Data processing: speech signal processing – linguistics – language – Speech signal processing – Application
Reexamination Certificate
2000-12-08
2004-05-18
Abebe, Daniel (Department: 2655)
Data processing: speech signal processing, linguistics, language
Speech signal processing
Application
C713S193000
Reexamination Certificate
active
06738744
ABSTRACT:
TECHNICAL FIELD
This invention relates to protecting audio content by using watermarks. More particularly, this invention relates to improved techniques for detecting watermarks in an audio signal.
BACKGROUND
Since the earliest days of human civilization, music has existed at the crossroads of creativity and technology. The urge to organize sound has been a constant part of human nature while the tools to make and capture the resulting music have evolved in parallel with human mastery of science.
Throughout the history of audio recordings, the ability to store and transmit audio (such as music) has quickly evolved since the early days just 130 years ago. From Edison's foil cylinders to contemporary technologies (such as DVD-Audio, MP3, and the Internet), the constant evolution of prerecorded audio delivery has presented both opportunity and challenge.
Music is the world's universal form of communication, touching every person of every culture on the globe. Behind the music is a growing multi-billion dollar per year industry. This industry, however, is constantly plagued by lost revenues due to music piracy.
Protecting Rights
Piracy is not a new problem. However, as technologies change and improve, there are new challenges to protecting music content from illicit copying and theft. For instance, more producers are beginning to use the Internet to distribute music content. In this form of distribution, the content merely exists as a bit stream which, if left unprotected, can be easily copied and reproduced.
At the end of 1997, the International Federation of the Phonographic Industry (IFPI), the British Phonographic Industry, and the Recording Industry Association of America (RIAA) engaged in a project to survey the extent of unauthorized use of music on the Internet. The initial search indicated that at any one time there could be up to 80,000 infringing MP3 files on the Internet. The actual number of servers on the Internet hosting infringing files was estimated to 2,000 with locations in over 30 countries around the world. Since that survey, the availability of and interest in the digital music on the Internet has increased many times over.
Each day, the wall impeding the reproduction and distribution of infringing digital audio clips (e.g., music files) gets shorter and weaker. “Napster” is an example of an application that is weakening the wall of protection. It gives individuals access to one another's MP3 files by creating a unique file-sharing system via the Internet. Thus, it encourages illegal distribution of copies of copyrighted material.
As a result, these modern digital pirates effectively rob artists and authors of their lawful compensation. Unless technology provides for those who create music to be compensated for it, both the creative community and the musical culture at large will be impoverished.
Identifying a Copyrighted Work
Unlike tape cassettes and CDs, a digital music file has no jewel case, label, sticker, or the like on which to place the copyright notification and the identification of the author. A digital music file is a set of binary data without a detectible and unmodifiable label.
Thus, musical artists and authors are unable to inform the public that a work is protected by adhering a copyright notice to the digital music file. Furthermore, such artists and authors are unable to inform the public of any addition information, such as the identity of the copyright holder or terms of a limited license.
Digital Tags
The music industry and trade groups are especially concerned by digital recording because there is no generation loss in digital transfers—a copy sounds the same as the original. Without limits on unauthorized copying, a digital audio recording format could easily encourage the pirating of master-quality recordings.
One solution is to amend an associated digital “tag” with each audio file that identified the copyright holder. To implement such a plan, all devices capable of such digital reproduction must faithfully reproduce the amended, associated tag.
With the passage of the Audio Home Recording Act of 1992, inclusion of serial copying technology became law in the United States. This legislation mandated the inclusion of serial copying technology, such as SCMS (Serial Copy Management System), in consumer digital recorders. SCMS recognizes a “copyright flag” encoded on a prerecorded original (such as a CD), and writes that flag into the subcode of digital copies (such as a transfer from a CD to a DAT tape). The presence of the flag prevents an SCMS-equipped recorder from digitally copying the copy, thus breaking the chain of perfect digital cloning.
However, subsequent developments—both technical and legal—have demonstrated the limited benefits of this legislation. While digital-secure-music-delivery systems (such as SCMS) are designed to support the rights of content owners in the digital domain, the problem of analog copying requires a different approach. In the digital domain, information about the copy status of a given piece of music may be carried in the subcode, which is separate information that travels along with the audio data. In the analog domain, there is no subcode—the only place to put the extra information is to hide it within the audio signal itself.
Digital Watermarks
Techniques for identifying copyright information of digital audio content that address both analog and digital copying instances have received a great deal of attention in both the industrial community and the academic environment. One of the most promising “digital labeling” techniques is amalgamation of a digital watermark into the audio signal itself by altering the signal's frequency spectrum such that the perceptual characteristics of the original recording are preserved. In other words, a watermark is clandestinely integrated with an audio clip so that when copied, the watermark will be reproduced along with the clip itself.
In general, a “digital watermark” is a pattern of bits inserted into a digital representation (i.e., signal or file) of content (i.e., an image, audio, video, or the like) that identifies the content's copyright information (e.g., author, rights, etc.). The name comes from the faintly visible watermarks imprinted on stationery that identify the manufacturer of the stationery. The purpose of digital watermarks is to provide copyright protection for intellectual property that is in digital format.
Unlike printed watermarks, which are intended to be somewhat visible, digital watermarks are designed to be completely invisible, or in the case of audio clips, inaudible. That is invisible to all except a specifically designed watermark detector. Moreover, the actual bits representing the watermark are typically scattered throughout the file in such a way that they cannot be identified and manipulated. Finally, the digital watermark should be robust enough so that it can withstand normal changes to the file, such as reductions from lossy compression algorithms.
Satisfying all these requirements is no easy feat, but there are several competing technologies. All of them work by making the watermark appear as noise—that is, random data that exists in most digital files anyway. To view a watermark, you need a special program or device (i.e., a “detector”) that knows how to extract the watermark data.
Herein, such a digital watermark may be simply called a “watermark.” Generically, it may be called an “information pattern of discrete values” or a “data pattern of discrete values.” The audio signal (or clip) in which a watermark is encoded is effectively “noise” in relation to the watermark.
Watermarking
Watermarking gives content owners a way to self-identify each track of music, thus providing proof of ownership and a way to track public performances of music for purposes of royalty distribution. It may also convey instructions, which can be used by a recording or playback device, to determine whether and how the music may be distributed. Because that data can be read even after the music has been converted from digi
Kirovski Darko
Malvar Henrique
Abebe Daniel
Lee & Hayes PLLC
Microsoft Corporation
LandOfFree
Watermark detection via cardinality-scaled correlation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Watermark detection via cardinality-scaled correlation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Watermark detection via cardinality-scaled correlation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3264627