Device and method for embedding binary payload in a carrier signal

US7587311B2 · kind B2 · utility

Assignee

• Fraunhofer-Gesellschaft zur förderung der angewandten Forschung e.V. · DE

Inventors

• Gerald Schuller · Erfurt, DE
• Ralf Geiger · Erlangen, DE
• Juergen Koller · Erlangen, DE

Key dates

• Filing date: Nov 15, 2005
• Grant date: Sep 8, 2009
• Expiry date: Mar 2, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G11B20/00891
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

For embedding binary payload in a carrier signal, which, for example, is an audio signal, a sequence of time-discrete values of the carrier signal is converted to the frequency domain by means of an integer transform algorithm to obtain binary spectral representation values. Bits of the binary spectral representation values with a valency less than signal limit valency are determined and set according to the payload. The signal limit valency for a spectral representation value is less than the valency of the leading bit of this spectral representation value, so that, with adequate distance, a psychoacoustic transparent insertion of information is achieved. Thus a modified spectral representation with inserted information is generated which is finally converted back to the time domain using an integer back transform algorithm. For extracting the payload, the time-discrete signal with the inserted information is again converted to a spectral representation with the integer forward transform algorithm. Furthermore, signal limit valency information is determined to identify the bits of the binary spectral representation values containing no information regarding the carrier signal, but…