Patent ID: 11889098
Assignee: DOLBY INTERNATIONAL AB
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method for encoding a sign-data-hiding enabled data signal representative of at least one image comprising a plurality of partitions, the method comprising:
setting a partition of an image comprising a set of coefficients;
identifying a first non-zero coefficient within the set of coefficients;
identifying a last non-zero coefficient within the set of coefficients;
determining a set of modifiable coefficients in the set of coefficients, wherein the set of modifiable coefficients include the first non-zero coefficient, the last non-zero coefficient and all the coefficients between the first non-zero coefficient and the last non-zero coefficient;
determining a count of coefficients in the set of modifiable coefficients;
comparing the count to a plurality of threshold values, including a first threshold value and a second threshold value that is greater than the first threshold value;
in response to determining that the count is greater than the first threshold value but less than the second threshold value:
calculating a sum of amplitude information of non-zero coefficients in the set of modifiable coefficients;
calculating, using the sum of amplitude information, parity data;
comparing, based on the parity data, signs of a particular plurality of non-zero coefficients to a particular sign configuration in a predetermined plurality of sign configurations; and
when the signs of the particular plurality of non-zero coefficients matches the particular sign configuration, encoding the particular plurality of non-zero coefficients into a bitstream without corresponding sign bits.