| 摘要 |
<p>There is disclosed method and apparatus for structured encoding of a previously encoded source (100, 105, 140) of data, where the structure (200, 210, 220, 230) is not defined in the received data. The invention finds particular application in block-based compression of digitised image or audio data derived from analogue sources, for example using MPEG encoding. The encoding introduces discontinuities in pixel colour and/or brightness across the block boundaries (200, 210, 220, 230), the introduction of which can lead to a marked deterioration in quality, and inefficient use of bandwidth. Encoding data using the same block and pixel structure used previously renders the discontinuities effectively invisible, substantially eliminating these problems. To do so, the received data is processed (300) to detect artefacts contained within the previously encoded and decoded data, information as to the structure (200, 210, 220, 230) imposed on the data by the previous encoding process (100, 105, 140) is extracted by analysis of the artefacts, and the received data is encoded by reference to the extracted structure information.</p> |
