Method and apparatus for detecting processing stages applied to a signal
US7046808B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 2000 |
| Grant date | May 16, 2006 |
| Priority date | — |
| Expiry date | Mar 24, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2201/0202
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system for determining the amount of processing that has been applied to watermarked signal. A steganographic signal is provided that includes an original signal and an embedded fragile watermark. The fragile watermark is characterized by a low energy and a high redundancy in comparison to a robust watermark. The steganographic signal is communicated over a distribution channel to a decoder. At the decoder, a measure of a presence of the fragile watermark in the acquired steganographic signal is provided, along with an estimate of the fragility profile of the fragile watermark for this particular original signal. Based on these factors, a estimate is made of the amount of processing that the steganographic signal has undergone. This processing can include, for example, A/D and D/A conversions, resampling, band-limiting, perceptual compression/decompression, etc. Optionally, the fragility profile is derived prior to the distribution of the content and communicated by the steganographic signal for recovery by the decoder. Furthermore, a robust watermark may be provided in the steganographic signal that, e.g., designates the presence of the fragile watermark to a decoder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.