MULTI-LEVEL SIGNIFICANCE MAPS FOR ENCODING AND DECODING

摘要

Methods of encoding and decoding for video data are described in which multi-level significance maps are used in the encoding and decoding processes. The significant-coefficient flags that form the significance map are grouped into contiguous groups, and a significant-coefficient-group flag signifies for each group whether that group contains no non-zero significant-coefficient flags. If there are no non-zero significant-coefficient flags in the group, then the significant-coefficient-group flag is set to zero. The set of significant-coefficient-group flags is encoded in the bitstream. Any significant-coefficient flags that fall within a group that has a significant-coefficient-group flag that is non-zero are encoded in the bitstream, whereas significant-coefficient flags that fall within a group that has a significant-coefficient-group flag that is zero are not encoded in the bitstream.

主权项

1. A method for use in a decoder of a bitstream of encoded data for determining a value of a significant-coefficient flag corresponding to a transform coefficient of a block among one or more non-overlapping blocks within a transform unit, the significant-coefficient flag being a member of a group of significant-coefficient flags corresponding to the block, the group having a significant-coefficient-group flag, the method comprising:
upon determining that the value of the significant-coefficient-group flag is to be decoded from the bitstream and is one, determining the value of the significant-coefficient flag:
to be one when all of the other significant-coefficient flags of the group have been previously determined to have a value of zero, andotherwise by decoding the value from the bitstream.