METHOD, COMPRESSOR, DECOMPRESSOR AND SIGNAL REPRESENTATION FOR LOSSLESS COMPRESSION OF PIXEL BLOCK VALUES USING ROW AND COLUMN SLOPE CODEWORDS

摘要

The invention relates to compression of a pixel block (300) of depth values. A reference codeword (410) is determined as a representation of a reference depth value. A row (420) and a column (430) slope codeword are determined as representations of a basic depth slope for the rows (310) and columns (320) in the block (300), respectively. Representations indicating pixel positions where a slope change occurs along at least a portion of a row (310) or column (320) is determined for at least a subset of the rows (310) or columns (320). A mode codeword (440) is determined as a representation of a set of multiple slope correction patterns. A respect pattern codeword (450) is then selected for rows (310) or columns (320) as identifier of one of the slope correction patterns.