Digital anti-counterfeiting software method and apparatus

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DIGITAL ANTI-COUNTERFEITINGSOFTWARE METHOD AND APPARATUS 9375/2 WO 97/20298

PCT/US96/193IQ - 1 -

DIGITAL ANTI-COUNTERFEITING SOFTWARE METHOD AND APPARATUS^flELD OP THE INVENTION

This invention relates generally to a method and apparatus,as implemented by a software program on a computer system, forproducing counterfeit-deterring scrambled or coded indiciaimages, typically in a printed form. This method and system arecapable of combining a source image with a latent image so thelatent image is visible only when viewed through a specialdecoder lens.

BACKGROUND INFORMATION

To prevent unauthorized duplication or alteration ofdocuments, frequently there is special indicia or a backgroundpattern provided for sheet materials such as tickets, checks,currency, and the like. The indicia or background pattern isimposed upon the sheet material usually by some typeof printingprocess such as offset printing, lithography, letterpress orother like mechanical systems, by a variety of photographicmethods, by xeroprinting, and a host of other methods. Thepattern or indicia may be produced with ordinary inks, fromspecial inks which may be magnetic, fluorescent, or the like,from powders which may be baked on, from light sensitivematerials such as silver salts or azo dyes, and the like. Mostof these patterns placed on sheet materials depend uponcomplexity and resolution to avoid ready duplication.Consequently, they add an increment of cost to the sheetmaterial without being fully effective in many instances inproviding the desired protection from unauthorized duplicationor alteration.

Various methods of counterfeit-deterrent strategies havebeen suggested including Moire-inducing line structures,variable-sized dot patterns, latent images, see-throughs, bar-codes, and diffraction based holograms. However, none of thesemethods employs a true scrambled image or the added securitybenefits deriving therefrom. SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 2 -

This same inventor earlier disclosed a novel system forCoding and decoding indicia on printed matter by producing aparallax panoramagram image. These principles and embodimentsof U.S. Patent No. 3,937,565, issued February 10, 1976 arehereby incorporated by reference. The indicia were preferablyproduced photographically using a lenticular line screen (i.e.a lenticular screen) with a known spatial lens density (e.g. 69lines per inch). A specialized auto-stereoscopic camera mightbe used to produce the parallax image such as the one describedin this inventor's U.S. Patent No. 3,524,395, issued August 18,1970, and U.S. Patent No. 3,769,890, issued November 6, 1973.

Photographic, or analog, production of coded indicia imageshas the drawback of requiring a specialized· camera. Also, theanalog images are limited in their versatility in that an areaof scrambled indicia is generally noticeable when surrounded bynon-scrambled images. Also, it is difficult to combine severallatent images, with potentially different scrambling parameters,due to the inability to effectively re-expose film segments ingenerating the scrambled, photographic image.

Accordingly, a method and apparatus are needed whereby thephotographic process and its results are essentially simulateddigitally via a computer system and related software.Additionally, a system is needed whereby scrambled latent imagescan be integrated into a source image, or individual colorcomponents thereof, so that the source image is visible to theunaided eye and the latent image is visible only upon decoding.Also needed is the ability to incorporate multiple latentimages, representing different "phases", into the source imagefor added security.

SUMMARY OF THE INVENTION

The present invention provides a software method andapparatus for digitally scrambling and incorporating latentimages into a source image. The latent image -- in digitizedform -- can be scrambled for decoding by a variety of lenticularlenses as selected by the user, with each lens having differentoptical properties such as different line densities per inch, SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/I9310 - 3 - ^nd/or a different radius of curvature Lor the lenticulas.different degrees of scrambling might also be; selected whereinthe latent image is divided up into a higher multiplicity oflines or elements. For decoding purposes, the multiplicity ofelements would be a function of the lens density.

The source image is then rasterized, or divided up into aseries of lines equal in number to the lines making up thescrambled latent images. Generally, when hard copy images areprinted, the image is made up of a series of "printers dots"which vary in density according to the colors found in thevarious component parts of the image. The software method andapparatus of the present invention, takes the rasterized linesof the source image and reforms them into the same generalpattern as the lines of the scrambled latent image. Hence,where the source image is darker, the scrambled lines, are formedproportionately thicker; where the source image is lighter, thescrambled lines are formed proportionately thinner. Theresulting combined image appears to the unaided eye .like theoriginal source image. However, since the component rasterizedlines are formed in the coded pattern of the scrambled latentimage, a decoder will reveal the underlying latent image. Dueto the high printing resolution needed for such complexscrambled lines, attempts to copy the printed image byelectromechanical means, or otherwise, are most oftenunsuccessful in reproducing the underlying latent image.

As a result of this digital approach, several differentlatent images can be scrambled and combined into an overalllatent image, which can then be reformed into the rasterizedsource image. This is achieved by dividing the rasterized linesinto the appropriate number of images (or phases) andinterlacing the phased images in each raster line element. Eachindividual latent image might be oriented at any angle andscrambled to a different degree, so long as the scrambling ofeach image is a functional multiple of the known decoderfrequency. Alternatively, the grey scale source image might bedivided up into primary component printing colors (e.g. cyan, SUBSTITUTE SHEET (RULE 26) WO 97/20298

PCT/US96/1931O - 4 - magenta, yellow, and black, or CMYK; red, green, blue, or RGB).Single color bitmap formats might also be used for certainapplications. A scrambled latent image, or a multi-phasedimage, could then be individually reformed into each componentcolor. Upon rejoining of the colors to form the final sourceimage, the decoder will reveal the different latent imageshidden in the different color segments.

The present invention also allows the option of flippingeach of the elements of the latent image after it 'has beendivided or scrambled into its elemental line parts. As has beendiscovered by the inventor, this unique step produces relativelysharper decoded images when each of the elements is flippedabout its axis by one-hundred and eighty {180) degrees. Thissame effect was achieved by the process of U.S. Patent No.3,937,565, and the cited stereographic cameras therein, throughthe inherent flipping of an object when viewed past the focalpoint of a lens. The flipped elemental lines are then reformedinto the rasterized source image. While enhancing the sharpnessof the latent image, the flipping of the elements has noadverse, or even noticeable, effect on the appearance of thefinal coded source image. Moreover, by combining two imagesconsisting of one image where the elements are flipped andanother where they are not flipped, the appearance of a spatialseparation of the two images will occur upon decoding.

As needed, the source image might simply consist of a solidcolor tint or a textured background which would contain hiddenlatent images when viewed through the proper decoder. Suchsolid, tinted areas might frequently be found on checks,currency, tickets, etc.

Other useful applications might include the latent encodingof a person's signature inside a source image consisting of thatperson's photograph. Such a technique would make it virtuallyimpossible to produce fake ID's or driver's licenses through thecommon technique of replacing an existing picture with a falseone. Other vital information besides the person's signature SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/I9310 - 5 - (e.g. height, weight, identification number, etc.) might also beincluded in the latent image for encoding into the source image.* Still other useful applications might include, for example,the following: credit cards, passports, photo-identificationcards, currency, special event tickets, stocks and bondcertificates, bank and travelers checks, anti-counterfeitinglabels (e.g. for designer clothes, drugs, liquors, video tapes,audio CD's, cosmetics, machine parts, and pharmaceuticals) , taxand postage stamps, birth certificates, vehicle restorationcards, land deed titles, and visas.

Thus, an objective of the present invention is to providea counterfeit-deterrent method and apparatus, as implemented bya software program on a computer system, for producing scrambledor coded indicia images, typically in a printed form. The codedimage can then be decoded and viewed through a special lenswhich is matched to the software coding process parameters. A further objective of the present invention is to providea counterfeit-deterrent method and apparatus, as implemented bya software program on a computer system, wherein a source imageis rasterized, and the latent image is broken up' intocorresponding elemental lines, and the rasterized source imageis reconstructed according to the coded pattern of the scrambledimage.

Yet a further objective of the present invention is toprovide a counterfeit-deterrent method and apparatus, asimplemented by a software program on a computer system, whereinthe source image is converted into a grey scale image forincorporation of a latent scrambled image.

Still another objective of the present invention is toprovide a counterfeit-deterrent method and apparatus, asimplemented by a software program on a computer system, whereinthe grey scale source image is further separated out into itscomponent color parts for possible incorporation of latentscrambled images into each component color part, with the partsbeing rejoined to form the final encoded source image. SUBSTITUTE SHEET (RULE 26) - 6 - A related objective of the present invention is to providea counterfeit-deterrent method and apparatus, as implemented bysoftware program on a computer system, wherein the elementallines of the scrambled image may be rotated or flipped about their axis as necessary, or as selected by the user. A further objective of the present invention is to providea counterfeit-deterrent method and apparatus, as implemented bya software program on a computer system, wherein the "singlephased" the scrambled image consists of a first latent imagewhich has been sliced and scrambled as a function of a userselected decoder density and scrambling factor.

Yet another objective of the present invention is toprovide a counterfeit-deterrent method and apparatus, asimplemented by a software program on a computer system, whereinthe "two phased" scrambled image is sliced as a function of auser selected decoder density, and each slice is halved into twosub-slices, and the first and second latent images arealternately interlaced in the sub-slices, with each latent imagescrambled by a user selected scrambling factor.

Still another objective of the present invention is toprovide a counterfeit-deterrent method and apparatus, asimplemented by a software program on a computer system, whereinthe "three phased" scrambled image is sliced as a function of auser selected decoder density, and each slice is divided intothree sub-slices, and the first, second, and third latent imagesare alternately interlaced in the sub-slices, with each latentimage scrambled by a user selected scrambling factor.

Yet another objective of the present invention is toprovide a counterfeit-deterrent method and apparatus, asimplemented by a software program on a computer system, whereinan "indicia tint" is produced which is similar to a two phasedSI, but with one source file, and every second sub-slice of theinput image is the complimenter of the first sub-slice. SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 7 - A further objective of the present invention is to providecounterfeit-deterrent method and apparatus, as implemented bya software program on a computer system, wherein the sourceimage consists of a solid color or tint pattern with thescrambled image incorporated therein, but the elemental linesare flipped only where a letter or object occurs in underlying latent image.

Still another objective of the present invention is toprovide a counterfeit-deterrent method and apparatus, asimplemented by a software program on a computer system, whereinthe latent image is encoded directly into a certain visiblefigure on the source image, thus creating a "hidden image"effect.

Yet another objective of the present invention is toprovide a counterfeit-deterrent method and apparatus, asimplemented by a software program on a computer system, whereina bitmap source image is used (instead of a grey scale, image) tocreate hidden images behind single color source images orsections of source images.

Still another related objective of the present invention isto provide a counterfeit-deterrent method and apparatus, asimplemented by a software program on a computer system, whereina multilevel, 3-dimensional relief effect is created by applyingdifferent scrambling parameters to an image and its background.

Another related objective of the present invention is toprovide a counterfeit-deterrent method and apparatus, asimplemented by a software program on a computer system, wherein"void tint" sections might be produced and the word "void," orsimilar such words, would appear across documents if attemptsare made to photocopy them.

Yet another possible objective of the present invention isto use the software program and computer system to produce theequivalent of "water marks" on paper products. SUBSTITUTE SHEET (RULE 23) WO 97/20298

PCT/O596/I!«IU - 8 -

Still another possible objective of the present inventionis to use the software program and computer system to produce,or to aid in producing, holographic images through linediffraction techniques.

Other objectives and advantages of this invention willbecome apparent from the following description taken inconjunction with the accompanying drawings wherein are setforth, by way of illustration and example, certain embodimentsof this invention. The drawings constitute a part of thisspecification and include exemplary embodiments of the presentinvention and illustrate various objects and features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a "one phase" example of the ScrambledIndicia (SI) process wherein an output image is sliced intoelements as a function of the frequency of the decoding lens andthe scrambling factor (or zoom factor, or base code) as selectedby the user.

Figure 2(a) shows a scrambled "P" (above) with itsresulting elements enlarged 400% (below) wherein the elementshave been flipped 180 degrees about their vertical axes.

Figure 2(b) shows the scrambled "P" (above) of Figure 9(a)with its resulting elements enlarged 400% (below) wherein theelements have not been flipped or altered.

Figure 3 shows a "two phase" SI example of slicing theoutput image, wherein the width of the slice is one half of theone phase example, with every odd slice being from a 'sourceone' file, and every even slice being from a 'source two' file.

Figure 4 shows a "three phase" SI example of slicing theoutput image, wherein the width of the slice is one third of theone phase example, with every third slice being from the samesource input file.

Figure 5 shows a comparison of the one, two, and threephase scrambled and coded results. SUBSTITUTE SHEET (RULE 25) WO 97/20298

PCT/US96/1931O - 9 -

Figure 6 shows a series comparison of scrambled images asfunction of increasing lens frequency (or line density per inch) from 10 through 100.

Figure 7 shows a series comparison of scrambled images asa function of increasing zoom factor (or base code) ranging from3 0 through 250, for a given lens frequency.

Figure 8 shows a series comparison of two phased scrambledimages wherein the first latent image and the second latentimage are rotated with respect to each other ranging from 10through 90 degrees.

Figure 9 shows the steps involved to encode, as hiddenimages, two separate scrambled indicia patterns into twoseparate base colors as extracted from the original sourceimage.

Figure 10 shows a flow chart of the steps relating to theprocess as shown in Figure 9.

Figure ll shows an example hardware configuration forrunning the S.I. software and performing the SI process.

Figure 13 the introductory screen for the scrambled indiciasoftware (SIS).

Figure 14 shows the series of options appearing on thegeneralized screen for a one phase type SI selection.

Figure 14(a) shows the choices resulting from clicking onthe File Menu option.

Figure 14(b) shows the resulting screen when either load orsave is selected from the File Menu option.

Figure 15 shows and details further options of thegeneralized screen for a one phase SI selection.

Figure 15(a) shows the Browse option screen as selectedfrom the screen shown in Figure 15.

Figure 16 shows the generalized screen for a two phase typeSI selection.

Figure 17 shows the generalized screen for a three phasetype SI selection.

Figure 18 shows the generalized screen for an indicia tinttype SI selection. SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 10 -

Figure 18{a) shows an "indicia tint" example of slicing the^output image, wherein the width of the slice is one half of theone phase example, with every other sub-slice being the complimenter of the previous sub-slice input.

Figure 19 shows the generalized screen for a hidden imagetype SI selection.

Figure 20 shows the generalized screen for a multileveltype SI selection.

Figure 21 shows the generalized screen for an S.I. Rastertype selection.

Figure 22 shows examples of rastering techniques with theaccompanying circles indicating an enlarged view of a portion ofthe overall pattern. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT .....

Although the invention has been described in terms' aspecific embodiment with certain alternatives, it will bereadily apparent to those skilled in this art that variousmodifications, rearrangements and substitutions can be madewithout departing from the spirit of the invention. The scopeof the invention is defined by the claims appended hereto.

The Scrambled Indicia (SI) process involves rasterizing, ordividing up into lines, a source or visible image according tothe frequency (or density) of a lenticular decoder lens. Thenumber of lines is also a function of the scrambling factor, orzoom factor, as applied to a latent or secondary image. Afterthe latent image is processed and scrambled, a set of scrambledlines exists which can then be combined into the rasterizedlines of the visible image. The visible image is thus reformed,or re-rasterized, according to the pattern of the scrambledlatent image lines. Where the visible image is darker, thescrambled lines are made proportionately thicker in re-formingthe rasterized lines of the visible image; similarly, where thevisible image is lighter, the scrambled lines are madeproportionately thinner. As a result, a new visible image is SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 11 - created, but with the encoded, latent, SI pattern being visible^underneath" when viewed through a transparent decoder lens.

Referring now to Figure 1, certain example details of theprocess are shown. In this example, one latent image isprocessed into a visible source image, and this process isgenerally referred to as a "one phase" SI operation. In any SIoperation, an output image is a function of the decoder lensdensity. An output image 2 is shown which is sliced up intoelemental slices, or segments, of width h. (See reference 4).Each slice width h is a function of several factors such asdensity and base code.

As for lens density, the inventor has assigned referencenames to lenses with various frequencies (or line densities perinch), including for instance, the following: D-7X with 177lines/inch; D-7 with 1S2.5 lines/inch; D-6 with 134-lines/inch;D-9 with 69 lines/inch. (See reference 6). The software forperforming this process also provides an "x2" (or doublingfactor, df) option which doubles the effective line density, andhence divides the output image up into twice as many slices.The resulting SI image will still be decodable by the selectedlens because the number of lines is an even multiple of thefrequency of the lens.

The output image slice, having width h, is processed as a function of the input slice width i (see reference 8). In turn, width i is a function of width h, the lens density, and a base code factor (or scrambling factor) as selected by the user.

These formulas are as follows: df = 2 (if "x2" selected); 1 (by default)o = h*density/100 (See reference 10)i = o*base code(B) (See reference 8)

Rearranging these formulas, the value for h becomes: (l/B)*100h -------------

Density*df SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 -12 --

Hence, as the value for the 'base code and/or the density isΦ increased, the width h will decrease. A larger base code, orscrambling factor, therefore creates more lines and results in a more distorted or scrambled image.

Additionally, the SI process allows the option of flipping12 the input slice to affect the sharpness of the image.Referring now to Figure 2(a), the letter "P" is shown scrambled30 according to the S.I. process. An image 34 enlarge by 400%further shows the characteristic elements 38. In this instancethe elements have each been individually flipped 180 degreesabout their vertical axis. Figure 2(b) shows the same example"P" 32, and enlarged version 36 where the elements "have not beenflipped. When viewed through the proper decoder lens for theseparticular S.I. parameters, the flipped "P" will appear sharper,or more visually distinct, than the unflipped "P". For anyscrambled image, the software provides the user the option offlipping or not flipping the elements, as further detailedbelow.

Referring now to Figure 3, a "two phase" SI process isshown whereby the method is similar to that for the one phaseSI. in this case, however, each slice of width h is furtherdivided into a first and second sub-slice. The elemental linesof first and second scrambled images will be stored by thesoftware program in 'source one' and 'source two' files. In theresulting output image, the odd slices 14 are composed ofelemental lines from the source one file, and the even slices 16 SUBSTITUTE SHEET (RULE 26) wo 97/20298 PCT/US96/19310 - 13 - are from the source two file. Upon decoding, the first andsecond scrambled images will appear independently discernable.

Referring now to Figure 4, a "three phase" SI process isshown as similar to the one and two phase SI processes. In thiscase, width h is divided into three parts. The first, second,and third scrambled images are stored in three computer sourcefiles. In the resulting output image, every third slice 18, 20,and 22 comes from the same respective first, second, Or thirdsource file. Again upon decoding, the first, second, and thirdscrambled images will appear independently discernable.Referring to Figure 5, a comparison is shown of the one, two,and three phase scrambled results for a given lens" density andbase code. Figure 6 shows a comparison of the scrambled resultsfor a given base code and a varying set of lens densitiesranging from 10 through 100 lines per inch. As the lens densityincreases, the relatively width of each elemental line decreasesand causes the scrambled image to be harder to discern. InFigure 7, the lens density is fixed while the zoom factor, orbase code, is increased through a series of values ranging from30 - 250. Similarly as per the formulas above, as the base codeis increased, the relative width of each elemental linedecreases and causes the scrambled image to be harder todiscern. As shown, the discernability of the scrambled imagefor a zoom factor of 30 is far greater than for a zoom factor of250. SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 14 - .

Another benefit or feature of multiple phasing is that each^Latent image can be oriented at a different angle for addedsecurity. Referring now to Figure 8, a series of two phaseimages is shown where the first latent image remains fixed andthe second latent image is rotated, relative to the first image,through a series of angles ranging from 10 - 90 degrees.

Referring now to Figure 9, an example of the versatilityoffered by a software version of the S.I. process is shown. Inthis example, a postage stamp is created whereby the S.I.process incorporates two different latent images, oriented 90degrees to each other, into two different base colors of thevisible source image. The visible source image -- as comprisedof its original RGB colors -- is scanned, as a digital highresolution image, into a program such as ADOBE PHOTOSHOP. Theimage is then divided into its component color "plates" in yetanother commonly used color format CMYK, wherein the componentimages of Cyan 42, Magenta 44, Yellow 46, and Black 4 8 areshown. The versatility of the S.I. software allows for the easycombination of a latent S.I. image with any one component colorof the visible image. In this case, the latent invisible image50 with the repeated symbol USPS is scrambled and merged withthe Cyan color plate 42. The resulting Cyan color plate 52 --as described above -- will show the original visible image in arasterized pattern to the unaided eye, but the latent invisibleimage will be encoded into the rasterized pattern. A secondlatent invisible image 54 with the repeated trademark SCRAMBLEDINDICIA (of this inventor) is merged with the Magenta color SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 15 - plate 44 to produce the encoded Magenta image 56. The finalφ visible image (similar to 40) will then be re-composed using theoriginal Yellow and Black plates along with the encoded Cyan and

Magenta plates.

Referring now to Figure 10, an example flow chart of thesteps performed by the S.I. software in Figure 10 are shown.The source image is first digitized 41 and then divided out intoits component CMYK colors 43. Each color plate 45, 47, 49, and51 can be independently operated on by any of the S.I. processimplemented. In this case, a hidden image technique (orrasterization in single color) is performed. The target colorplates are rasterized 53, 55 and the S.I. scrambling process isapplied to the first latent image 57 and the second latent image 59. The first scrambled image is then merged with therasterized Cyan color plate 61 and the second scrambled image is ' merged with the rasterized Magenta color plate 63. The finaloutput image is a created by re-joining the encoded Cyan andMagenta color plates with the unaltered Yellow and Black colorplates 65. In this example, only the Cyan and Magenta colorswere encoded. Other examples‘might choose to encode one color,three colors, or all four colors.

While this process might be implemented on any computersystem, the preferred embodiment uses a setup as shown in Figure 11. Various image files, as stored in "tif" format 60, are fedinto a SILICON GRAPHICS INC. (SGI) workstation 62 which runs the S.I. software. While the software might run on any computercapable of handling high resolution graphics, the SGI machine is SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 16 - used because of its superior speed and graphical abilities. The^files are opened by the S.I. software and the scrambled indicia types, values, and parameters are set by the program user 64.Encoding algorithms are applied by the S.I. software to mergelatent images with visible images to create a new scrambled"tif" file 66. The new "tif" file is then fed into a MACINTOSHcomputer 68 for implementation into the final design program,wherein the file is converted into an Encapsulated PostScript(EPS) file format 70. The finished design is then sent to anoutput device of choice 72 which is capable of printing thefinal image with the resolution necessary to maintain and revealthe hidden latent images upon decoding. The preferred outputdevice is manufactured by SCITEX DOLVE.

Referring now to Figure 12, a flow chart of the overalloperation of the S.I. Software is shown. Upon entering theprogram 80, a set of interface settings are either created 82,or read 86 from a default file 84. The user is then presentedwith a series of input screens for selecting the type of S.I.process to perform, along with the related parameters forperforming such an operation. One option might be to save thesettings already selected 90 into a user selected file 92. Arelated option would be to load settings already saved 94 intoa user selected file 96.

As already described, the user might choose to perform aone, two, or three phase S.I. process. Accordingly, the userwould indicate the appropriate source files on which to performthe S.I. process and indicate that such a one, two, or three SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 17 - phase calculation (shown as 98, 100, and 102) should be^performed. Other S.I. operations which could be selected forcalculation, would include a "tint" method 104, a "hidden"method 106, a "multilevel" method 108, and a "raster" method110. Otherwise, the user might choose to exit the program 112,or re-enter the selection process 114.

Upon transitioning past the selection process, the programchecks 166-128 the various input settings selected the user.The program detects errors 117-129 relating to each selection,and displays an appropriate error message 131 as appropriate.Based upon the input settings selected, the various operationswill be performed, e.g. scramble with one phase method 130 andsave the one phase results to an output file 132; scramble withtwo phase method 134 and save the two phase results to an outputfile 136; scramble with three phase method and save the threephase results to an output file 140; scramble with tint method142 and save the tint method results to an output file 144;scramble with hidden method 146 and save the hidden results toan output file 148; scramble with multilevel method 150 andsave the multilevel results to an output file 152; or scramblewith raster method 154 and save the raster results into anoutput file 156. The results of any of these methods can thenbe displayed and viewed 160 (if desired) via a resulting viewerwindow 162. Tonal sound indicators 166 can also indicate theprogress of the software if selected 164. SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 18 -

The S.I. software uses a variety of user interface screens^zhich facilitates choosing which type of S.I. process will beperformed, and under which parametric conditions. Figure 13shows the introductory screen upon entering the SIS programwhich shows the user the ownership rights associated with theprogram. The user interface for the SIS is based upon the "Xwindow" environment. It is similar to most GUI (Graphical UserInterfaces) . When the user moves the mouse pointer to a choicefield and holds the mouse button down, the user will get a popdown or pop up window. This window will allow the user to make even more choices.

Figure 14 shows the basic user interface screen associatedwith performing an SI operation. When the user clicks on theFile Menu option, the choices in Figure 14(a) will appear (e.g.About SIS, Load Settings, Save Settings, Sound, and Quit) . Whenthe user chooses either load or save from the file menu, thescreen in Figure 14(b) will appear. The user may drag theslider bar 200 or click on the arrow keys 201 to move throughthe list of available files. Moreover, the user can use thedirectory bar buttons 202 to shift backwards in the showndirectory hierarchy. The "filter" button 203 brings up anotherwindow 204 which allows the user to specify which type of filesto view; for instance the "wildcard" designator could beused with "*.tif" to bring up all "tif" files for possibleselection from among the listed files. Once the desired file isfound, the "OK" button 205 accepts and loads/saves the file.Either cancel button 206 ends the current operation. SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 19 -

Furthermore, if the user activates the Sound setting, the SISprogram will provide verbal cues to let the user know what'agoing on; otherwise, the SIS program will remain silent duringoperation. The user can quit the SIS software at anytime byselecting quit, or executing an Alt-Q keystroke.

Referring again to Figure 14, the "decoder" box 170 showsthe type of decoder selected (e.g. D-7X) . The "type" box showsthe scramble type 176 selected (e.g. one phase S.I., two phase S.I,, hidden image S.I., etc.). The "density" slider bar 172allows the user to control the line weight of the image that iscreated during the encoding process. The feature will affectboth the "positive" (darkened) and "negative" (white) space ofthe object being encoded. This value can be adjusted based uponwhat you are encoding and what the final print destination willbe. The "base code" slider bar 174 allows the user to controlthe amount of scramble that is applied during the encodingstage, as described above. The "flip" box allows the user toturn each individual scrambled element by 180 degrees about itsvertical axis. This option helps hide the original item whenthat item is of a simple enough nature to see even after thescramble. In other words, sometimes when scrambling a singleword or a few characters, the letters are still discernabledespite the scrambling process applied. By flipping theelements, a deeper scramble can often be achieved which canstill be decoded by the same lens. Also, as mentioned before,flipping the elements often produces a sharper decodedcharacter. SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/I9310 - 20 -

Figure 15 shows the same basic user interface screen withfurther explanations of user interface boxes. The "source file"box 178 allows the user to directly enter the file name to whichthe program is applying the scramble. The "destination file"box 180 allows the user to directly enter the name of the filefor the finished output. Both the source file and destinationfile boxes have "browse" buttons 182 which pull up yet anotherbox 184 (Figure 15(a)) for selecting possible source anddestination files. In the browse box, the user may use arrows,or the slider bar, to scroll through the file directories andlocate and select a particular file. The "filter" box 185allows the user to select a specific file name arid have theprogram search for it. The "resolution" box 186 indicates theresolution of the final output image. This number should bematched to the resolution of the destination printing device.The "view" option box 188 allows the user to decide whether ornot to see the scrambled image upon completion of the S.I.calculation. The "LZW" option box 190 allows the user to savefiles using compression. Compression keeps the overall size ofthe files smaller and conserves disk storage space. The"calculate" button 192 allows the user to click on this bar whenready to finally apply the S.I. scrambling process.

Figure 16 shows a similar screen for performing a two phase S.I. operation. However, this screen provides entry boxes fortwo source files 210, where the latent images are interlacedinto a two phased scrambled image. With the two phased example,the user can select a different base code for each image. This SUBSTITUTE SHEET (RULE 261 WO 97/20298 PCT/US96/19310 - 21 - is especially useful when the user wants to create an overlay of^two different sets of text that will be viewed together, yet beseen as separate words when decoded. A "restraint" option box 212 is provided for linking the first and second images togetherwhereby the same base code will be applied to each image. Theremainder of the options are similar to those described above.

Figure 17 shows a similar screen for performing a threephase S.I. operation. This screen provides three source fileinput boxes 214 wherein each input image can have a differentbase code applied, or the same base code can be applied to allby activating the restraint option 216.

Referring now to Figure IB the interface "screen forperforming an "indicia tint" operation is shown. Unlike thehidden image S.I. (below), the indicia tint will flow assmoothly as possible through the image, ignoring tonalvariations. This image might be thought of as a "monotonescramble." Referring now to Figure 18(a), an output image isshown (similar to Figure 2) which is similar to a two phase S.I., but with only one input file. In this instance, everysecond sub-slice 222, 224 of the output image is the complimenter of the immediate previous input sub-slice. Thecomplimenter means, for example, that when the input is black,the complimenter is white, if the input is red, the complimenteris cyan, etc. SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 22 -

Figure 19 shows the interface screen for a "hidden image"^S.I. operation which provides input boxes for a latent image 218and a visible image 220. This operation allows the user to mixtwo images together where one of the images becomes latent tothe other which is visible. This effect will allow the latentimage to be visible only when viewed through the decoder.Hidden image S.I. also allows use of an additional file tocompensate for image offset. The hidden image S.I. is similarto the two phase S.I. (described above) and the indicia tint(below) except that the output background is a picture insteadof white. The first step is to copy the visible image to theoutput image. After this, the method is similar to" the indiciatint, but the density parameter controls the visibility of theimage. Also, the hidden image technique is similar to the S.I.

J

Raster (below), but a bitmap (single color) image is usedinstead of a grey scale image.

Figure 20 shows the user interface screen for multilevel S.I. operation. The multilevel S.I. creates a scrambled imagethat contains a sense of depth perception. This type ofscramble allows the user to set both a minimum base code 226 anda maximum base code 228. This particular version of the SISprogram uses two images, one image called the texture image 222and another called a depth image 224. During encoding, thetonal values of the depth image elements will cause a scramblingvariant in the elements of the texture image. This variant willgive the decoded image the illusion of depth, hence the namemultilevel S.I. SUBSTITUTE SHEET (RULE 26) WO 97/20298

PCT/US96/193IO - 23 -

For example, thia multilevel technique can simulate a 3-liimensional ("3-D") camera effect by placing a face in the depthimage and applying less base code, while flipping the elementsfor added sharpness. The background would be placed in thetexture file which would have more base code applied for morescrambling effect, and with no flipping of the elements. Bysuperimposing these two scrambled images upon each other, thedecoded face would appear to be sharper and have more depth thanthe surrounding background. Hence the face would appear to"float", thereby creating a 3-D effect.

Referring now to Figure 21, the interface screen for an S.I. Raster operation is shown. The S.I. Raster allows the userto mix two images together where one of the images becomeslatent 230 to the other which is visible 232. The latent imagewill interlace with the visible image following the grey scalevalues of that image. This effect will allow the latent imageto be visible only when viewed through a decoder. Additionally,the latent image might consist of a one, two, or three multi-phased image as created using previous interface screens formulti-phased images and saved in an appropriate file.

One of the most useful applications for the S.I. Rasteringtechnique is where the visible image is a photograph and thelatent image might be a signature of that person. Using the SISprogram, the visible image can be rasterized and then thesignature image can be scrambled and merged into the visibleimage raster pattern. The resulting encoded image will be avisible image of a person's photograph, which when decoded will SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 24 - reveal that person's signature. The latent image might includepother vital statistics such as height, weight, etc. This highsecurity encoded image would prove to be extremely useful on such items as passports, licenses, photo ID's, etc.

The processes described above have used line rastering techniques as derived from the suggested lenticular structure ofthe decoding lens. Other rastering techniques might also beused, which would be accompanied by corresponding decoder lensescapable of decoding such rastered and scrambled patterns.Referring now to Figure 22, a series of example rasteringtechniques are shown which could similarly be used to encodescrambled images into rasterized visible source images.Accompanying each type of rastering is a circle showing anenlarged portion of the raster. The example types include:double line thickness modulation; line thickness modulation II;emboss line rastering; relief; double relief; emboss roundraster; cross raster; latent round raster; oval raster; andcross line raster. Another technique, cross embossed rastering,might use one frequency of lens density on the vertical planeand yet another frequency on the horizontal plane. The userwould then check each latent image by rotating the lens. Yetanother technique would include lenses which varying infrequency and/or refractive characteristics across the face ofa single lens. Hence different parts of the printed mattercould be encoded at different frequencies and still be decodedby a single lens for convenience. Undoubtedly many other SUBSTITUTE SHEET (RULE 26) WO 97/20298 PCT/US96/19310 - 25 - rastering types exist which are easily adaptable to the SIS^^encoding techniques.

Regardless of the type of rastering used, a variety ofother security measures could be performed using the SIS programand the underlying principles involved. For instance, theconsecutive numbering system found on tickets or money might bescrambled to insure further security against copying. The SISprogram might also digitally generate scrambled bar encoding.A Method and Apparatus For Scrambling and Unscrambling Bar CodeSymbols has been earlier described in this inventors U.S. Patent4,914,700, the principles of which are hereby incorporated byreference. -.. ·

Yet another common security printing technique includesusing complex printed lines, borders, guilloches, and/or buttonswhich are difficult to forge or electronically reproduce. TheSIS program can introduce scrambled patterns which followcertain lines on the printed matter, hence the inventor refersto this technique as Scrambled Micro Lines.

The security of the Scrambled Indicia might be furtherenhanced by making 3 color separations in Cyan, Magenta, andYellow of the image after the S.I. process has been performed.These colors would then be adjusted to each other so that anatural grey could be obtained on the printed sheet when thecolors are recombined. The inventor refers to this process as"grey match." Hence, while the printed image would appear greyto the unaided eye, the decoded image would appear in color.The adjustment of the separations to maintain a neutral grey SUBSTITUTE SHEET (RULE 26) WO 97/20298

PCT/US96/1931O - 26 - becomes yet another factor to be controlled when using different^bmbinations of ink, paper, and press. Maintaining thesecombinations adds another level of security to valuable documentand currency.

Still another possible use of the SIS program would be tocreate interference, or void tint, combinations on printedmatter. This technique will conceal certain words, like "void"or "invalid" on items such as concert tickets. If the ticket isphotocopied, the underlying word "void" will appear on the copyand hence render it invalid to a ticket inspector. The SISsoftware would provide an efficient and low cost alternative toproducing such void tint patterns. "J.

The SIS program might also be adapted to produce watermark-type patterns which are typically introduced to paper viapenetrating oil or varnish. Furthermore, the SIS program mightbe applicable to producing holograms via line diffractionmethods. Again, the SIS program would prove to be moreefficient and cost effective for producing such results.

It is to be understood that while I have illustrated anddescribed certain forms of my invention, it is not to be limitedto the specific forms or arrangement of parts herein describeand shown. It will be apparent to those skilled in the art thatvarious changes may be made without departing from the scope ofthe invention and the invention is not to be considered limitedto what is shown in the drawings and described in thespecification. SUBSTITUTE SHEET (RULE 26)