System and method for hashing digital images

• US 20040025025A1
• Filed: 07/28/2003
• Published: 02/05/2004
• Est. Priority Date: 10/19/1999
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Ramarathnam Venkatesan, Say-Ming William Koon
• Inventors: Venkatesan, Ramarathnam, Koon, Say-Ming William
• Granted Patent: US 7,421,128 B2
• Time in Patent Office: Days
• US Class Current: 713/176
• CPC Class Codes: G06F 16/583 using metadata automatically derived from the content
• 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 2201/0052 Embedding of the watermark in the frequency domain
• CPC Class Codes: G06T 2201/0061 Embedding of the watermark in each block of the image, e.g. segmented watermarking

Abstract

A system has an image store, a digital hashing unit, and a watermark encoder. A digital image hashing unit computes a hash value representative of a digital image in such a manner that visually similar images hash to the same hash value and visually distinct images hash to different values. The hash value is stored in an image hash table and is associated via the table with the original image. This image hash table can be used to index the image storage. A watermark encoder computes a watermark based on the hash value and a secret. Using both values renders the watermark resistant to BORE (Break Once, Run Everywhere) attacks because even if the global watermark secret is discovered, an attacker still needs the hash value of each image to successfully attack the image. The system can be configured to police the Internet to detect pirated copies. The system randomly collects images from remote Web sites and hashes the images using the same hashing function. The system then compares the image hashes to hashes of the original images. If the hashes match, the collected image is suspected as being a copy of the original.

Claims

1. A computer-implemented method for hashing an image, comprising:

receiving an image; and

deriving a single hash value representative of the image such that images that are visually distinct result in hash values that are approximately independent of one another and images that are different but visually similar result in identical hash values.

2. A computer-implemented method as recited in claim 1, further comprising storing the hash value in association with the image.

3. A computer-implemented method as recited in claim 1, further comprising indexing the image using the hash value.

4. A computer-implemented method as recited in claim 1, further comprising comparing the hash value with another hash value derived from another image.

5. A computer-implemented method comprising:

receiving an image;

deriving a hash value representative of the image such that images that are visually distinct result in hash values that are approximately independent of one another and images that are different but visually similar result in identical hash values; and

watermarking the digital image using, in part, the hash value to produce a watermarked image.

6. A computer-implemented hashing method, comprising:

computing a single hash value representative of a digital image such that images that are visually distinct result in hash values that are approximately independent of one another and images that are different but visually similar result in identical hash values; and

storing the hash value in relationship with the digital image.

7. A computer-implemented hashing method, comprising:

computing a hash value representative of a digital image; and

watermarking the digital image with a watermark derived, in part, using the hash value.

8. A system for processing digital images, comprising:

an image hashing unit to compute a single hash value representative of a digital image such that images that are visually distinct result in hash values that are approximately independent of one another and images that are different but visually similar result in identical hash values; and

a storage to hold the hash value.

9. A system for processing digital images as recited in claim 8, further comprising:

a watermark encoder to watermark the digital image using, in part, the hash value to produce a watermarked image.

10. A system for processing digital images as recited in claim 8, further comprising:

an image comparison module to compare the hash value representative of the image with a second hash value representative of a second image to determine whether the images are visually distinct or visually similar.

11. A system for processing digital images, comprising:

an image hashing unit to compute a hash value representative of a digital image such that images that are visually distinct result in hash values that are approximately independent of one another and images that are different but visually similar result in identical hash values; and

a watermark encoder to watermark the digital image using, in part, the hash value to produce a watermarked image.

12. A computer-readable medium having computer-executable instructions, which when executed on a processor, direct a computer to:

compute a single hash value representative of a digital image such that images that are visually distinct result in hash values that are approximately independent of one another and images that are different but visually similar result in identical hash values; and

store the hash value in relationship with the digital image.

13. A computer-readable medium as recited in claim 12, further comprising computer-executable instructions, which when executed on a processor, direct a computer to:

index the digital image using the hash value.

14. A computer-readable medium as recited in claim 12, further comprising computer-executable instructions, which when executed on a processor, direct a computer to:

watermark the digital image using, in part, the hash value to produce a watermarked image.

15. A computer-readable medium as recited in claim 12, further comprising computer-executable instructions, which when executed on a processor, direct a computer to:

compare the hash value with another hash value representative of another image.