| 摘要 |
<p>An apparatus for generating a quality-scalable video data stream (36) is described which comprises means (42) for coding a video signal (18) using bl ock-wise transformation to obtain transform blocks (146, 148) of transformat ion coefficient values for a picture (140) of the video signal, a predetermi ned scan order (154, 156, 164, 166) with possible scan positions being defin ed among the transformation coefficient values within the transform blocks s o that in each transform block, for each possible scan position, at least on e of the transformation coefficient values within the respective transform b lock belongs to the respective possible scan position; and means (44) for fo rming, for each of a plurality of quality layers, a video sub-data stream (3 0; 28, 30) containing scan range information indicating a sub-set of the pos sible scan positions, and transform coefficient information on transformatio n coefficient values belonging to the sub-set of possible scan positions suc h that the sub-set of each quality layer comprises at least one possible sca n position not comprised by the sub-set of any other of the plurality of qua lity layers.</p> |
