Device and method for embedding binary payload in a carrier signal

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 information regarding the payload signal, to extract these bits. The inventive concept is simple in its implementation and may be scaled with respect to the data rate of the information to be inserted.

Description

technical field [0001] The present invention relates to a method of embedding a payload in a carrier signal and extracting the payload from the carrier, wherein the carrier signal can be an audio signal, a video signal or a multimedia signal containing audio and / or video signals. Background technique [0002] There are various applications and / or methods in the art of embedding side information in digital signals. Various known concepts in this technology are included in keyword watermarking. [0003] WO 97 / 33391 describes an encoding method for inserting an inaudible data signal into an audio signal. Wherein, in order to determine the shielding threshold of the audio signal by using the psychoacoustic mode, the inaudible data signal to be inserted into the audio signal is converted into a frequency domain signal through Fourier transform or improved discrete cosine transform. The data signal to be interpolated is multiplied by a pseudonoise signal to create a frequency ex...

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Problems solved by technology

In particular, decoders will often be in the hands of consumers, often not offering particularly high computing and storage resources due to their price competitiveness in the market

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