Embedding and detecting watermarks based on embedded positions in document layout
US7873183B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 2009 |
| Grant date | Jan 18, 2011 |
| Priority date | — |
| Expiry date | Oct 21, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/608
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A watermark embedding method for embedding a secret message sequence in a document. The techniques include obtaining layout information of the document, extracting a digest of the document by using a Hash function, calculating embedded positions where the secret message sequence is embedded in the document, and dispersedly hiding the secret message sequence in each of the calculated embedded positions by altering the layout of the document. Also provided is a watermark embedding apparatus, a corresponding watermark detecting method and apparatus, and a method and system for detecting document integrity. The integrity of documents in various forms can be detected, and secret information to be hidden can be embedded therein and extracted therefrom. The techniques described are not limited to the document either in soft copy or in hard copy and have good robustness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.