Watermarking Compressed Data
First Claim
1. A method of embedding auxiliary data in coefficients generated for a compressed data stream, the method comprising:
- receiving coefficients in the data stream, the coefficients being divided into blocks;
changing the value of selected coefficients to embed multi-bit message data in the coefficients, the changing including controlling changes to the selected coefficients from different blocks so that the relationship of the selected coefficients from the different blocks satisfy an embedding rule.
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Accused Products
Abstract
A method of embedding auxiliary data in coefficients generated for a compressed data stream applies embedding rules to selected coefficients in different blocks to embed the data. The method receives coefficients in a data stream in which the coefficients are divided into blocks. It changes the value of selected coefficients to embed multi-bit message data in the coefficients. The process of changing the coefficients includes controlling changes to the selected coefficients from different blocks so that the relationship of the selected coefficients from the different blocks satisfy an embedding rule. One embedding rule causes the embedded data to form a pattern across the blocks. Another rule causes coefficients of blocks to have a desired phase relationship. Another rule enforces entropy and/or bit rate constraints onto the data stream. These embedding rules facilitate data hiding within bit rate and perceptibility constraints, while increasing robustness.
70 Citations
15 Claims
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1. A method of embedding auxiliary data in coefficients generated for a compressed data stream, the method comprising:
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receiving coefficients in the data stream, the coefficients being divided into blocks;
changing the value of selected coefficients to embed multi-bit message data in the coefficients, the changing including controlling changes to the selected coefficients from different blocks so that the relationship of the selected coefficients from the different blocks satisfy an embedding rule. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14)
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13. A method of embedding auxiliary data in coefficients generated for a compressed data stream, the method comprising:
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receiving coefficients in the data stream; and
changing the value of selected coefficients to embed multi-bit message data in the coefficients, the changing including controlling changes to entropy codes representing the selected coefficients, the changing of the entropy codes being made so as to satisfy an established bit rate constraint. - View Dependent Claims (15)
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Specification