) and a subtractor (100), and of a second coding channel itself particularly comprising a difference calculating circuit (105), a circuit (115) for quantising these differences, and a circuit (125) for coding quantised differences, characterised in that the prediction channel also comprises, between the output of the said circuit for quantising the differences and the said inverse discrete cosine transform circuit, a supplementary branch comprising a second circuit (155) for inverse quantisation of the output signals of the said difference quantisation circuit and a second adder (165) of the outputs of the said first and second inverse quantisation circuits, the output of the said adder being linked to the input of the said inverse discrete cosine transform circuit. Application: coding of images according to two quality levels. <IMAGE></p> |
