Blocks of audio are encoded based upon corresponding first and second frequencies. The first and second frequencies are hopped from block to block. An audio quality measure (AQM) is computed for each block of audio such that, if x out of y blocks of audio have an AQM greater than a first predetermined threshold, encoding is suspended. For example, x may be nine and y may be 16. Also, if a ratio of the energy in a front part of a block of audio to the energy in a rear part of the block of audio is greater than a second predetermined threshold, that block of audio is not encoded even though x out of y blocks of audio have an AQM greater than the first predetermined threshold. Multiple distributors of the audio may encode the audio with their corresponding identities using the above processes.
RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 09/116,397 filed Jul. 16, 1998, now issued as U.S. Pat. No. 6,272,176. This application also contains disclosure similar to the disclosure in U.S. patent application Ser. No. 09/427,970.
An information encoding apparatus and method, an information decoding apparatus and method, a recording medium, and a program make it possible to embed information without causing an increase in the amount of data of compressed audio signals. A spectrum measurer converts an audio signal from a time axis signal into a frequency axis signal. A compressor removes frequency spectra having levels below a minimum audible threshold value. An embedability determiner determines whether information can be embedded. A spectrum switcher embeds information in an audio signal by switching or by not switching predetermined first frequency spectrum and second frequency spectrum under the control of an information adder. The present invention is applicable to a disk recording apparatus.
The present invention relates to a digital audio watermark inserting/detecting method and apparatus. The present invention provide the digital audio watermark inserting method having the step of encoding a digital audio signal by using a scale factor table, the method including the steps of: transforming the digital audio signal into a plurality of sub-band samples; extracting a scale factor being an amplitude factor of the transformed sub-band samples; transforming the extracted scale factor into a scale factor index by using the scale factor table; and inserting a watermark signal into the scale factor index in the transforming of the extracted scale factor. Accordingly, the present invention has an effect in that the additional noise or distortion is not caused while the watermark is effectively inserted.
An apparatus for the remote monitoring of audio signals, such as radio broadcasts or the audio portion of television broadcasts, includes a portable transponder intended to be worn or carried by a potential audience member and a receiver. The receiver contains circuitry for perceiving audio present in a monitored region and identifying an audio signal of interest. It also contains circuitry for detecting the presence of the transponder in the monitored region and creating a record associating the dwell time of the transponder and thus the audience member in the monitored region with the audio signal.
The invention provides a method of forensic digital watermarking that randomly selects an orientation and/or embedding protocol for a digital watermark signal to be embedded in the content signal. It then embeds the digital watermark signal at the selected orientation in the content signal. The embedding applies a different orientation to the forensic watermark for each instance of embedding a watermark. This thwarts averaging and over-embedding attacks.
Novel methods and systems for quantization based data embedding and reading in host signals, such as image, audio and video signals. To embed auxiliary data in a host signal, an embedder maps the host signal from a first domain into a mapped signal in a second domain that is robust to a class of amplitude modifications that are order preserving. The embedder performs quantization based embedding of auxiliary data into the host signal using quantization bins derived from the second domain that are robust to the amplitude modifications. The mapping improves the robustness of the data embedding method by increasing the chances that the embedded data can be recovered by an auxiliary data reader after amplitude modifications. A related embedding method projects the mapped signal unto a vector, and specifically, a pseudorandom vector. It performs quantization based embedding on the projected signal. The use of this projection provides added robustness of the embedded data to noise and other forms of distortion.
