Method and device for watermark-based image integrity verification
AssigneeIndustry-Academia Cooperation Group of Sejong University
InventorOh Jin Kwon
Life of this patent
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Abstract
The present disclosure provides a method of embedding a watermark on a Joint Photographic Experts Group (JPEG) image. The method includes: performing an entropy decoding on the JPEG image to generate quantized discrete cosine transform (DCT) coefficients; determining target bits in a bit plane of the quantized DCT coefficients on the basis of a watermark-embedding table (WET); and embedding a watermark based on metadata of the JPEG image in the target bits. Also, the present disclosure provides a method of verifying integrity of the image by using the embedded watermark.
Claims16
A method of embedding a watermark in a Joint Photographic Experts Group (JPEG) image for verifying integrity of the JPEG image, the method comprising:
- performing an entropy decoding on the JPEG image to generate quantized discrete cosine transform (DCT) coefficients;
- determining target bits in a bit plane of the quantized DCT coefficients according to a predetermined rule and generating a plurality of groups 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
- embedding a watermark based on metadata of the JPEG image in the target bits,
- wherein embedding the watermark based on the metadata of the JPEG image in the target bits comprises:
- generating 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;
- generating a random bit sequence (RBS) for each child GOB on the basis of the BIK for each child GOB;
- and
- embedding the RBS for each child GOB in the target bits of the GOB.
A method of verifying integrity of a Joint Photographic Experts Group (JPEG) image in which a watermark is embedded, the method comprising:
- performing an entropy decoding on the JPEG image to generate quantized discrete cosine transform (DCT) coefficients;
- determining target bits in a bit plane of the quantized DCT coefficients according to a predetermined rule and generating a plurality of groups 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;
- extracting a first watermark from the target bits;
- generating a block identifying key (BIK) for each child GOB on the basis of the child GOB information including 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 PEG image, and a user key, and
- generating a random bit sequence (RBS) for each child GOB on the basis of the BIK for each child GOB as a second watermark;
- and
- comparing the first watermark with the second watermark to verify the integrity of the image.
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.
Dependencies are inferred from the claim text.