Error Processing of Steganographic Message Signals

• US 20110158468A1
• Filed: 07/06/2010
• Published: 06/30/2011
• Est. Priority Date: 05/07/1996
• Status: Active Grant

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B.
• Granted Patent: US 8,184,849 B2
• Time in Patent Office: Days
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 1/005 Robust watermarking, e.g. average attack or collusion attack resistant
• CPC Class Codes: G06T 2201/0064 for copy protection or copy management, e.g. CGMS, copy only once, one-time copy
• CPC Class Codes: G06T 2201/0065 Extraction of an embedded watermark; Reliable detection
• CPC Class Codes: G06V 30/40 Document-oriented image-based pattern recognition
• CPC Class Codes: G10L 19/018 Audio watermarking, i.e. embedding inaudible data in the audio signal
• CPC Class Codes: H04N 1/00005 relating to image data
• CPC Class Codes: H04N 1/00037 Detecting, i.e. determining the occurrence of a predetermined state H04N1/00031 takes precedence
• CPC Class Codes: H04N 1/00079 remotely
• CPC Class Codes: H04N 1/32122 in a separate device, e.g. in a memory or on a display separate from image data
• CPC Class Codes: H04N 1/32149 Methods relating to embedding, encoding, decoding, detection or retrieval operations
• CPC Class Codes: H04N 1/32154 Transform domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/32203 Spatial or amplitude domain methods H04N1/32309 takes precedence
• CPC Class Codes: H04N 1/32229 with selective or adaptive application of the additional information, e.g. in selected regions of the image H04N1/32213 takes precedence
• CPC Class Codes: H04N 1/32288 Multiple embedding, e.g. cocktail embedding, or redundant embedding, e.g. repeating the additional information at a plurality of locations in the image
• CPC Class Codes: H04N 1/32352 Controlling detectability or arrangements to facilitate detection or retrieval of the embedded information, e.g. using markers for decoding, detection or retrieval operations H04N1/32149 and subgroups take precedence
• CPC Class Codes: H04N 21/23892 involving embedding information at multiplex stream level, e.g. embedding a watermark at packet level
• CPC Class Codes: H04N 21/8358 involving watermark protecting executable software by watermarking G06F21/16; image watermarking in general G06T1/0021; watermarks inserted in still images for transmission purposes H04N1/32144; inserting watermarks during video coding H04N19/467
• CPC Class Codes: H04N 2201/3205 of identification information, e.g. name or ID code H04N2201/3209 takes precedence
• CPC Class Codes: H04N 2201/3207 of an address
• CPC Class Codes: H04N 2201/3225 : of data relating to an image, a page or a document
• CPC Class Codes: H04N 2201/3226 : of identification information or the like, e.g. ID code, index, title, part of an image, reduced-size image
• CPC Class Codes: H04N 2201/3233 : of authentication information, e.g. digital signature, watermark
• CPC Class Codes: H04N 2201/327 : which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3271 : Printing or stamping
• CPC Class Codes: H04N 2201/3274 : Storage or retrieval of prestored additional information
• CPC Class Codes: H04N 2201/3284 : for error correction

Abstract

A form of error processing is used to decode steganographic messages embedded in image and audio signals in the presence of distortion, which tends to introduce errors in steganographic data communication. Content signals with auxiliary embedded data are analyzed to detect embedded message signals. Confidence values are assigned to the message signals and used to ascertain whether a message has been accurately detected. Error processing enables accurate message extraction in the presence of “soft errors” in the embedded message signal. This error processing enables more effective recovery of the steganographic message from content signals that undergo distortion and/or loss transformations after being embedded with steganographic data.

Claims

1. A method of decoding of steganographic data, the steganographic data being embedded in an electronic media signal by imperceptibly adjusting data values in the media signal to create a steganographically embedded signal, the method comprising using an electronic processor configured to:

process the electronic media signal to extract message values of the steganographic data;

assign confidence values to the message values based on signal statistics by which the values are determined; and

decode a corrected message from the message values weighted by the assigned confidence values.

2. The method of claim 1 wherein the message values and assigned confidence values are input to error correcting polynomial.

3. The method of claim 1 wherein the message values comprise binary bit values.

4. The method of claim 1 wherein the processing of the data values to extract message values includes performing statistical detection on the data values.

5. The method of claim 1 wherein the adjusted data values have been adjusted with positive and negative changes and the positive and negative changes correspond to different data states of the steganographic data.

6. The method of claim 1 wherein the adjusted data values have been adjusted with frequency components corresponding to a steganographic signal.

7. A computer readable medium on which is stored instructions, which, when executed by a computer, perform a method of decoding of steganographic data, the steganographic data being embedded in an electronic media signal by imperceptibly adjusting data values in the media signal to create a steganographically embedded signal, the method comprising using a programmed computer to:

process the electronic media signal to extract message values of the steganographic data;

assign confidence values to the message values based on signal statistics by which the values are determined; and

decode a corrected message from the message values weighted by the assigned confidence values.

8. A device for decoding of steganographic data, the steganographic data being embedded in an electronic media signal by imperceptibly adjusting data values in the media signal to create a steganographically embedded signal, the device comprising:

a memory for storing at least portions of the electronic media signal; and

a detector in communication with the memory for processing the electronic media signal to extract message values of the steganographic data, for assigning confidence values to the message values based on signal statistics by which the values are determined, and for decoding a corrected message from the message values weighted by the assigned confidence values.

9. The device of claim 8 wherein the message values and assigned confidence values are input to error correcting polynomial.

10. The device of claim 8 wherein the message values comprise binary bit values.

11. The device of claim 8 wherein the processing of the data values to extract message values includes performing statistical detection on the data values.

12. The device of claim 8 wherein the adjusted data values have been adjusted with positive and negative changes and the positive and negative changes correspond to different data states of the steganographic data.

13. The device of claim 8 wherein the adjusted data values have been adjusted with frequency components corresponding to a steganographic signal.