Machine-readable information embedded on a document

• US 6,753,977 B2
• Filed: 01/31/2001
• Issued: 06/22/2004
• Est. Priority Date: 01/31/2001
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Hoover, Rick Paul
• Primary Examiner(s): Mehta, Bhavesh M.
• Assistant Examiner(s): AZARIAN, SEYED H
• Application Number:
  US09/773,405
• Publication Number:
  US 20020101597A1
• Time in Patent Office: 1,238 Days
• Field of Search: 382/234, 382/235, 382/242, 382/248, 382/250, 382/112, 382/100, 382/135, 382/137, 382/139, 382/140, 382/232, 382/233, 347/15, 347/14, 347/18, 347/120, 347/129, 347/134, 705/56, 705/54, 705/57, 705/58, 705/62, 705/72, 358/450, 358/540, 358/1.9
• US Class Current: 358/1.9
• CPC Class Codes: B41M 3/14 Security printing securities B42D25/29
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• 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 2201/327 which are undetectable to the naked eye, e.g. embedded codes
• CPC Class Codes: H04N 2201/3271 Printing or stamping

Abstract

Machine-readable information provided on a printed document in the form of printed marks which are not visually perceptible to the human eye. The printed marks are of a combination of sufficiently small size and selected color which renders the printed marks visually imperceptible to the human eye, yet easily detectable by a machine such as a scanner. The printed marks are dispersed across portions of or all of the printed document in selected patterns for encoding information, such as in a bar code, or the information may merely be printed text. The marks representing the information are printed in unused blank space between or surrounding existing text and other images on the printed document thus avoiding the use of any additional surface area of the media.

Claims

1. A method of encoding information on a page of printed text, the method comprising:

providing a first set of data representing a page of text;

identifying allowable encoding locations on the page of text, the allowable encoding locations including unused blank spaces proximate the text;

generating a second set of data representing image elements arranged in a selected pattern corresponding to information to be encoded;

printing the image elements on the page of text, the printed image elements dispersed over selected areas of the page at the allowable encoding locations wherein each printed image element is separated from other printed image elements, each printed image element being of a selected size and color which is imperceptible to the human eye.

2. The method of claim 1 further including the steps of:

combining the first and second sets of data to generate a third set of data representing the page of text modified to include the encoded information; and

utilizing the third set of data to print the modified page of text, the modifications to the page of text being imperceptible to the human eye.

3. The method of claim 2 further including the step of displaying the modified page of text.

4. The method of claim 1 wherein the allowable encoding locations include unused blank spaces between and separating the text.

5. The method of claim 1 wherein identifying allowable encoding locations comprises:

overlaying the page of text with a grid referenced to a predefined point on the page of text;

identifying the allowable encoding locations according to a predefined criteria; and

mapping the allowable encoding locations to the grid.

6. The method of claim 5 wherein the grid comprises a uniform grid.

7. The method of claim 5 wherein the grid comprises a non-uniform grid.

8. The method of claim 5 wherein each of the allowable encoding locations corresponds to a single pixel.

9. The method of claim 5 wherein each of the allowable encoding locations corresponds to a plurality of pixels associated according to a predefined rule.

10. The method of claim 5 wherein each of the allowable encoding locations corresponds to one or more pixels representing the unused blank spaces on the page of text.

11. The method of claim 5 wherein each of the allowable encoding locations corresponds to one or more pixels representing the unused blank spaces between and separating text characters.

12. Apparatus for encoding information on a printed page, comprising:

first input means for providing a first set of digital data representative of printed images on an original page to be modified;

processor means coupled to the input means for identifying allowable encoding locations on the original page, the allowable encoding locations including unused blank spaces between and separating the primed images;

second input means coupled to the processor means for providing a second set of data representing selected information to be encoded on the original page, the processor means combining the first and second sets of data to generate a third set of data representative of the original page modified to include the printed images on the original page and the selected information encoded thereon, when the modified page is printed, the modification to the original page being imperceptible to the human eye.

13. Apparatus as in claim 12 further comprising printer means coupled to the processor means and being controlled by the third set of data to print the modified page, the difference between the modified page and the original page being imperceptible to the human eye.

14. Apparatus as in claim 13 wherein the printer means comprises a color printer.

15. Apparatus as in claim 13 wherein the printer means comprises a printer having a resolution of at least 600 dots per inch.

16. Apparatus as in claim 12 wherein the first input means comprises a seamier for reading printed pages of a document and providing digital data representative of images printed on the document pages.

17. Apparatus as in claim 12 further including memory means coupled to the first and second input means, and to the processor means, the memory means for storing the digital data representative of the printed images on the original page and of the selected information to be encoded.

18. Apparatus as in claim 12 wherein the processor means is operating under computer program control.

19. Apparatus as in claim 12 wherein the second input means comprises a personal computer coupled to the processor means and the first input means, the personal computer including a keyboard enabling a user to provide the selected information for encoding.

20. An article of manufacture comprising a program storage medium having computer readable program code means embodied therein for adapting a computer to encode selected information on a printed page, the computer readable program code means in the article of manufacture including:

computer readable program code means for enabling a computer to identify allowable encoding locations on a page, the allowable encoding locations including unused blank spaces proximate images on the printed page;

computer readable program code means for enabling a computer to generate a first set of data representing printed images on an original document;

computer readable program code means for enabling a computer to generate a second set of data representing selected information to be encoded on the original document; and

computer readable program code means for enabling a computer to combine the first and second sets of data to generate a third set of data representing the original document modified to include the selected information encoded therein, when the modified original document is printed, the modifications to the original document being imperceptible to the human eye.