| 摘要 |
<p>Determining encoding parameters 92 for encoding indexes of a block of indexes 91 used when processing a coding unit in a palette mode. Each index represents a pixel of a coding unit via a palette which associates an index value with a pixel value. A coding unit predictor is obtained from the block of indexes and the palette. The parameters are determined according to the spatial neighbourhood of the pixel and an encoding order. Preferably, one encoding parameter represents the prediction mode, which may be copy left indicating the index is the same as the previous index or copy above indicating the index is the same as the index above. Preferably, the prediction mode is deduced as copy left if the current index is in the top row of indexes or if previous parameters signify a run of indexes in copy above mode. The parameters may be a run-length encoding (RLE) 92 of the indexes and the index level parameter may be chosen from a set of values excluding the value of a particular previous index. The embodiment encodes or decodes images in the HEVC specification. Another independent claim represents pixel values which are not present in the palette as escape values.</p> |
