Reversible overlap operator for efficient lossless data compression
AssigneeMicrosoft Corporation
InventorsChengjie Tu, Henrique Malvar, Sridhar Srinivasan
Life of this patent
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Abstract
An efficient lapped transform is realized using pre- and post-filters (or reversible overlap operators) that are structured of unit determinant component matrices. The pre- and post-filters are realized as a succession of planar rotational transforms and unit determinant planar scaling transforms. The planar scaling transforms can be implemented using planar shears or lifting steps. Further, the planar rotations and planar shears have an implementation as reversible/lossless operations, giving as a result, a reversible overlap operator.
Claims21
A method of encoding and/or decoding digital media data tiled in blocks, the method comprising:
- applying a reversible overlap operator across at least some of the boundaries between blocks, the reversible overlap operator being unit determinant;
- and
- applying a reversible block transform to the blocks,
- wherein the applying the reversible overlap operator and the reversible block transform are inverted between encoding and decoding the digital media data.
A digital media encoder and/or decoder comprising:
- a data storage buffer for storing digital media data to be encoded and/or decoded;
- a processor programmed to:
- tile the digital media data into blocks;
- apply a reversible overlap operator across at least some of the boundaries between blocks, the reversible overlap operator being unit determinant;
- and
- apply a reversible block transform to the blocks,
- wherein application of the reversible overlap operator and the reversible block transform are inverted between encoding and decoding the digital media data.
At least one computer-readable recording medium carrying a computer-executable digital media processing program thereon for performing a method of processing digital media tiled in blocks, the method comprising:
- applying a reversible overlap operator across at least some of the boundaries between blocks, the reversible overlap operator being unit determinant;
- and
- applying a reversible block transform to the blocks,
- wherein the applying the reversible overlap operator and the reversible block transform are inverted between encoding and decoding the digital media data.
Dependencies are inferred from the claim text.