US 11,388,401 B2 · Extended transform partitions for video compression

Abstract

Transform-level partitioning of a prediction residual block is performed to improve compression efficiency of video data. During encoding, a prediction residual block is generated responsive to prediction-level partitioning performed against a video block, a transform block partition type to use is determined based on the prediction residual block, a non-recursive transform-level partitioning is performed against the prediction residual block according to the transform block partition type, and transform blocks generated as a result of the transform-level partitioning are encoded to a bitstream. During decoding, a symbol representative of the transform block partition type used to encode transform blocks is derived from the bitstream, inverse transformed blocks are produced by inverse transforming encoded video data associated with the prediction residual block, and the prediction residual block is reproduced according to the transform block partition type and used to reconstruct the video block, which is output within an output video stream.

Claims20

Dependent claims

A method for encoding a video block, the method comprising:

performing prediction-level partitioning against the video block to partition the video block into one or more first sub-blocks;
generating a prediction residual block for a first sub-block of the one or more first sub-blocks based on a prediction of the first sub-block;
determining a transform block partition type for performing transform-level partitioning against the prediction residual block, wherein the transform block partition type is one of multiple transform block partition types available for partitioning the prediction residual block;
limiting transform-level partitioning performance to a single, non-recursive transform-level partitioning against the prediction residual block using the transform block partition type to partition the prediction residual block into a plurality of second sub-blocks;
generating a transform block for a second sub-block of the plurality of second sub-blocks by transforming video data of the second sub-block;
and
encoding the transform block and a symbol representative of the transform block partition type to a bitstream.

4 more elements

A method for decoding an encoded video block from a bitstream, the method comprising:

deriving a first symbol and a second symbol from the bitstream, the first symbol representing a first transform block partition type used during a transform-level partitioning performance limited to a single, non-recursive transform-level partitioning of a first prediction residual block including first video data of the encoded video block, the second symbol representing a second transform block partition type used during a transform-level partitioning performance limited to a single, non-recursive transform-level partitioning of a second prediction residual block including second video data of the encoded video block, wherein the first transform block partition type and the second transform block partition type are different;
producing the first prediction residual block according to the first symbol by inverse transforming and combining a plurality of first encoded transform sub-blocks associated with the first video data;
producing the second prediction residual block according to the second symbol by inverse transforming and combining a plurality of second encoded transform sub-blocks associated with the second video data;
reconstructing a video block including the first video data and the second video data using the first prediction residual block and the second prediction residual block;
and
outputting the video block within an output video stream for storage or display.

3 more elements

A method for decoding an encoded video block from a bitstream, the method comprising:

deriving, from a bitstream to which the encoded video block is encoded, a symbol representing a transform block partition type used during a transform-level partitioning performance limited to a single, non-recursive transform-level partitioning of a prediction residual block encoded to produce the encoded video block;
producing a first inverse transformed block by inverse transforming a first encoded transform sub-block associated with first video data of the prediction residual block;
producing a second inverse transformed block by inverse transforming a second encoded transform sub-block associated with second video data of the prediction residual block;
producing, according to the transform block partition type represented by the symbol, the prediction residual block using the first inverse transformed block and the second inverse transformed block;
reconstructing a video block including the first video data and the second video data using the prediction residual block;
and
outputting the video block within an output video stream for storage or display.

4 more elements

Dependencies are inferred from the claim text.

Extended transform partitions for video compression

Life of this patent

Extended transform partitions for video compression

Life of this patent

Abstract

Claims20