Image processing using embedded registration data to determine and compensate for geometric transformation

• US 8,243,980 B2
• Filed: 03/09/2004
• Issued: 08/14/2012
• Est. Priority Date: 04/25/1996
• Status: Expired due to Fees

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B., Sharma, Ravi K.
• Primary Examiner(s): Ahmed, Samir
• Assistant Examiner(s): ALLISON, ANDRAE S
• Application Number:
  US10/797,617
• Publication Number:
  US 20040264733A1
• Time in Patent Office: 3,080 Days
• Field of Search: 382/100, 382/280, 382/284, 382/232, 713/201, 713/179, 381/731, 380/4, 380/9, 358/124, 358/142, 348/448, 283/6, 283/17
• US Class Current: 382/100
• CPC Class Codes: G06T 1/0064 Geometric transfor invariant watermarking, e.g. affine transform invariant
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G06T 2201/0052 Embedding of the watermark in the frequency domain
• 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 1/32144 embedded in the image data, i.e. enclosed or integrated in the image, e.g. watermark, super-imposed logo or stamp
• 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 1/3216 using Fourier transforms
• CPC Class Codes: H04N 1/3232 Robust embedding or watermarking
• 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 2201/328 : Processing of the additional information

Abstract

Registration data embedded in an image is used to determine and compensate for geometric transformation of the image. The registration data may include frequency domain features of the image that are used to compute the rotation and/or scaling of the image. The registration method may be used in conjunction with digital watermarking and other signal processing applications.

Claims

1. A method comprising:

detecting, with a processor of a computing device, one or more registration signals from image data, wherein the image data includes electronic signals, and wherein the detecting includes processing the electronic signals to detect the one or more registration signals in the electronic signals;

adding, with the processor of the computing device, two or more image blocks together from the image data to increase a signal-to-noise ratio of the one or more registration signals;

determining, with the processor of the computing device, one or more frequency properties of the image data;

identifying, with the processor of the computing device, a geometric transformation to which the image data is subjected based at least in part on the one or more detected registration signals and the one or more frequency properties; and

using the identified geometric transformation to compute registered image data.

combining the plurality of blocks to reconstruct an image corresponding to the image data.

2. The method according to claim 1, further comprising transforming the image data into frequency components.

3. The method according to claim 1, wherein the detremining is based at least in part on one or more frequency components of the image data.

4. The method according to claim 1, further comprising:

performing a Fourier transformation on at least a portion of the image date; and

converting one or more frequency components of the image data into amplitude spectra.

5. The method according to claim 1, further comprising:

dividing the image data into a plurality of blocks; and

combining the plurality of blocks to reconstruct an image corresponding to the image data.

6. The method according to claim 1, wherein the geometric transformation comprises scaling.

7. A device comprising:

registration signal detecting means for detecting one or more registration signals from image data;

adding means for adding two or more image blocks together from the image data to increase a signal-to-noise ratio of the one or more registration signals;

frequency property determining means for determining one or more frequency properties of the image data;

geometric transformation identifying means for identifying a geometric transformation to which the image data is subjected based at least in part on the one or more detected registration signals and the one or more frequency properties; and

geometric transforming means for using the identified geometric transformation to compute registered image data.

8. A non-transitory computer readable medium having computer-readable instructions stored thereon, the instructions comprising:

instructions to detect one or more registration signals from image data;

instructions to add two or more image blocks together from the image data to increase a signal-to-noise ratio of the one or more registration signals;

instructions to determine one or more frequency properties of the image data;

instructions to identify a geometric transformation to which the image data is subjected based at least in part on the one or more detected registration signals and the one or more frequency properties; and

instructions to use the identified geometric transformation to compute registered image data.

9. A device comprising:

a memory configured to store image data; and

a processor operatively coupled to the memory and configured to;

detect one or more registration signals from the image data;

add two or more image blocks together from the image data to increase a signal-to-noise ratio of the one or more registration signals;

determine one or more frequency properties of the image data;

identify a geometric transformation to which the image data is subjected based at least in part on the one or more registration signals and the one or more frequency properties; and

use the identified geometric transformation to compute registered image data.

10. A method comprising:

transforming, with a processor of a computing device, a media signal into a frequency domain to produce one or more frequency components of the media signal;

detecting an embedded signal in the one or more frequency components;

adding two or more data blocks together from the media signal to increase a signal-to-noise ratio of the embedded signal;

based on the detecting, determining one or more geometric transformation parameters defining a geometric transformation of the media signal; and

using the one or more geometric transformation parameters to transform the media signal.

11. The method of claim 10, wherein the one or more frequency components are computed using a Fourier transform.

12. The method of claim 10, further comprising pre-filtering the media signal to attenuate noise relative to the embedded signal.

13. The method of claim 10, further comprising performing a log sampling of the media signal.

14. The method of claim 10, further comprising performing a log-log sampling of the media signal.

15. The method of claim 10, further comprising performing a log-polar sampling of the media signal.

16. The method of claim 10, wherein the media signal comprises an electronic signal representing audio or image signals stored in a memory.

17. The method of claim 16, wherein the image signals comprise video.

18. A non-transitory computer readable medium having computer-readable instructions stored thereon, the instructions comprising:

instructions to transform a media signal into a frequency domain to produce one or more frequency components of the media signal;

instructions to detect an embedded signal in the one or more frequency components;

instructions to determine, based on the detecting, one or more geometric transformation parameters defining a geometric transformation of the media signal; and

instructions to use the one or more geometric transformation parameters to transform the media signal.

19. A device comprising:

a memory configured to store a media signal; and

a processor operatively coupled to the memory and configured to;

transform the media signal into a frequency domain to produce one or more frequency components of the media signal;

detect an embedded signal in the one or more frequency components;

add two or more data blocks together from the media signal to increase a signal-to-noise ratio of the embedded signal;

determine, based on the detecting, one or more geometric transformation parameters defining a geometric transformation of the media signal; and

use the one or more geometric transformation parameters to transform the media signal.