Geometrical transformation identifying system

• US 6,671,386 B1
• Filed: 05/21/1999
• Issued: 12/30/2003
• Est. Priority Date: 05/22/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Koido, Akioi, Shimizu, Shuichi
• Primary Examiner(s): Patel, Jayanti K.
• Assistant Examiner(s): CHAWAN, SHEELA C
• Application Number:
  US09/316,525
• Time in Patent Office: 1,684 Days
• Field of Search: 382/137, 382/232, 382/274, 382/250, 382/280, 382/115, 382/100, 382/298, 382/279, 382/199, 382/266, 382/269, 382/296, 235/382, 380/3, 380/4, 380/54, 380/59, 380/51, 380/55, 399/366, 399/84, 355/201, 713/176
• US Class Current: 382/100
• CPC Class Codes: G06F 18/00 Pattern recognition
• 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: G06T 2201/0083 whereby only watermarked image required at decoder, e.g. source-based, blind, oblivious

Abstract

A geometrical correction system and method comprising creation of at least one pattern consisting of asymmetric two dimensional waves, embedding at least one pattern consisting of asymmetric two dimensional waves in a real domain, and calculation of at least one geometrical transformation applied by way of extraction of the embedded two dimensional waves. Said creation of at least one pattern consisting of asymmetric two dimensional waves means to calculate a two dimensional wave parameter set for creating at least one pattern adapted for use in the geometrical correction system of this invention. Also, said embedding of at least one pattern consisting of asymmetric two dimensional waves in a real domain means to add the pattern to an original image. Further, said calculation of at least one geometrical transformation applied by way of extraction of the embedded two dimensional waves means to calculate parameters of the embedded two dimensional waves from the image that is subjected to at least one geometrical transformation, to compare these parameters with the two dimensional wave parameter set of the embedded pattern, thereby to identify the geometrical transformation applied to the embedded image.

Claims

1. A two dimensional wave embedding system for embedding two dimensional waves in an image to identify at least one geometrical transformation which has been applied to the image, comprising:

(a) means for storing the image into a storage means;

(b) means for generating and storing at least one pattern, consisting of a set of asymmetric two dimensional waves identifying the at least one geometrical transformation, into the storage means; and

(c) means for embedding said pattern of a set of asymmetric two dimensional waves identifying the at least one geometrical transformation which has been applied to the image in said stored image in a real domain.

2. The embedding system of claim 1, wherein said embedding system comprises a digital watermark embedding system and further comprises means for additionally embedding digital watermarks in said image that has said pattern embedded therein.

3. The system as set forth in claim 2 wherein said means for embedding said pattern is arranged to prevent degradation of image quality while embedding said pattern in the real domain.

4. The system as set forth in claim 1 wherein said means for embedding said pattern is arranged to prevent degradation of image quality while embedding said pattern in the real domain.

5. A position correcting pattern embedding system, comprising:

(a) means for storing an image of an object into a storage means;

(b) means for generating and storing at least one pattern, consisting of a set of asymmetric two dimensional waves representing correct positioning of said object, into the storage means;

(c) means for embedding said pattern comprising a set of asymmetric two dimensional waves representing correct positioning of said object in said stored image in a real domain; and

(d) means for embedding said image, which has said pattern embedded therein, in said object.

6. The system of claim 5 wherein said embedding said image comprises printing said image.

7. The system as set forth in claim 6 wherein said means for embedding said pattern is arranged to prevent degradation of image quality while embedding said pattern in the real domain.

8. The system as set forth in claim 5 wherein said means for embedding said pattern, is arranged to prevent degradation of image quality while embedding said pattern in the real domain.

9. A geometrical transformation identifying system for extracting two dimensional waves from an image that has said two dimensional waves embedded therein to identify at least one geometrical transformation which has been applied to the image, comprising:

(a) means for identifying and extracting said two dimensional waves, identifying at least one geometrical transformation which has been applied to the image, embedded in said image that is stored in a storage means;

(b) means for comparing predetermined asymmetric two dimensional waves with said extracted two dimensional waves; and

(c) means, responsive to a result of said comparison, for calculating at least one of a plurality of linear coordinate transformations applied to the image, said plurality of linear coordinate transformations including a scaling factor, a rotational angle, an inversion, an anisotropic scaling factor, and a parallel translation'"'"'s amount.

10. The system of claim 9 further comprising means for geometrically correcting said image by using said at least one calculated linear coordinate transformation.

11. The system of claim 10 further comprising means for extracting digital watermarks from said image that has been subjected to said geometrical correction.

12. The system of claim 9 further comprising means for performing position control of the object that has said image by using said at least one calculated linear coordinate transformation.

13. The system of claim 9 wherein said means for calculating at least one of a plurality of linear coordinate transformations is adapted to simultaneously calculate all of said plurality of linear coordinate transformations applied to said image.

14. A method of embedding two dimensional waves in an image for identifying at least one geometrical transformation which has been applied to the image, comprising the steps of:

(a) storing the image into a storage means;

(b) generating and storing at least one pattern, consisting of a set of asymmetric two dimensional waves identifying said at least one geometrical transformation, into the storage means; and

(c) embedding said generated pattern comprising a set of asymmetric two dimensional waves identifying said at least one geometrical transformation into said stored image in a real domain.

15. The method of claim 14 further comprising additionally embedding digital watermarks in said image that has said pattern embedded therein.

16. A method of extracting two dimensional waves from an image that has said two dimensional waves embedded therein to identify at least one geometrical transformation which has been applied to the image, comprising the steps of:

(a) identifying and extracting said two dimensional waves embedded in said image that is stored in a storage means said two dimensional waves identifying at least one geometrical transformation which has been applied to the image;

(b) comparing predetermined asymmetric two dimensional waves with said extracted two dimensional waves; and

(c) responsive to a result of said comparison, calculating at least one of a plurality of linear coordinate transformations, said plurality of linear coordinate transformations including a scaling factor, a rotational angle, an inversion, an anisotropic scaling factor, and a parallel translation'"'"'s amount, applied to the image.

17. The method of claim 16 further comprising the steps of:

(d) geometrically correcting said image by using said calculated linear coordinate transformation; and

(e) extracting digital watermarks from said image that has been subject to said geometrical correction.

18. A medium for storing a program that is adapted for embedding two dimensional waves in an image to identify at least one geometrical transformation which has been applied to the image, wherein the program comprises:

(a) a function for storing the image into a storage means;

(b) a function for generating and storing at least one pattern, consisting of a set of asymmetric two dimensional waves, into the storage means; and

(c) a function for embedding said pattern comprising a set of asymmetric two dimensional waves in said stored image in a real domain.

19. The medium of claim 18 wherein said program further comprises a function for additionally embedding digital watermarks in said image that has said pattern embedded therein.

20. A medium for storing a program that is adapted for extracting two dimensional waves from an image that has said two dimensional waves embedded therein to identify at least one geometrical transformation which has been applied to the image, wherein the program comprises:

(a) a function for identifying and extracting said two dimensional waves embedded in said image that is stored in a storage means, said two dimensional waves identifying at least one geometrical transformation which has been applied to the image;

(b) a function for comparing predetermined asymmetric two dimensional waves with said extracted two dimensional waves; and

(c) a function, responsive to a result of said comparison, for calculating at least one of a plurality of linear coordinate transformation, said plurality including a scaling factor, a rotational angle, an inversion, an anisotropic scaling factor, and a parallel translation'"'"'s amount, applied to the image.

21. The medium of claim 20 wherein the program further comprises:

(d) a function for geometrically correcting said image by using said calculated linear coordinate transformation; and

(e) a function for extracting digital watermarks from said image that has been subjected to said geometrical correction.