Patent EA-002934-B1 (EA)
Title: Anti-counterfeiting method and apparatus using digital screening
Inventor: KOLTAI FERENC
IPC: G09C5/00
Filed: 1999-01-12
Abstract: 1. A method for encoding a image with a secondary image comprising the steps of: (a) rasterizing the primacy image into a first elemental image; (b) rasterizing the secondary image into a second elemental image; (c) merging the first elemental image and the second elemental image into a unified elemental image based on a predetermined encoding principle; (d) correcting or compensating distortions of the unified elemental image to make the second elemental image invisible within the first elemental image; and (e) producing an output image based on the unified elemental image, the primary image being visible to an un-aided eye and the secondary image being hidden from the un-aided eye. 2. The method of Claim 1, further comprising the step of: (f) viewing the secondary image hidden within the output image by activating a decoding device. 3. The method of Claim 2, wherein, the decoding device is an optical lens corresponding to the predetermined encoding principle. 4. The method according to Claim 1, wherein the secondary image is not present in a copy of the output image. 5. A method as implemented on a computer system for digitally producing encoded screens for incorporating secondary information 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) merging the secondary information and the user selected basic screen based on a user selected encoding principle to an encoded screen; (c) compensating the encoded screen to i) compensate for any distortions in the encoded screen created in the merging step (b) and ii) generate a compensated screen containing the secondary information hidden within the compensated screen, 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. 6. The method of Claim 5, further comprising the step of optimally encoding the encoded screen based on a characteristic of the encoding principle. 7. The method of Claim 5, further comprising the step of selecting the basic screen according to the reproduction technology used to reproduce the combined output image. 8. The method of Claim 5, further comprising the step of encoding the encoded screen using a successive approximation wherein the successive approximation is implemented in a software module executed in a general purpose computer. 9. The method of Claim 8, wherein the successive approximation is based upon at lone of a plurality of user defined parameters of the reproduction technology used to reproduce the combined output image. 10. The method of Claim 5, further comprising the step of reading the secondary information only through a decoding device corresponding to the encoding principle of Step (b). 11. The method of Claim 5, wherein the secondary information is composed of pixels. 12. The method of Claim 10, further comprising the step of using the pixels as digital information carriers. 13. The method of Claim 12, further comprising the step of modifying a parameter of the digital information carriers 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. 14. The method of Claim 13, further comprising the step of placing the modified parameter of the digital information carrier within a single layer of the image. 15. The method of Claim 13, further comprising the step of placing the modified parameter of the digital information carrier within a plurality of color layers of the image. 16. The method of Claim 5, wherein the secondary information is at least one of the group consisting of an image, data, printed matter, and a bar code. 17. The method of Claim 5, 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. 18. The method of Claim 10, wherein the decoding device is at least one of an optical decoder and a uses programmable digital decoder. 19. The method of Claim 5, wherein the encoding principle of step (b) is based an a software implementation of a decoding device. 20. The method of Claim 5, 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. 21. The method of Claim 5, further comprising the step of optically decoding the combined output image using an optical decoder having at least one of periodic and random altering patterns. 22. The method of Claim 5, further comprising the step of decoding the combined output image using a complex optical decoder having different optical properties for reading optical codes. 23. The method of Claim 22, wherein the different optical properties include at least one of: i) magnification, ii) reversal, iii) prismatic, and iv) reduction. 24. The method of Claim 5, further comprising the step of electronically decoding the combined output image using as electronic decoder for reading optical codes using a software simulation of at least one function of an optical decoder. 25. The method of Claim 5, further comprising the step of electronically decoding the combined output image using an electronic decoder having electronic recognition for reading optical codes. 26. The method of Claim 5, wherein the secondary information includes digital codes and, further comprising the step of: directly reading the digital codes embedded within the combined output image using a programmable electronic decoder. 27. The method of Claim 5, 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. 28. The method of Claim 5, further comprising the step of reproducing a document using the reproduction technology, the document incorporating the combined output image. 29. The method of Claim 5, wherein the document is at least one of the group comprising: i) a check, ii) currency, iii) a ticket, iv) a banknote, v) a credit card, vi) a passport, vii) a photo-identification card, viii) a special event ticket, ix) a stock certificate, x) a bond certificate, xi) a bank check, xii)a travelers check, xiii) an anti-counterfeiting label, xiv) a tax stamp, xv) a postage stamp, xvi) a birth certificate, xvii) a vehicle registration card, xviii) a deed, xix) a certificate of title, and xx) a visa. 30. The method according to Claim 29, wherein the visible primary image is a photograph of a person and the secondary information is at least a personal data of the person. 31. The method according to Claim 30, wherein the personal data is at least one of the group selected comprising: i) a height, ii) a weight, iii) as identification number, iv) a signature, v) a blood type, vi) and medical information. 31. The method according to Claim 4, wherein the secondary information is not present in a copy of the document.