Field-based watermark insertion and detection
US5991426A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1998 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Dec 18, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N1/32304
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital watermark is inserted into multimedia data containing two image fields by placing a positive watermark into a first field and a negative watermark into a second field. The positive watermark and negative watermark are opposite of one another. The two fields can be interlaced fields of a field-based video signal or alternate rows of a frame-based video signal. The watermark is extracted from field-based watermarked data by separating the watermarked data into two fields and subtracting one of the fields from the other field to generate a watermarked signal. The resultant watermarked signal is processed in a conventional manner to extract and detect the watermark.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.