Reversible transform for lossless and lossless two-dimensional data compression.

摘要

"reversible transform for lossless and lossless two-dimensional data compression". This is a 2d transform and its inverse that has an implementation as a sequence of survey steps for reduced computational complexity (ie, reducing a number of nontrivial operations). This pair of transforms has energy compression properties similar to the discrete cosine transform (dct), and is also lossless and scaled free. As compared to a separable dct transform implemented as 1d dct transforms applied separately to rows and columns of a 2d data block, transform operations are rearranged within a cascade of elementary transforms, including the 2x2 hadamard transform, and transforms 2x2 incorporating lifting rotations. These elementary transforms have implementations as a sequence of survey operations.