Steganographic encoding and decoding of auxiliary codes in media signals
US6944298B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | May 31, 2000 |
| Grant date | Sep 13, 2005 |
| Priority date | — |
| Expiry date | Sep 20, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/328
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
One aspect of the invention is a method of decoding an auxiliary code embedded in an audio signal. The method performs a statistical decoding of a multibit auxiliary code embedded in an audio signal. The auxiliary code has been repetitively embedded in the audio signal. The method decodes code values of the auxiliary code from two or more different portions of the audio signal, each having the multibit auxiliary code. It then uses the code values decoded from two or more different portions to determine statistically the code values of the auxiliary code. Another aspect of the invention is another method of decoding an auxiliary code embedded in an audio signal. The method receives an audio signal suspected of being embedded with an auxiliary code. It evaluates a statistical feature of a portion of the audio signal to decode code values of the auxiliary code from the audio signal. It then determines a code value in the auxiliary code based on the statistical feature. The statistical feature may comprise, for example, the power of the audio signal. The statistical feature may be analyzed over different portions of the audio signal to decode two or more values of the auxiliary code.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.