Audio watermarking with dual watermarks
US7197368B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 15, 2003 |
| Grant date | Mar 27, 2007 |
| Priority date | — |
| Expiry date | Jul 15, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2005/91335
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A watermark encoding system encodes an audio signal with both a strong and a weak watermark. The strong watermark identifies the content producer and is designed to survive all typical kinds of processing and malicious attacks. The weak watermark identifies the content as an original and is designed to be significantly removed as a result of most normal signal processing (other than A/D and D/A). The watermark encoding system has a converter to convert an audio signal into frequency and phase components and a mask processor to determine a hearing threshold for corresponding frequency components. The watermark encoding system also has a pattern generator to generate both the strong and weak watermarks and a watermark insertion unit to selectively insert either the strong or weak watermark into the audio signal. The watermark insertion unit adds the strong watermark to the audio signal when the signal exceeds the hearing threshold by a buffer value (e.g., 1–8 dB) and adds the weak watermark insertion unit when the signal falls below the hearing threshold by the buffer value. When the signal falls within the buffer area about the hearing threshold, the insertion unit takes no action. …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.