| 摘要 |
<p>An image encoding and decoding scheme operable according two different modes depending on properties of the processed image is disclosed. In the encoding, an image is decomposed into image blocks (600) comprising image elements (610). The blocks (600) are compressed into block representations (700A, 700B) according to one of two compression modes. A block representation (700A; 700B) comprises two codewords (720A, 730A; 720B, 730B) representing properties of the image elements (610) in the block (600) and a sequence (740A; 740B) of image element associated indices indicative of one of the codewords (720B, 730B) or a property representation generated based on a codeword (730A). The block representation (700A; 700B) also includes a mode index representing the mode, according to which the block representation (700A; 700B) was compressed. This mode index can be provided before, during or after generation of the codewords (720A, 730A; 720B, 730B) and index sequence (740A; 740B). In the decoding, the codewords (720A, 730A; 720B, 730B) and index sequence (740A; 740B) are used to decompress the block representation (700A; 700B) according a decompression mode determined by the mode index (710A; 710B).</p> |
