Patent ID: 11915336
Assignee: INDUSTRY-ACADEMIA COOPERATION GROUP OF SEJONG UNIVERSITY
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 13:
14. A device for embedding a watermark in a Joint Photographic Experts Group (JPEG) image for verifying integrity of the JPEG image, comprising:
a processor; and
a memory storing at least one instruction to be executed by the processor,
wherein the at least one instruction when executed by the processor causes the processor to:
perform an entropy decoding on the JPEG image to generate quantized discrete cosine transform (DCT) coefficients;
determine target bits in a bit plane of the quantized DCT coefficients according to a predetermined rule and generate a plurality of croups of blocks (GOBs) having a tree structure based on a plurality of blocks in the bit plane such that each child GOB includes at least one target bit; and
embed a watermark based on metadata of the JPEG image in the target bits,
wherein the at least one instruction causing the processor to embed the watermark based on the metadata of the JPEG image in the target bits causes the processor to:
generate a block identifying key (BIK) for each child GOB on the basis of child GOB information comprising information about bits that are not included in the target bits in the child GOBs and the branch chain information of the child GOB, the metadata of the JPEG image, and a user key;
generate a random bit sequence (RBS) for each child GOB on the basis of the BIK for each child GOB; and
embed the RBS for each child GOB in the target bits of the GOB.