Method and apparatus for multi-bit zoned data hiding in printed images
US6212285A · kind A · utility
27Cited by
5References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1998 |
| Grant date | Apr 3, 2001 |
| Priority date | — |
| Expiry date | Apr 15, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/327
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A technique for embedding a tracking number as a series of bits in a printed image alters characteristic parameter values at a set of pseudo-random locations chosen for each bit in an embedding zone. The alteration markedly changes the expectation value of some linear combination of mathematical functions of the values at that set of locations. A marker bit encoded to a higher certainty than other bits in the string aids in orienting the zones in decoding. The tracking number is detected and identified by exploiting the behavior of sums of a large number of random variables, based on the Patchtrack approach.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.