Interval centroid based watermark
US7724782B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2008 |
| Grant date | May 25, 2010 |
| Priority date | — |
| Expiry date | Sep 12, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2463/103
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An interval centroid-based watermark encoder encodes a watermark into a packet flow. Intervals are defined for the packet flow. Some of the intervals are selected as group A intervals while other intervals are selected as group B intervals. Group A and group B intervals are paired and assigned to watermark bits. A first or second value may be encoded by increasing the relative packet time between packets in either the group A (for the first bit value) or group B (for the second bit value) interval(s) of the interval pair(s) assigned to the watermark bits that are to represent the first or second bit value and the beginning of the same group interval(s). The relative packet times may be measured by a decoder and used to calculate a centroid difference for each interval pair. The centroid differences may be used to reconstruct the watermark.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.