EFFICIENT AND SECURE FORENSIC MARKING IN COMPRESSED DOMAIN

• US 20090326961A1
• Filed: 06/19/2009
• Published: 12/31/2009
• Est. Priority Date: 06/24/2008
• Status: Active Grant

• Current Assignee: Vobile Incorporated (Vobile Group Ltd.)
• Original Assignee: Verance Corporation
• Inventors: Petrovic, Rade, Yang, Dai
• Granted Patent: US 8,259,938 B2
• Time in Patent Office: Days
• US Class Current: 704/500
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G10L 19/018 Audio watermarking, i.e. embedding inaudible data in the audio signal

Abstract

Methods, devices, and computer program products enable the embedding of forensic marks in a host content that is in compressed domain. These and other features are achieved by preprocessing of a host content to provide a plurality of host content versions with different embedded watermarks that are subsequently compressed. A host content may then be efficiently marked with forensic marks in response to a request for such content. The marking process is conducted in compressed domain, thus reducing the computational burden of decompressing and re-compressing the content, and avoiding further perceptual degradation of the host content. In addition, methods, devices and computer program products are disclosed that obstruct differential analysis of such forensically marked content.

Claims

1. A method comprising:

receiving metadata associated with a request for a host content at a marking module;

generating a code with a code generator in accordance with the metadata;

selecting a plurality of content segments from a plurality of tributaries that are in compressed domain in accordance with the code, the tributaries comprising one or more versions of the host content having been contiguously embedded with a unique string of watermark symbols and compressed thereafter;

assembling the segments to produce a forensically marked host content in compressed domain; and

delivering the forensically marked host content to at least one of a content handling device or a computer readable storage medium.

2. The method of claim 1, wherein the metadata comprises information for identifying the request, the information comprising at least one of a transaction identification, intended destination of the forensically marked host content, and time, date, and source of the request

3. The method of claim 1, wherein the tributaries comprise an unmarked host content.

4. The method of claim 1, wherein the tributaries comprise compression units, each compression unit having been embedded with a watermark symbol, and each compressing unit corresponding to at least one of a time, a space, and a time-and-space domains.

5. The method of claim 4, wherein the watermark symbol spans an integer multiple number of the compression units.

6. The method of claim 1, wherein the host content is an audio content, and the tributaries are produced using at least one of an AAC, AACplus, and MP3 compression techniques.

7. The method of claim 1, wherein the host content is an audio content, the tributaries are compressed using a AAC compressor, and the selecting comprises:

selecting a first segment from a first tributary in accordance with a first symbol of the code;

selecting a second segment in accordance with a second symbol of the code, wherein;

if the second symbol is the same as the first symbol, selecting the second segment from the first tributary, and

if the second symbol is different from the first symbol, selecting the second segment from a second tributary.

8. The method of claim 7, wherein if selecting the second segment from a second tributary creates perceptual artifacts, selecting the second segment from the first tributary.

9. The method of claim 1, wherein the tributaries are modified in accordance with one or more distortions.

10. The method of claim 9, wherein the distortions comprise at least one of non-linear amplitude modifications of the host content samples, phase offsets applied to the plurality of tributaries, and modifying Dynamic Range Control (DRC) bits associated with the tributaries that are in AAC format.

11. An apparatus comprising:

a receiver configured to receive metadata associated with a request for a host content;

a code generator configured to generate a code in accordance with the metadata;

a selector configured to select a plurality content segments from a plurality of tributaries that are in compressed domain in accordance with the code, the tributaries comprising one or more versions of the host content having been contiguously embedded with a unique string of watermark symbols and compressed thereafter; and

an assembly means configured to assemble the segments to produce a forensically marked host content in compressed domain.

12. The apparatus of claim 11, wherein the metadata comprises information for identifying the request, the information comprising at least one of a transaction identification, intended destination of the forensically marked host content, and time, date, and source of the request.

13. The apparatus of claim 11, wherein the selector is configured to select one or more content segments from a tributary that comprise an unmarked host content.

14. The apparatus of claim 11, wherein the selector is configured to select one or more content segments from the tributaries comprising compression units, each compression unit having been embedded with a watermark symbol, and each compressing unit corresponding to at least one of a time, a space, and a time-and-space domains.

15. The apparatus of claim 14, wherein the watermark symbol spans an integer multiple number of the compression units.

16. The apparatus of claim 11, wherein the host content is an audio content, and the tributaries are produced using at least one of an AAC, AACplus, and MP3 compression techniques.

17. The apparatus of claim 11, wherein the host content is an audio content, the tributaries are produced using a AAC compressor, and the selector is configured to:

select a first segment from a first tributary in accordance with a first symbol of the code; and

select a second segment in accordance with a second symbol of the code, wherein;

if the second symbol is the same as the first symbol, the selector is configured to select the second segment from the first tributary, and

if the second symbol is different from the first symbol, the selector is configured to select the second segment from a second tributary.

18. The apparatus of claim 17, wherein if selecting the second segment from a second tributary creates perceptual artifacts, the selector is configured to select the second segment from the first tributary.

19. The apparatus of claim 11, further configured to modify the tributaries in accordance with one or more distortions.

20. The apparatus of claim 19, wherein the distortions comprise at least one of non-linear amplitude modifications of the host content samples, phase offsets applied to the plurality of tributaries, and modifying Dynamic Range Control (DRC) bits associated with the tributaries that are in AAC format.

21. A computer program product, embodied on a computer readable medium, the computer program product comprising:

a computer code for receive metadata associated with a request for a host content;

a computer code for generating a code in accordance with the metadata;

a computer code for selecting a plurality of content segments from a plurality of tributaries that are in compressed domain in accordance with the code, the tributaries comprising one or more versions of the host content having been contiguously embedded with a unique string of watermark symbols and compressed thereafter; and

a computer code for assembling the segments to produce a forensically marked host content in compressed domain.

22. The computer program product of claim 21, wherein the metadata comprises information for identifying the request, the information comprising at least one of a transaction identification, intended destination of the forensically marked host content, and time, date, and source of the request.

23. The computer program product of claim 21, wherein the tributaries comprise an unmarked host content.

24. The computer program product of claim 21, wherein the tributaries comprise compression units, each compression unit having been embedded with a watermark symbol, and each compressing unit corresponding to at least one of a time, a space, and a time-and-space domains.

25. The computer program product of claim 24, wherein the watermark symbol spans an integer multiple number of the compression units.

26. The computer program product of claim 21, wherein the host content is an audio content, and the tributaries are produced using at least one of an AAC, AACplus, and MP3 compression techniques.

27. The computer program product of claim 21, wherein the host content is an audio content, the tributaries are produced using a AAC compressor, and the selecting comprises:

selecting a first segment from a first tributary in accordance with a first symbol of the code;

selecting a second segment in accordance with a second symbol of the code, wherein;

if the second symbol is the same as the first symbol, selecting the second segment from the first tributary, and

if the second symbol is different from the first symbol, selecting the second segment from a second tributary.

28. The computer program product of claim 27, wherein if selecting the second segment from a second tributary creates perceptual artifacts, selecting the second segment from the first tributary.

29. The computer program product of claim 21, wherein the tributaries are modified in accordance with one or more distortions.

30. The computer program product of claim 29, wherein the distortions comprise at least one of non-linear amplitude modifications of the host content samples, phase offsets applied to the plurality of tributaries, and modifying Dynamic Range Control (DRC) bits associated with the tributaries that are in AAC format.

31. A method comprising:

embedding a host content contiguously with a first watermark symbol at a preprocessing module to produce a first embedded host content;

compressing the first embedded host content to produce a first tributary;

producing a second tributary comprising a compressed content; and

making available the first and the second tributaries to a marking module on a processing device, wherein selection and assembly by the marking module of a plurality of content segments from the first and second tributaries in accordance with a generated code produces a forensically marked host content in compressed domain.

32. The method of claim 31, wherein the second tributary is produced by compressing an unmarked host content.

33. The method of claim 31, wherein the second tributary is produced by:

embedding the host content contiguously with a second watermark symbol to produce a second embedded host content; and

compressing the second embedded host content.

34. An apparatus comprising:

an embedder configured to embed a host content contiguously with a first watermark symbol to produce a first embedded host content;

a compressor configured to compress the first embedded host content and a second content to produce a first tributary and a second tributary, respectively, wherein selection and assembly of a plurality of content segments from the first and second tributaries in accordance with a generated code produces a forensically marked host content in compressed domain.

35. The apparatus of claim 34, wherein the second content comprises an unmarked host content.

36. The apparatus of claim 34, wherein the embedder is configured to produce the second content by embedding the host content contiguously with a second watermark symbol.

37. A computer program product, embodied on a computer readable medium, comprising:

program code for embedding a host content contiguously with a first watermark symbol at a preprocessing module to produce a first embedded host content;

program code for compressing the first embedded host content to produce a first tributary;

program code for producing a second tributary comprising a compressed content, wherein selection and assembly of a plurality of content segments from the first and second tributaries in accordance with a generated code produces a forensically marked host content in compressed domain.

38. The computer program product of claim 37, comprising program code for producing the second tributary by compressing an unmarked host content.

39. The computer program product of claim 37, comprising

program code for embedding the host content contiguously with a second watermark symbol to produce a second embedded host content;

and

program code for producing the second tributary by compressing the second embedded host content.