High frequency masking of embedded digital data to improve appearance
US6427920B1 · kind B1 · utility
6Cited by
7References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 24, 1999 |
| Grant date | Aug 6, 2002 |
| Priority date | — |
| Expiry date | Sep 24, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K19/06
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A specific bit pattern (or set of bit patterns) that have particular frequency and length requirements is used to remove low-frequency, visually observable structure from rendered embedded digital data. In use, the pattern is replicated enough times to be able to XOR with the data before rendering as glyphs, or the like. On decoding (reading), the read data is XOR'd again to recover the original data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.