Reversible transform for lossy and lossless 2-D data compression

    公开(公告)号:EP1672517B1

    公开(公告)日:2018-08-29

    申请号:EP05025154.5

    申请日:2005-11-17

    摘要: A 2D transform and its inverse have an implementation as a sequence of lifting steps arranged for reduced computational complexity (i.e., reducing a number of non-trivial operations). This transform pair has energy compaction properties similar to the discrete cosine transform (DCT), and is also lossless and scale-free. As compared to a separable DCT transform implemented as 1D DCT transforms applied separably to rows and columns of a 2D data block, the transforms operations are re-arranged into a cascade of elementary transforms, including the 2x2 Hadamard transform, and 2x2 transforms incorporating lifting rotations. These elementary transforms have implementations as a sequence of lifting operations.