GB1583090A

GB1583090A - Systems for checking the authenticity of identification papers

Info

Publication number: GB1583090A
Application number: GB4573077A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-11-03
Filing date: 1977-11-03
Publication date: 1981-01-21
Also published as: JPS5468138A; BE860393A; DE2749018A1; IT1074184B; CH627867A5; NL7712159A; CA1104723A; JPS5819111B2; FR2370328B1; FR2370328A1

Abstract

On issuing the document, certain parameters characteristic of the picture (2) affixed thereto are determined, these constituting a code (3) which is stored on the document itself or elsewhere. Whenever the authenticity of the document is to be verified it is necessary to redetermine the said code by constructing a distribution function of the values of brightness of the picture, calculating the integral of the said function and, by subdividing the said integrated function along the ordinate axis into X equal parts, obtaining on the abscissa axis (X-1) values representing the characteristic parameters of the picture. A comparison with the previously determined code is performed next. The apparatus for carrying out this process comprises a device (4) able to register the picture, a device (10, 11) for inputting the comparison code, a device (5, 6, 7) for converting the signals provided by the picture-registering device into digital values and a microcomputer (8). The process and the apparatus can be used to determine the authenticity of credit cards. <IMAGE>

Description

(54) IMPROVEMENTS IN OR RELATING TO SYSTEMS FOR CHECKING THE AUTHENTICITY OF IDENTIFICATION PAPERS (71) We, MARIO MARCO DE GAS PERI, of Vic. Ciovasso 11, Milan, Italy, of Italian nationality, and MARIA PIERA BONICALZI, of Via Rovere 15, Milan, Italy, of Italian nationality, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a system for checking the authenticity of identification papers.

For the purpose of the present invention, the term "system" is meant to indicate either an apparatus for or method of checking the authenticity of an identification paper.

In the general field of recognizing images, particularly for recognizing persons, differ ent systems have been studied and designed, such systems scanning the image either according to its contours or by dots. In these systems, a possible image identification involves the step of storing a very large amount of data corresponding to the contours or dots being scanned. This and the practical impossibility of having huge storing means or memories, have prevented these systems from being used for normal identification of images and particularly for checking the authenticity of personal identity papers, such as credit cards, papers for recognition of persons within firms, and the like.

To further illustrate the present invention, reference will be had hereinafter to the problem of checking the authenticity of credit cards, or the like, it being understood that the system and apparatus according to the invention could be adopted for checking the authenticity of any identification paper.

It is well known that, to avoid counterfeiting of credit cards, use has been made of special materials and marks. Moreover, to avoid use of credit cards by those who are not regular holders in case of loss or theft, a photo has been applied for visually recognizing a holder at the time of using a credit card.

However, after some accurate exam, even the most complicated systems are liable to counterfeiting and particularly permit preparation of credit cards or such identity papers, the authenticity of which is hardly verifiable.

According to one aspect of the invention, there is provided a method of checking the authenticity of an identification paper on which is provided an image of a person to be identified, the method comprising: determining and storing an image code formed by reading and converting the image to analog signals of luminance corresponding to sampled portions of the image converting the luminance signals from analog to digital value, and determining a distribution function for the luminance level frequencies by accumulating and storing values of the same luminance level and calculating a set of parameters, forming the image code, of a distribution function for the luminance level frequencies; and checking the authenticity of the paper by redetermining the image code, comparing it with the stored previously determined image code, and generating a signal indicating whether the identification paper is authentic based on the comparison.

According to another aspect of the invention, there is provided an apparatus for checking the authenticity of an identification paper on which is provided an image of a person to be identified, comprising a scanning and converting device for scanning the image and producing signals proportional to the levels of luminance of said image, and a microprocessor connected through a control logic circuit to said converting device, said microprocessor comprising means for determining from said signals a distribution function of luminance levels against frequency of the luminance levels and means for integrating or summing said distribution function and dividing it into a number of equal intervals according to frequency to determine a set of typical image parameters from said distribution function, there being further provided a monitoring device for the parameters calculated by the microprocessor and a device for providing coded image parameters to the microprocessor, said microprocessor further comprising means for comparing coded image parameters with said set of typical image parameters and supplying a signal indicative of the result of the comparison.

A preferred system permits not only a visual comparison between the image or photo on the paper and holder, but also a check on the authenticity of the paper.

In a preferred system, an identification paper is used as provided with the image or photo for the person to whom the paper belongs, according to which system provision is made for determining and storing a code of the image comprising characteristic parameters of the image, and identifying by a suitable control apparatus, at the time of paper use, the authenticity of the latter by scanning the image, thereby redetermining the characteristic parameters of the image and comparing the same with the parameters of the stored code, whereupon a signal is emitted in accordance with positive or negative check of the paper.

The invention will be further described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a schematic block diagram showing a preferred system; Fig. 2 is a diagram showing the distributing function for frequencies of luminance levels in an image of an indentification paper for determining characteristic parameters; Fig. 3 is a diagram for the stored frequencies of the luminance levels as used for calculating the characteristic parameters of the function of Fig. 2; and Fig. 4 is a detailed block diagram showing the control portion of the scheme shown in Fig. 3.

A general scheme of a preferred system for checking the authenticity of identification papers is shown in Fig. 1.

In Fig. 1 reference numeral 1 designates a general identification paper which, in addition to the personal data of the person to whom such a paper belongs, such as full particulars and various indications, comprises an image or picture 2, for example an image or picture of the face of he or she who is the holder of the paper. Such an image can be of any form, such as a positive photographic black and white image, but could also be a photographic color image or a transparency, or the like.

In the example shown, paper 1 is also provided with stored code 3 relating to the characteristic parameters. of image 2.

Instead of code stored on the paper, stor ing of said code could be provided in a suit able separate memory and accordingly a cross-reference indication of the stored code is provided on the paper. This second solu tion can be practically useful in cases where the locations at which the document or paper authenticity is checked, and hence a person's identification, are few in number and/or readily connectable with a code storing centre.

Continuing with the description of the sys tem shown in Fig. 1, reference numeral 4 indicates a general apparatus for scanning said image 2 on the paper which, optionally, by adding suitable filters (not shown) is cap able of resolving said paper image 2 into its chromatic components. Said image scanning apparatus 4 is connected to a sampler 5 pro viding for separating or dividing the image into spots or dots, for each of which a given value of an analogical luminance level signal is obtained.

In the specific case, said scanning apparatus is a black and white television camera, in front of which the paper image to be scanned is placed. The television camera takes the image under examination and translates the luminance information into corresponding electric signals. Of course, due to the television camera nature, the complete description of the image, or halfframe, is periodically repeated at the frequency of 50 Hz until the image to be scan ned remains in position.

The electric signals from television camera 4, corresponding to a preselected number of half-frames, are supplied to sampling circuit 5, wherein the image is discreted or divided as above specified.

Instead of said television camera 4 and sampling circuit 5, any image scanning and dividing apparatus could be used, such as a photodiode matrix, or a photodiode bar through a relative movement between the bar and image to be scanned.

Also other systems could be used, for example a flying spot, or scanning by laser emitter and transmission of the analogical signal by a photomultiplier.

The output of sampling circuit 5 is supplied to an analogical/digital converting circuit 6 which in turn is connected to a control logic block 7. Sampling and converting circuits are perse well known and, for example, can be of the type marketed as VVHS by DDC and respectively NADC-8 by DDC, thus not requiring any detailed description.

It should be noted that the same information appears at the output of converting circuit 6 as at the output of television camera 4, but now in digital form, instead of analogical.

In the case shown, image dividing and sampling operations are effected as follows: image 2 is scanned by television camera 4 according to parallel lines transversely of the image. The television camera repeatedly scans the image, when the latter is held stationary, and particularly 50 times a second (fifty half-frames). In order to operate at proper speeds for processor 8 in use, a plurality of half-frames are used for scanning the whole image which, in addition to being divided into transverse lines, is ideally divided into columns perpendicular to said lines. At each half-frame (total television scanning of the image), only one column is scanned, or the signal of illuminance rate is detected on only one spot by line. For the scanning of a whole image, as many halfframes are used as the columns into which the image is ideally divided.

Converting circuit 6 is connected through the control logic 7 to the microprocessor 8, serially supplying thereto the signals corresponding to the illuminance levels of each sampled spot of image 2. Such a microprocessor 8 is, for example, of the 16 bit type marketed by Digital Equipments Corporation as LS1-11 with KD-11 and MRV-11 type of storing and programming fittings and DRV-1 1 interface.

This microprocessor is also connected to an alpha-numerical visualizer or display unit 9, and a manual control keyboard 10 for inputting code 3 is connected to the microprocessor through the control block 7. Alternately to manual inletting of code 3 by keyboard 10, a code reader 11 may be provided, as outlined by dashed lines in Fig. 1.

Microprocessor 8 is suitably programmed to serially receive through control logic 7 the luminance signals of each of the image spots for determining the characteristic parameters of the image. Such a determination is carried out as hereinafter shown with reference to Figs. 2 and 3 of the accompanying drawings.

More particularly, said microprocessor 8 is programmed to generate a function g(li) for the distribution of the frequencies of the image luminance levels, as shown for example in Fig. 2, wherein the frequencies or number N-of spots having the luminance level "li" quoted on the abscissas are given on the coordinates. This microprocessor 8 is also programmed for calculating the characteristic parameters of function g(li) of distribution of the luminance levels of Fig. 2, for example by integrating such a function g(li) as shown in Fig. 3, wherein the integrated function G(li) of the stored up frequencies is shown. On the ordinates of Fig. 3, the number N of spots having a luminance level equal to and lower than luminance level "li" shown on the abscissa axis is indicated.

To calculate the characteristic parameters of the image, function G(li) is divided according to the ordinate axis into X like parts; for example into eight parts, as indicated by No to N8, obtaining on x-l abscissa axis S values, for example seven values S1 to S7 (referred to as "octiles" when dividing into eight parts), neglecting the extreme values. Such values constitute the characteristic parameters of image 2.

It should be discriminated whether the scanning being carried out is the first scanning which is effected in preparing the paper to be used with the preferred system, or a subsequent scanning for checking the authenticity of the paper. In the former or in any case where reading of the characteristic parameters of the image is desired, such parameters are supplied serially for reading thereof from microprocessor 8 to visualizer 9. Such parameters defining said code 3 either are stored on paper 1, or are introduced into a separate memory.

On the other hand, should the outstanding scanning be related to the paper authenticity check, or correspond between photo and stored code, microprocessor 8 compares between the parameters as re-determined from image 2 and the parameters of stored code that has to be deliberately introduced by the operator through keyboard 10, or automatically through code reader 11. For example, the comparison between parameters may be accomplished by adding the squares of the individual differences between corresponding parameters. In turn, the result of this sum is compared in said microprocessor with a predetermined threshold value.

When the result of said sum is lower than the threshold value, microprocessor 8 emits on visualizer 9 a signal of positive check for the authenticity of the paper. On the other hand, when the result of the comparison between the parameters is higher than the preset threshold value, said microprocessor emits still on visualizer 9 a signal of negative check, indicating the non-authenticity of the paper to the operator.

Referring to Figs. 4 and 5, an embodiment of the apparatus will be particularly described.

In Fig. 4, television camera 4 supplies the analogical signal relating to the image to sampler 5, and also supplies signals H of horizontal synchronism and signals V of vertical synchronism to a circuit 12 controlling the sampling frequency, shown in detail in Fig. 5. The sampled signals outputted from circuit 5 are fed to analogic-digital converting circuit 6, then to a register 13 comprising a set of bistable multivibrators, each data being fed therefrom to the inputs of microprocessor 8 whenever a pulse DR arrives from converter 6.

Sampler 5 is gated by a signal SC having the duration of a half-frame of television camera 4, from block 12 controlling the sampling frequency. This block 12 is shown in the detailed scheme of Fig. 5, and comprises a first counter 13 receiving signal H of horizontal synchronism of the television camera and a signal CK of a quartz clock 14, the oscillation period of which defines the number of sampling columns into which the image is ideally divided. Counter 13 counts signals CK and is reset by television camera pulse H at the beginning of each line. Therefore, counter 13 counts for each line the columns into which the image to be scanned is ideally divided.

Block 12 also comprises a second counter 15 which is incremented at each pulse V provided by the television camera at each halfframe, and thus maintains on its outputs the same number for the entire half-frame. The comparison between the outputs of counter 13 and counter 15 is in a first comparator 16, which supplies sampling pulse SC to sampler 5 for gating thereof. The outputs of second counter 15 are fed also to a second comparator 17, which compares the output number from counter 15 with a number corresponding to the image columns number, this number being provided by a set of grounded switches shown at 17'.Comparator 17 accomplishes the function of signalling when frame counter 15 has been reached the number corresponding to the last column of the image division; in this case, the arrival of a signal V of the television camera, concurrently with a signal CSR 0 from microprocessor 8, causes the output signal of gate 18 to be fed to the input of a second gate 19, so that signal FA is supplied to block 20 of Fig. 4, indicating that the image sampling has been completed.

At each arrival of a signal V at an input to gate 18, the other input of which is at logic level 1 due to signal CSR, counter 15 as gated by CSR 0 is incremented by one unit; additionally, the output of gate 18 in the form of a signal SAC is supplied to block 20 to prevent the beginning of the image scanning at an intermediate location of the halfframe. This signal SAC gates said block 20 to set at logic level 1 the input line REQ A to microprocessor 8, signalling the arrival of a valid data from converter 6.

Block 20 of the logic requiring cut off of the data acquisition system comprises bistable multivibrators having a "tristate" output. The bistable multivibrators are gated by the logic signal CSRt = , so that when signal DR arrives from converter 6. a signal is supplied on output REQ A to the corresponding input of microprocessor 8 to signal in the register 13 the presence of a new data to be withdrawn. Correspondingly, at the arrival of signal FA from block 12, gating of the bistable multivibrators by logic signal CSR1 = 0 causes a signal to be supplied on line REQ B to microprocessor 8 to indicate that image scanning has been completed.

Signal REQ B also serves to inhibit further cut off requests on line REQ A until arrival of a novel signal SAC from block 12. At each withdrawal of data from register 13, said microprocessor 8 supplies a signal DT to block 20 resetting line REQ A to logic level . When microprocessor 8 outputs signal CSR , that is when a new data acquisition is started, block 20 resets its own output REQ B to logic .

As above explained, data from counter 13 to microprocessor 8 and relating to luminance level values are processed within the microprocessor for calculating the characteristic parameters of the image (octiles), as specified in connection with Figs. 2 and 3.

Once microprocessor 8 has calculated the characteristic parameters of the image to be scanned and initial coding is being carried out, the data from output OUT of microprocessor 8 are fed onto visualizer 9. Otherwise, when carrying out the paper authenticity check, such parameters are compared with the corresponding parameters as stored in the previously shown manner and that can be introduced into the microprocessor 8 both through code reader 11 of Fig. 1, where the latter is provided, and manually through keyboard 10 as hereinafter described.

Through keyboard 10, code 3 is set as read directly on paper 1, or recalled by suitable external memory. The data are supplied through a data input register 21 to the inputs IN of the microprocessor and stored in a comparison register of the latter. Register 21 comprises a number of bistable multivibrators having a "tristate" output. Said register 21 receives the data from keyboard 10 and supplies such data to the inputs of microprocessor, as above specified, when a signal ST is emitted from keyboard 10 at the end of code setting, and when signal CSR1 from microprocessor 8 is at logic level 1.

Such a signal CSR1 is also fed to block 22 comprising a single bistable multivibrator having a "tristate" output which, at the arrival of said signal sets line REQ A to logic level 1, indicating the presence on register 21 of a data to be withdrawn to microprocessor 8. Line REQ A is reset still by block 22 at the arrival of a signal DT.

Now, the comparison register of microprocessor 8 has therein both the characteristic parameters for the outstanding scanning of a checking operation for the paper authenticity, and the parameters comprising the com- parison code. The microprocessor now provides for a comparison between said parameters, as above specified, and finally emits at output OUT a signal of positive or negative check, which is displayed on visualizer 9.

From the foregoing and as shown on the accompanying drawings, it is therefore evident that, with the preferred system, it would be extremely difficult, if not impossible, to counterfeit any identification paper or use someone else's paper, even after replacement of image 2 on the paper.

The above disclosed system is generally valid independently of how the characteristic image parameters are calculated and the identification code. However, it should be noted that where the determination of the characteristic parameters is accomplished by the system shown in Figs. 2 and 3, due to calculation simplicity and relatively limited number of characteristic parameters required for code determination, while maintaining a very high degree of check safety, use can be made of a checking apparatus of highly reduced overall size and dimensions, and hence of a low cost with capability of a wide diffusion of the system.

WHAT WE CLAIM IS: 1. A method of checking the authenticity of an identification paper on which is provided an image of a person to be identified, the method comprising: determining and storing an image code formed by reading and converting the image to analog signals of luminance corresponding to sampled portions of the image converting the luminance signals from analog to digital value, and determining a distribution function for the luminance level frequencies by accumulating and storing values of the same luminance level, and calculating a set of parameters forming the image code, of a distribution function for the luminance level frequencies; and checking the authenticity of the paper by redetermining the image code, comparing it with the stored previously determined image code, and generating a signal indicating whether the identification paper is authentic based on the comparison.

2. A method as claimed in claim 1, wherein said stored code is stored on the identification paper.

3. A method as claimed in claim 1, wherein said stored code is stored separately from the paper.

4. A method as claimed in claim 1, wherein the characteristic parameters of the stored code are introduced for the comparison through a keyboard.

5. A method as claimed in claim 1, wherein the characteristic parameters of the stored code are automatically introduced for the comparison by direct reading from the identification paper.

6. An apparatus for checking the authenticity of an identification paper on which is provided an image of a person to be identified, comprising a scanning and converting device for scanning the image and producing signals proportional to the levels of luminance of said image, and a microprocessor connected through a control logic circuit to said converting device, said microprocessor comprising means for determining from said signals a distribution function of luminance levels against frequency of the luminance levels and means for integrating or summing said distribution function and dividing it into a number of equal intervals according to the frequency to determine a set of typical image parameters from said distribution function, there being further provided a monitoring device for the parameters calculated by the microprocessor, and a device for providing coded image parameters to the microprocessor, said microprocessor further comprising means for comparing coded image parameters with said set of typical image parameters and supplying a signal, indicative of the result of the comparison.

7. A method of checking the authenticity of an identification paper, substantially as hereinbefore described with reference to the accompanying drawings.

8. An apparatus for checking the authenticity of an identification paper, substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. counterfeit any identification paper or use someone else's paper, even after replacement of image 2 on the paper. The above disclosed system is generally valid independently of how the characteristic image parameters are calculated and the identification code. However, it should be noted that where the determination of the characteristic parameters is accomplished by the system shown in Figs. 2 and 3, due to calculation simplicity and relatively limited number of characteristic parameters required for code determination, while maintaining a very high degree of check safety, use can be made of a checking apparatus of highly reduced overall size and dimensions, and hence of a low cost with capability of a wide diffusion of the system. WHAT WE CLAIM IS:

1. A method of checking the authenticity of an identification paper on which is provided an image of a person to be identified, the method comprising: determining and storing an image code formed by reading and converting the image to analog signals of luminance corresponding to sampled portions of the image converting the luminance signals from analog to digital value, and determining a distribution function for the luminance level frequencies by accumulating and storing values of the same luminance level, and calculating a set of parameters forming the image code, of a distribution function for the luminance level frequencies; and checking the authenticity of the paper by redetermining the image code, comparing it with the stored previously determined image code, and generating a signal indicating whether the identification paper is authentic based on the comparison.