Anti-counterfeiting method and apparatus using digital screening

• US 6,104,812 A
• Filed: 01/12/1998
• Issued: 08/15/2000
• Est. Priority Date: 01/12/1998
• Status: Expired due to Term

• Current Assignee: Juratrade Limited
• Original Assignee: Juratrade Limited
• Inventors: Takacs, Ferenc, Koltai, Ferenc, Adam, Bence, Baros, Laszlo
• Primary Examiner(s): Laufer, Pinchus M.
• Application Number:
  US09/005,529
• Time in Patent Office: 946 Days
• Field of Search: 380/51, 380/54, 380/55, 380/10, 380/200, 380/205, 380/243, 380/252, 382/100, 382/115, 382/135, 382/232, 283/17, 283/93, 283/113, 713/176
• US Class Current: 380/51
• CPC Class Codes: G06T 1/0021 Image watermarking
• CPC Class Codes: G06T 2201/0051 Embedding of the watermark in the spatial domain
• CPC Class Codes: G09C 5/00 Ciphering apparatus or methods not provided for in the preceding groups, e.g. involving the concealment or deformation of graphic data such as designs, written or printed messages
• CPC Class Codes: H04N 1/32208 involving changing the magnitude of selected pixels, e.g. overlay of information or super-imposition H04N1/32219, H04N1/32224 take precedence
• CPC Class Codes: H04N 1/32219 involving changing the position of selected pixels, e.g. word shifting, or involving modulating the size of image components, e.g. of characters H04N1/32224 takes precedence
• CPC Class Codes: H04N 1/32251 in multilevel data, e.g. greyscale or continuous tone data
• CPC Class Codes: H04N 1/32309 in colour image data
• 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

Abstract

An apparatus and process for hiding the secondary image within the primary image and generating a high quality hard copy of the unified elemental image of a variety of media. The process comprises the steps of rasterizing the first image into an first elemental image and rasterizing the second image, compensated with its own inverse, into an second elemental image. The first elemental image and the second elemental image are merged into a unified elemental image based on a predetermined decoding and compensating principle, resulting in the second elemental image being hidden within the first elemental image. An output image is created based on the unified elemental image where the primary image is visible to an un-aided eye while the secondary image is hidden from the un-aided eye.

Claims

1. A method as implemented on a computer system for digitally producing encoded screens for incorporating secondary information composed of pixels as an anti-counterfeiting security feature into a visible primary image for use on a document, the method comprising the steps of:

(a) providing a user selected basic screen;

(b) creating an encoded screen from the user selected basic screen and the secondary information by;

(1) using the pixels as digital information carriers,

(2) modifying a parameter of the digital information carriers, and

(3) placing the modified parameter of the digital information carriers within a plurality of color layers of the primary image based on the secondary information,

(c) generating a compensated screen containing the secondary information hidden within by compensating the encoded screen for any distortions;

(d) screening the primary image with the compensated screen to produce a combined output image in accordance with a reproduction technology corresponding to the user selected encoding principle; and

(e) reproducing the document using the reproduction technology, the document incorporating the combined output image.

2. The method of claim 1, wherein the encoded screen is optimally encoded based on a characteristic of a user selected en coding principle.

3. The method of claim 1, further comprising the step of selecting the basic screen according to the reproduction technology used to reproduce the combined output image.

4. The method of claim 1, wherein the step (b) is based on a successive approximation wherein the successive approximation is implemented in a software module executed in a general purpose computer.

5. The method of claim 4, wherein the successive approximation is based upon at least one of a plurality of user defined parameters of the reproduction technology used to reproduce the combined output image.

6. The method of claim 1, wherein said reproducing step is at least one of:

i) printing on a medium,

ii) displaying on a display device, and

iii) storing on a storage medium.

7. The method of claim 1, further comprising the step of reading the secondary information through a decoding device corresponding to the encoding principle.

8. The method of claim 7, wherein the decoding device is at least one of an optical decoder and a user programmable digital decoder.

9. The method of claim 1, wherein the modified parameter of the digital information carriers is based on at least one of:

i) a shape of the pixels,

ii) a size of the pixels,

iii) an angle of the pixels,

iv) a position of the pixels,

v) a frequency of the pixels, and

vi) a density of the pixels.

10. The method of claim 1, wherein the secondary information is at least one of the group consisting of an image, data, printed matter, and bar code.

11. The method of claim 1, wherein the user selected basic screen is one of:

i) a round screen,

ii) a line screen,

iii) an elliptical screen,

iv) a rotogravure screen,

v) a stochastic screen,

vi) a geometric screen,

vii) a continuous tone screen, and

viii) a programmable screen.

12. The method of claim 1, wherein the encoding principle of step (b) is based on a software implementation of a decoding device.

13. The method of claim 1, further comprising the step of optically decoding the combined output image using an optical decoder having an optical filter with at least one of a plurality of geometrical forms.

14. The method of claim 1, further comprising the step of optically decoding the combined output image using an optical decoder having at least one of periodic and random filtering patterns.

15. The method of claim 1, further comprising the step of decoding the combined output image using a complex optical decoder having different optical properties for reading optical codes.

16. The method of claim 15, wherein the different optical properties include at least one of:

i) magnifying,

ii) reversing,

iii) prismatic, and

iv) reducing.

17. The method of claim 1, further comprising the step of electronically decoding the combined output image using an electronic decoder for reading optical codes using a software simulation of at least one function of an optical decoder.

18. The method of claim 1, further comprising the step of electronically decoding the combined output image using an electronic decoder having electronic recognition for reading optical codes.

19. The method of claim 1, wherein the secondary information includes digital codes and, further comprising the step of:

reading the digital codes embedded within the combined output image using a programmable electronic decoder.

20. The method of claim 4, further comprising the step of calculating a high accuracy registration between various color layers of the combined output image for use in a banknote printing apparatus.

21. The method of claim 1, wherein the document is at least one of:

a check,

currency,

a ticket,

a banknote,

a credit card,

a passport,

a photo-identification card,

a special event ticket,

a stock certificate,

a bond certificate,

a bank check,

a travelers check,

an anti-counterfeiting label,

a tax stamp,

a postage stamp,

a birth certificate,

a vehicle registration card,

a deed,

a certificate of title, and

a visa.

22. The method according to claim 1, wherein the visible primary image is a photograph of a person and the secondary information is at least a personal data of the person.

23. The method according to claim 22, wherein the personal data is at least one of i) a height, ii) a weight, iii) an identification number, iv) a signature, v) a blood type, and vi) medical information.