Methods and systems using multiple watermarks
First Claim
1. A method of steganographically encoding an object with auxiliary information, characterized by adding first and second data to the object to thereby steganographically encode same, the first data having a relatively higher likelihood of withstanding a corruption operation, the second data having a relatively lower likelihood of withstanding said corruption option.
6 Assignments
0 Petitions
Accused Products
Abstract
Two or more digital watermarks, with different characteristics, are embedded in a document. The characteristics are chosen so that the watermarks will be affected in different manners if the document is subsequently copied or reproduced. The detection process or mechanism reads two or more of the watermarks and compares their characteristics. While wear and handling may change the characteristics of the digital watermarks in a document, the relationship between the characteristics of the multiple digital watermarks in a document will nevertheless give an indication as to whether a document is an original or a copy of an original. Document wear can be independently assessed and used as an aid in interpreting the detected watermark characteristics.
65 Citations
9 Claims
- 1. A method of steganographically encoding an object with auxiliary information, characterized by adding first and second data to the object to thereby steganographically encode same, the first data having a relatively higher likelihood of withstanding a corruption operation, the second data having a relatively lower likelihood of withstanding said corruption option.
Specification