Embedding and reading imperceptible codes on objects

• US 7,044,395 B1
• Filed: 11/30/1999
• Issued: 05/16/2006
• Est. Priority Date: 11/18/1993
• Status: Expired due to Fees

• Current Assignee: Digimarc Corporation
• Original Assignee: Digimarc Corporation
• Inventors: Rhoads, Geoffrey B., Davis, Bruce L.
• Primary Examiner(s): Lee, Michael G.
• Assistant Examiner(s): Franklin, Jamara A.
• Application Number:
  US09/452,021
• Time in Patent Office: 2,359 Days
• Field of Search: 235/487, 235/494, 235/493, 382/100, 382/212, 382/181, 283/72, 283 74- 81, 283 57- 59, 283/93, 283/113
• US Class Current: 235/494
• 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

Abstract

Watermarks and related machine-readable coding techniques are used to embed data within the information content on object surfaces. These techniques may be used as a substitute for (or in combination with) standard machine-readable coding methods such as bar codes, magnetic stripes, etc. As such, the coding techniques extend to many applications, such as linking objects with network resources, retail point of sale applications, object tracking and counting, production control, object sorting, etc. Object message data, including information about the object, machine instructions, or an index, may be hidden in the surface media of the object. An object messaging system includes an embedder and reader. The embedder converts an object message to an object reference, and encodes this reference in a watermarked signal applied to the object. The reader detects the presence of a watermark and decodes the watermark signal to extract the object reference.

Claims

1. A method for embedding a machine readable code on an object, the method comprising:

receiving an object message associated with an object;

converting the object message into an object reference;

encoding at least a part of the object reference in a watermark, including computing the watermark as a function of a signal into which the watermark is embedded and a carrier signal; and

embedding the watermark on the object.

2. The method of claim 1 wherein the object reference includes information about the object.

3. The method of claim 2 wherein the information about the object includes a product identifier.

4. The method of claim 1 wherein the object reference includes one or more machine instructions.

5. The method of claim 4 wherein the one or more machine instructions are executable in response to machine reading of the watermark.

6. The method of claim 1 wherein the watermark is hidden in information content on a surface of the object.

7. The method of claim 6 wherein the watermark is imperceptible to a human upon ordinary scrutiny of the object.

8. A method for embedding a machine readable code on an object, the method comprising:

receiving an object message associated with an object;

converting the object message into an object reference;

encoding at least a part of the object reference in a watermark; and

embedding the watermark on the object;

wherein the object message is encoded in a coding format compatible with a bar code symbology.

9. The method of claim 8 wherein the coding format is a standard UPC coding format.

10. A method for embedding a machine readable code on an object, the method comprising:

receiving an object message associated with an object;

converting the object message into an object reference;

encoding at least a part of the object reference in a watermark; and

embedding the watermark on the object;

wherein the object message is encoded in a coding format compatible with a magnetic stripe coding format.

11. A method for embedding a machine readable code on an object, the method comprising:

receiving an object message associated with an object;

converting the object message into an object reference;

encoding at least a part of the object reference in a watermark; and

embedding the watermark on the object;

including;

encoding at least a first part of the object reference in the watermark and at least a second part in another machine readable code.

12. A method for embedding a machine readable code on an object, the method comprising:

receiving an object message associated with an object;

converting the object message into an object reference;

encoding at least a part of the object reference in a watermark; and

embedding the watermark on the object;

wherein the object reference includes an index to information about the object or an index to one or more machine instructions.

13. The method of claim 12 wherein the object reference includes a reference to one or more machine instructions that are executable in response to machine reading of the watermark.

14. A method for reading a machine readable code on an object, the method comprising:

receiving a data representation of a scan of the object;

processing the data representation to determine whether a watermark is present on a surface of the object;

reading an object reference embedded in the watermark, including decoding the object reference using a carrier signal, wherein the object reference includes information about the object, a machine instruction or set of instructions, or an index to information about the object or an index to a machine instruction or set of instructions.

15. The method of claim 14 wherein the data representation comprises an image.

17. The method of claim 14 including:

using the object reference to look up a product name and price in a retail point of sale transaction.

18. The method of claim 14 wherein the object reference includes a machine instruction or set of instructions that are executed in response to a read operation of the watermark.

16. A method for reading a machine readable code on an object, the method comprising:

receiving a data representation of a scan of the object;

processing the data representation to determine whether a watermark is present on a surface of the object;

reading an object reference embedded in the watermark, wherein the object reference includes information about the object, a machine instruction or set of instructions, or an index to information about the object or an index to a machine instruction or set of instructions;

wherein the data representation represents the surface topology of the object.

19. A product identifier comprising:

an extrinsic standard product code embedded in a watermark, the watermark being embedded in packaging or labeling.

20. The product identifier of claim 19 wherein the watermark is replicated throughout the packaging or labeling to facilitate reading from several different orientations.

21. A method for converting a machine readable code symbology to a watermark coding scheme, the method comprising:

receiving a mapping between product identifiers and codes in the machine readable code symbology;

mapping the product identifiers of a set of products into object references suitable for encoding in watermarks; and

applying the watermarks on the products.