MULTIPLE SIGN BIT HIDING WITHIN A TRANSFORM UNIT

摘要

Methods of encoding and decoding for video data are described for encoding or decoding coefficients for a transform unit. In particular, the sign bits for the non-zero coefficients are encoded using sign bit hiding. Two or more sets of coefficients are defined for the transform unit and a sign bit may be hidden for each set, subject to satisfaction of a threshold test. The sets may correspond to coefficient groups that are otherwise used in multi-level significance map encoding and decoding.

主权项

1. A method of decoding a bitstream of encoded video by reconstructing coefficients for a transform unit, wherein the transform unit is partitioned into non-overlapping coefficient groups each containing a respective set of coefficients, and each of the non-zero coefficients having a sign bit indicating whether the coefficient is positive or negative, the method comprising:
for each of at least two coefficient groups in the transform unit,
decoding sign bits for all but one of the non-zero coefficients in that coefficient group;summing an absolute value of the coefficients in that coefficient group; andbased on whether the absolute value is even or odd, assigning a sign to the non-zero coefficient within that coefficient group for which a sign bit was not decoded.