Note: Descriptions are shown in the official language in which they were submitted.
'723
"A SYSrEr~ FOR G}~ KING THE AUTliE~TICITY OF IDENTIFICATION PAPERS"
This invention relates to a system for checking the
authenticity of identification papers.
For the purposes of the present invention, by the term
"system" is meant to indicate the assembly both of the apparatuses
and steps followed for checking the authenticity of an identification
paper.
In the general field for recognizing images, particularly
for recognizing persons, different 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 correspond-
ing to the contours or dots being scanned. This and 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 -tile 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
' - . - ~ -. 1
- l~Q~7Z3
- 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 to prepare
credit cards or such identity papers, the authenticity of which
is hardly verifiab.~!e.
According to one aspect of the invention, there is
provided a method o checking the authenticity of an identific-
ation paper on which is provided an image of a person to beidentified, 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
micro-processor comprising means for determining from said
signals a distribution function of luminance levels against
--2--
147Z3
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,
-2a-
C
47Z3
Fiy. 1 is a schematic block diagram showing the
system according to the invention;
Fig. 2 is a diagram showing the distributing function
for the frequencies of luminance levels in the image of the
identification paper for determining the characteristic
parameters;
Fig. 3 shows the d~agram for the stored frequencies
of the luminance levels as used for calculating the character-
istic 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.
Fig. 5 is a block diagram showing the sampling
frequency control of Fig. 4 in more detail.
A general scheme of the system for checking the
authenticity of identification papers according to the invention
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 var~ous 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.
'
i~4723
Instead of code stored on the paper, storing of said code
could be provided in a suitable separate memory and accordingly
a cross-reference indication of the stored code is provided on
the paper. This second solution 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.
Keeping up in the description of the system shown in Fig. 1,
reference numeral 4 indicates a general apparatus for scanning
said image 2 on the paper whirh, optionally, by adding suitable
filters (not shown) is capable of resolving said paper image 2
into its chromatic components. Said image scanning apparatus 4
ls connected with a sampler 5 providing for separating or
; 15 dividing the image into spots or dots, for each of which a given
vilue 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 half-frame,
is periodically repeated at the frequency of 50 ~z until the
image to be scanned remains in position.
qhe electric signals from television camera ll, corresponding
~ . ~
... . . . .
~lQ47;Z3 "
to a preselected amount 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 trasmission of the
analogical signal by a photomultiplier
l'he 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
per se well known, for example can be of the type marketed as
W HS by DDC and respectively NADC-8 by DDC, thus not requiring
~ any detailed description.
; Is should be noted that the same information appears at
the output of converting circuit 6 as at the output o~ television
, ~ .
camera ll, but now in digital form, instead of analogical.
In the case shown, image dividing and sampling operations
are affected 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 (firtv
half-frames). In order to operate at proper speeds for processor 8
, .
4~23 - 6 -
in use, a plurality of half-frames are used for scanning the
whole image wh;ch, in addition to being divided into trasnverse
lines, is ideally divided into columns perpendicular to said
lines. At each half-frame (total television scanning of tbe
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 hall-frames are used as the columns into
which the image is ldeally divided.
Converting circuit 6 is connected through a control logic 7
to a microprocessor 8, serially supplying thereto the signals
correspondine 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 LSl-11 with
KD-ll and MRV-ll type of storing and programming fittings and
DRV-ll interface.
This microprocessor is also connected to an alpha-numerical
visualizer 9, and a manual control keyboard 10 for inletting
code 3 is connected to the microprocessor through 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 progra~med to serially receive
through control logic 7 the luminance signals of each Or 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.
7 ~
~ re particularly, said microprocessor 8 is program~ed to
generate a function g(li) for the distribution of the
frequencies of the image luminance levels, as shown for ex ~ple
in Fie. 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 this 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.-N8, obtaining on x-l abscissa axis S values, for example
seven values Sl.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 system according to the invention,
or a subsequent scanning for checking the authenticity of the
paper. In the former or in any case where reading of the
~104~3 8 -
characteristic parameters of the image is desired, such parameters
are 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 memo~y.
On the other hand, should the outstanding scanning be
related to the paper authenticity check, or corresponde 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 lO, 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. ~hen the result of said sum is lower than the -threshold
value~ microprocessor 8 emits on visiualizer 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 i5 higher than
the preset threshold value, said microprocessor emi-ts 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
according to the invention 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
}I of horizontal synchronism and signals V of vertical synchronism
7~3 9 _
to a circuit 12 controlling the sampling frequency, shown in
detail in Fig. 5. The sampled signals outputted from circuit 5
are fed to analogical-digital converting circuit 6, then to a
register 13 comprising a set of bistable multivibrators, each
data beingfed therefrom to the inputs of microprocessor 8 at the
time a pulse DR arrives from converter 6.
Sampler 5 is gated by a signal SC having the duration for
a half-frame of telévision 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 ~E of horiæontal 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 tile 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 half-frame, 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 FC 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
~3 10-
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 func-tion of signallling when
frame counter 15 has reached the number correspondig 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
CSR0 from microprocessor 8, causes the output signal of gate
18 to be fed to the input to 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 àrrival of a signal V at an input to gate 18, the
other input of which is at logic level 1 due to signal CSR0,
counter 15 as gated by CSR0 is incremented by one unit;
additionally~ the output of fate 18 in the form of a signal SAC
is supplied to block 20 to prevent the beginning of the image
scannlng at an intermediate location of the half-frame. This
signal SAC gates said block 20 to set at logic level 1 the input
t~ ~
.,~ .
~ 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 CSRl=~, 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 a 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 multivi~rators
by logic signal CSRl=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 0. When microprocessor 8 outputs
signal CSR0, that is when a new data acquisition is started,
block 20 resets its own output REQ B to logic 0.
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 visuPlizer 9. Otherwise, when carrying out the paper
` 20 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 provlded,
and manually through keyboard 10 as hereinafter described.
Through keyboard 10, code 3 is set as read directly on
~ 12 -
'
paper 1, or recalled by suitable external memory. The datQ are
supplied through a data input register 21 to the inputs IN Or
-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 to
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
CSRl is also fed to block 22 comprising a single bistable
multivibrator having a "tristate" output which,at the arrival
of sald signal sets line REQ A to logic level 1, indicating
the presence on register 21 of a data to be withdrawn to
microprocessor o. 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 ou-tstanding
scanning of a checking operation for the paper authenticity,
and the parameters comprising the comparison code. The micro-
processor 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 visualiæer 9.
From the foregoing and as shown on the accompanying
drawings, it is therefore evident that by a system according
to the present invention it would be extremely difficult, if
4~
r
not impossible, to counterfei-t 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 i5 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.
'''
~ .
'
~ '
