Methods and apparatus to perform audio watermarking and watermark detection and extraction
US9460730B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 28, 2012 |
| Grant date | Oct 4, 2016 |
| Priority date | — |
| Expiry date | Apr 8, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04H2201/50
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Encoding and decoding methods and apparatus are described to obtain auxiliary information from an audio signal. The auxiliary information uses a plurality of frequency components residing in a plurality of code bands. The audio signal is transformed into a frequency domain representation. Characteristics of frequencies of the frequency domain representation that may contain the auxiliary information are determined. The characteristics of frequencies of the frequency domain representation in a respective one of the code bands that may contain the auxiliary information are normalized across the code band. The normalization is carried out against a characteristic of a frequency in that code band. The normalized characteristics of the frequencies representative of auxiliary information are summed to determine a sum for a frequency representative of auxiliary information. It is determined when the sum is representative of the auxiliary information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.