DE1944943A1 - Method and device for coding fingerprints - Google Patents

Description

DR. MÜLLER-BORE DIPL ₁ -INe. 6RALFS Ί g 4 4 9 4 3

DIPL.-PHYS. DR. MANITZ DIPL.-CHEM. DR. DEUFEL

PATENT LAWYERS

^r i Sep. 1969

Mak / Sv - C 2081

C.I.T.-COMPAGNIE INDUSTRIELLE DES TELECOMMUNICATIONS 12, rue de la Baume, Paris 8, France

Procedure and device for coding finger-

Press a "b

In the main application is a device for encoding fingerprints described in the analysis of a cliché having an imprint to be encoded by means of a television camera he follows.

The coding process is essentially based on the marking, or determination of the one at the end of a fingerprint line Points, which are called characteristic points, and on the measurement of the tangent on the fingerprint line on these points. A characteristic point is defined as follows:

a

It is viewed in a plane / area delimited by an angular line; when a point of this line is the apex of an angle is less than 180 °, this point is a singular point. If the area has an extremely elongated shape in has the shape of a line is a singular point that is located at the end of a line, a characteristic point.

The television camera used in the device is equipped with a special scanning system in which a horizontal Band the image by a series of stepped sawtooth pulses and the following band with a new series of

009836 / 1GAÖ

step-shaped sawtooth pulses was analyzed, the second sequence of sawtooth pulses compared to the first in the Height was offset by a fraction of the height of a band.

The object of the present invention is to provide the device Simplify and cheaper, including from a commercially available one TV camera with scanning through normal horizontal lines is made use of, causing differences in the indexing the points and leads in the identification circles.

As in the case of the arrangement according to the main application, the Scanning camera behind a threshold circuit a logical video signal that is either "0" or "1".

According to the invention, a processing memory consisting of N. shift registers, each with Ip digits, is provided which, during a certain time, called the processing time, _{receives the weights of K 2} points and stores which segments on each of N _x , Form lines (or vertical analysis steps, which can have more than one line), the information contained in this processing memory forms a window on the document to be analyzed and this window is lowered by one step after a processing time has elapsed, so that after N A vertical band taken out of the document is scanned with lowering by one step, whereupon the scanning of a subsequent band begins again, which is obtained by lateral displacement by a width approximately equal to a half band, so that the document in its entirety is scanned is covered by M ₂ , bands.

According to an advantageous embodiment of the invention, each logical video signal element runs through all of them in series Tete Eegister, as in the case that the IL were arranged one after the other Register a single shift register *.

Q00 & 36 / 104I

1944343

In a further advantageous embodiment, devices are provided, in a cyclic register with eight digits, the register J is called, the valences of eight digits len, which surround the penultimate position at one end of the middle register of the processing memory, as well as Means to rotate the transferred information in the cyclical register, as well as logical devices to, if necessary to obtain the identification of the penultimate digit as a particular point, namely a singular point corresponding to it.

According to a further special feature, logical devices are provided in order to decide whether a singular point actually is one end of a fingerprint line and thus a characteristic point, and in this case is means provided to store the coordinates of this point as well as the tangent at this point.

Further details and advantages of the invention are provided below explained with reference to the drawing; in this shows:

Figure 1 shows an overview of the entire arrangement,

Figure 2 is a diagram for explanation there? Analysis of the cliché, that bears the fingerprint to be examined,

Figure 5 is a more detailed circuit diagram of the parts F, G, H, J of Fig. 1,

FIG. 4- a graph to explain the mode of operation of certain circles in FIG. 3 ₅

Figure 5 shows a number of configurations which are illustrative serve the functioning of the organ J of Fig. 3,

Figure 6 is a simplified circuit diagram of the sub-arrangements K, M, Ή of Fig. Λ ,

Figure 7 is a simplified circuit diagram of the P and Q sub-assemblies of Fig. 1,

ifigur 8 a representation to explain the geometric meaning a logical condition,

009836/1046

. ^"4 ~ 1944S43

FIG. 9 shows a shape of a course of a fingerprint line which leads to the rejection of a singular point,

FIG. 10 shows a first case of calculating the half tangent in a characteristic point,

FIG. 11 shows a second case of calculating the half tangent, FIG. 12 shows a third case of calculating the half tangent, FIG. 13 shows a simplified timing diagram, and

FIG. 14 shows a diagram of a device for eliminating the boundary points.

FIGURE 1 - According to Fig. 1 xd.rd the document to be analyzed on a Film presented at A to a television camera B, which is equipped with circuits for horizontal and vertical scanning.

The operation of the camera is clock-controlled by a time base C for main clocks, which is synchronized with a clock generator D. is. The time base C contains in particular two counters CL, Cp, whose Information is used to define the coordinates of a point, as will be explained below.

The video signal sent by the camera becomes a logic signal "0" or "1" behind a threshold circuit E, which hereinafter referred to as a.

The signals a combined in groups of three, which correspond to a line or line element (x abscissa), become a Circle F is fed to the majority decision in χ. This process, which has the consequence that the horizontal analysis accuracy divided by 2 has the advantage of eliminating isolated disturbances which would disturb the analysis. A Another process of majority decision-making in the vertical one Direction y is carried out in the organ G, which is also to it results in the accuracy being divided by 2 in the y direction.

The logic signals are then recorded in a processing memory H, which consists of eiiB? Composition in the form of a matrix arranged register.,

They are transferred to a cyclical auxiliary register J by a transfer circuit OL, based on the action of a processing monitor M. The order of the singular points which are found on a line segment is temporarily written into a memory Ή via a second transmission circuit Tp, where OL and J form a sub-arrangement V.

The eventual identification of singular points as characteristic Points takes place under the control of an organ P called the condition monitor, in cooperation with Organ Q, which is used to determine sequences of the same value in different registers of the processing memory 4, as well as the organ W, which contains simple wired logical conditions and logical decision functions.

When a point is recognized as a characteristic point, its coordinates are transferred to a buffer memory X, namely via a transfer circuit T, based on an organ S given command.

U is a circle to identify the boundary points which prevent It is possible that a point judged as a characteristic point which is actually a part is transmitted of a stain.

The coordinates of a characteristic point as well as the tangent at this point are written on a tape, for example by means of a punch Z.

FIGUB 2 - FIG. 2 shows the manner in which the logical video signals are taken from the scan lines of the document to be analyzed, via which the scanning line of the Xejnera runs.

00Ö83S / 1CU8

The signals are taken from a segment of length k on a line or line such as O ^ traversed in a horizontal curve χ. The same extraction takes place in a certain number of consecutive lines / 6, Ύ , etc., which cover a height h. The height h of an extraction area corresponds to 1L | vertical analysis steps. Due to the majority method, one analysis step in the vertical direction corresponds to two scanning lines.

In the direction χ are first on the width k of the removal zone smsi2; w defined individual points. Also due to In the majority method, one analysis step in the horizontal direction corresponds to two individual points. In an analyzed Line or line segment, there are thus signals taken from Hp.

In the course of a full scan of the document will be into memory H (see below) Mp removal signals in clearing χ brought to IL steps in direction y.

In the embodiment described below, N ^ equals 13 and Up equals 15 · This corresponds approximately to one almost square window that the removal area cuts out or takes out of the document.

In the course of the following full scan, the extraction area lowered by one vertical analysis step. d.E. by two lines.

This lowering movement takes place on the document from top to bottom in such a way that a vertical band B _n in the document is picked out in the course of N, = 183 successive scans.

This is followed by a "transition to removal in a subsequent volume B _n ,.

009836/1048

takes place roughly equal to half a volume.

The complete document is covered by N ^ = 35 bands.

The starting abscissa of a band is defined below by g, with 0 ^ g ^ 34- · The distance between a point and the starting edge of a tape is denoted by j, where 1 <■ j ^ 15 · The abscissa χ of a point is thus given by: χ = 7g + ü

The removal per previously described area is determined by the Processing memory H of FIG. 1 carried out, which 13 Has shift registers corresponding to the 13 vertical analysis steps, each of which has 15 positions that represent the 15th Correspond to individual signals per line segment.

The content remains during a period called "processing time" of processing memory -changed.

I ¹ IGTJR 3 - Fig. 3 shows an overview representation, the details of the sub-arrangements F, G-, H, J of FIG. 1 can be seen.

TMTERANOEDMJNG F -

The sub-arrangement F includes a shift register X with three Fächafo. or digits X ^, X ^, X *, the one with a majority arithmetic cycle MX works together.

The logical video signal that is generated by the threshold circuit E (Fig. 1) comes and occurs at a given point in time, is marked with. This signal reaches the place or the subject X, of the shift register X, has previously received the signal a. ^, which is now in the compartment Xp, and the signal a. p, that is now in the compartment X ^, located, vegwt.

Moving on in the register X takes place by means of a not shown feed or QJreiber line, namely

009836/1041

with a clock rate of 15 MHz.

The x majority circle MX works with the same clock sequence, who performs the following operation in a known manner:

bj = S ₁ *. H _1-1 + a _i _ ₁ -a _± _ ₂ + a _± _ ₂ . a ..

If two of the quantities "a" have the value 0 and only one has the value has, the output signal of the organ MX is 0. If two of the "a" has the value 1 and a single one has the value 0, the output signal is 1.

The purpose of such a majority circle is to remove the isolated disturbances that happen to be in a sequence of identical ones Valences can occur.

This result is explained in the graphs in FIG. 4-. 10 is the input signal of register X and 21, 22, 23, 30 and 4-0 are intermediate signals.

FIGUE 4- - Fig. 4- shows the shape of the at points 10, 21, 22, 23, 30 and 40 of Fig. 3 obtained signals. The signals are provided with the same reference numerals.

The signal at 10 coming from the threshold circuit E (FIG. 1) has, for example, two disturbances ξ and ξ "'which appear through an isolated valence in the middle of sequences of opposite valences MHz is taken, leads to the fact that in the subjects or places X ₅ , X ₂ , X ^ of the register X, the signals 21, 22, 23 arise.

At the output of the majority circuit MX, a signal occurs at 30, from which the disturbance values are eliminated.

009836/1046

This signal is at 40 with half the clock sequence, namely with 7} 5 MHz, which is also logical, because the Majority procedure, half of the accuracy is lost. This represents the price for eliminating the isolated interference.

The use of the clock sequence of 7 ₅ 5 MHz leads to technologically favorable arrangements which are much more economical than the case of preserving the original clock rate of 15 MHz.

The one present at 4-0 and taken with a clock rate of 7> 5 MHz Signal is the one above with b. designated signal.

After Pig. 3 the organs of the sub-assemblies G and H Register with 15 digits, corresponding to the division that appears at the bottom with 1, 2, 3, 4- .... 13, 14, 15 are designated. This designation is used to identify the order of the positions in all registers.

TMTERANORDMMG G -

The sub-arrangement G consists of three shift registers R ,, Rp, R ^, where the first two have 15 positions or subjects and the last one has a single digit. The positions or

1 15 compartments of R _x are with R, _Λτ . ...., R., ^, Etc. That

ο 3p1p 5

the same applies to the stelxes or subjects of R ^. The shift register R ^ has only a single place R _x,.

The signals defined above b. First all of them pass through register R ₅ , then all of them _{through register Rg 5} and finally the only place in register R ^. Through R ^ all information b., Which form an area extraction, run one after the other. In Rg the signals b ._ ^ are stored, which form the previous vertical analysis section, and in B, are

ORiQlNAL INSPECTED

000136/1041

those signals of the vertical analysis step that precede it are stored. Those signals that are generated first have the lowest or lowest indices, and this is the reason why the information is initially included in a. E ^ designated register, then enters Eo and finally arrives in Hy.

With regard to the signals b, the Ereis MY effects. the laugher

15 15 15 H.

or place E -i , E <> E ^ the same majority decision operation as before, with the same result. The consequence of this is that the number of analysis steps in the y direction is divided by two.

By removing one of two points in direction χ, then removing one of two lines in direction j , an accuracy is obtained which is equivalent in direction y and in direction χ. These measures are therefore logical.

The following signal is emitted from sub-arrangement G:

ed _ _a ü qÜ ι λ «<a« J j. / aW qW

where the indices 1, 2, 3 refer to the register with the same Refer to index.

SUB-ARRANGEMENTG H - ·

The sub-arrangement H or the memory H contains 13 labeled I ^ Eegister, where u are the from 1 $ to 1 from the bottom after Serial numbers running at the top and ν one from 15 to 1 from the left position number running to the right.

The ilgur was simplified by adding a. Part of the Border 8 belonging parts has been omitted.

009836/1041

This reversal of numbering is for the same reason as further up.

The corresponding signals are denoted ^{by e v.}

The signals emerging from the sub-arrangement G reach the lach 15 of the register L _x , ^, all pass through the register

15 ^ 1 L _x ,, from the point L _x , ^ to the point L _x ,. ,, then the register 1 ^ 2 beginning with the subject L ^^, etc. up to register L _x,.

If t denotes the duration of a period of frequency 7.5 (t = 133 ns), 3 ^ -0 t elapse between two Running through the analysis point on the same abscissa on two consecutive lines. Since a vertical analysis step comprises two lines, 64-0 t elapse before a new line segment is brought into memory. Since saving of a segment of 15 signals takes 15 t, remains a time of 680t - 15t, namely 665 t as available Analysis time.

SUBAITORDMJNG V -

The sub-arrangement V contains a transfer _{circuit T x} , and a shift register J of the type of a cyclic register or ring register with eight places or "compartments, which are shown in the form of rectangles. The compartments are with indices 8, 7» 6 in vertical Direction and 3 »2, 1 denotes in the horizontal direction.

Since the memory H is completely filled, the transmission circuit T _x , which can be of any type, on command of the time base C (Fig. 1) transfers the signals el, eS, el into the compartments Jo, Jo ₅ Jo ₅ aas signal e2 into compartment j2, the

XiOOo _x I (" ³ J 2. Λ '

Signal e _Q in the compartment J _n and the signals β ^, β ^, β ^ in the

. * ρ 1 '
Subjects Jg, J _x - and J _x -.

ο
The signal e ^ is of course not transmitted because it

Register J is a ring register and not one Die arrangement acts.

0Q9836 / 1CUS

2 The task of register J is to recognize whether the point e ^ is a singular point or not, i.e. a point that can be considered the "end" of a fingerprint line. This Detection takes place in a manner that is illustrated with reference to FIGS. 5 and 6 will be explained in more detail.

2 FIGURE 5 - Topology considerations show that the point e “as "End point" (singular point) can be considered if at the 8 points immediately surrounding it η are present that

2
e _n have the opposite value, with the condition:

Zj. ^ N ^ S 7

This is shown with reference to FIG. 5, which is represented by its four Configurations (a), (b), (c), (d), which correspond to the traps η = 4-, n = 5? n = 6, η = 7? correspond to the validity of the above condition shows.

The process of finding singular points, as described above has obviously an axis of symmetry of the 8th order. For this reason, the information contained in J Rotated 8 times around itself, as indicated by the arrows in FIG. 3, in order to check whether in one of the 8 positions the information contained in J satisfies a defined logical condition which practically expresses condition (1).

FIGURE 6-6 is used to explain the arrangement of the organs that work together in J processing, namely J, K, M, U.

In the course of processing, the information contained in the processing memory H rotates register by register itself. This comes from being affixed under each register

2 dashed lines for expression. In the compartment Lr ₇ , those at the start of processing run in at 13 consecutive times

2 14-information contained in _{subjects L 0} to L _n. the

009836/1048

1 15
Bins Lr ₇ and L ₇ are excluded because the environmental values of these points are not contained in the memory. Each of these analysis times corresponds to a value of j lying between 2 and 14.

For each of the 13 instantaneous _{states of the register L 7} , 8 readings of the information in the register J are carried out. This process takes 10 t, namely

1 t for transferring the information to J (see above) 8 t for rotating the information in J and 1 t for recording j (if applicable, if a regular point was determined).

The organ J has already been described with reference to FIG. ORGAN K -

The organ K is a logical circle, which at the entrance the valence,

or value L ₇ and the values of the 8 subjects from J and forms the following function:

2 2 ^^ 32? 2 ^ ^ ^ 2

λΛ T ¹ - T Τ- 'T-? Ts T _l TT T-2 T-? T- ³ T / OOfOO / Of (OG

If this function equals 1, this means that there is a sequence of η (4 · ^ - η ^ 7) consecutive valences with opposite polarity _{to L 9.} If this function equals 1 for one of the 8 configurations, the point L ^ is a singular point.

UHDERANOEDNUIiG M -

The sub-arrangement M, which is a processing monitor in J , contains three counters O ₅ , C ^, C ₅ . The counters G ^ and O ₂ receive the pulses to be counted on the time base 0 (FIG. 1).

The counter G, is a 10 counter which, due to its different

009836/1041

1944S43

successive states controls the transition to <T (1 t), the rotation in J (8t) and, if necessary, if a singular point has been determined in J, the transfer the coordinate j into memory (see below).

The counter G ₁ is a counter which identifies the visual value g of the point treated in the course of the successive rotations of the information in the register ί _π .

The counter C, - delivers a number of pulses (8 - η), where η is the number of singular points found in J in the course of processing.

OEGAU N-

The organ N is a memory, its access through a transmission circuit Tp is controlled.

For the conditions C ₅ , »10, the transmission circuit To carries out the transmission of the information j (counter G ^) into the memory Ή , which is a provisional memory. The circle T _{0 also} transmits the valence

2
speed ν of the affected point e "in I.

The memory IT contains five shift registers R with 8 each Places or Mucken. The information is shifted from one place to another one after the other.

The sub-register is used to record the value ν of a singular point. The four other registers beginning with 1, 2, and 8 are used to record the value of j of this singular point.

The coordinate g is supplied by a tape counter 0, which is in the 0 arrangement. The coordinate y is supplied by a line counter O ₀ , which belongs to arrangement 0 (SIg.1)

QG9836 / 1Q4S

Mr a number η of identified singular points (0 ^ n ^ 8), the counter G ₁ - 8 - η applies feed pulses to the shift register, which form the memory Έ ". The number / of singular points will always be less than 8 .

During the complementary pulses of the number 8 ~ n, the value O-is recorded in memory Έ. However, the value O cannot be a value of 3, which falls between 2 and 14-. Thus, the determination of a 0 at the output of this memory indicates that all singular points have been processed.

At the end of 13 cycles of 10 t, all points of interest of Lh are tested. The monitor then gives two additional feed commands in such a way that the information is returned to its original state. The information actually switches 13 steps forward while executing a full Rotation 15 steps are required.

I ¹ IGUR 7 - The remaining problem to be addressed by the device shown in Figure 7 is triple;

1. "Trace" the trajectory of the fingerprint line in the others Registers on both sides of

2. Once the configuration of the path has been determined, it must be compared with predetermined conditions in such a way that a decision can be made as to whether the singular point that has been determined and temporarily brought into memory Έ must remain stored as a characteristic point;

3 · Calculate the half tangent using the most suitable method at the position of the web.

These operations are performed using the following sub-arrangements;

009836/1045

Condition monitor (reference character P in Fig. 1), Sequence detector (reference Q in Fig. 1). These devices are shown in FIG.

Fig. 7 does not serve to show the interrelationships that appear in it To show organs. Such an endeavor would greatly expand the present description lead, but this does not appear to be necessary, since the teachings given are sufficient for a technician to set up and to understand the operation of the device according to the invention.

CONDITION MONITOR P

This subassembly "has the following elements:

A) counter C, -; B) counter G ₁ - ,; 0) Analysis switch with 13 directions.

A) Counter C ^. This is a conventional counter with a capacity of 21. It makes it possible to generate a certain number of faults that occur every 21 t. He is equipped with control devices P. and decoding means Pp.

The control means P ^, enable the triggering of the counter below the effect of a signal automatically generated by the processing circuitry in J at the end of processing. they allow it also stops the counter if either there is no longer any singular point to be processed (j = 0) or there is insufficient time (before 680 t) to process the following points (end signal of the available time).

The signal 0 = 0 is determined at the output of the memory N.

The "end of time" signal is given by the central Clock generator C supplied.

009836/1048

Me decoding means Pp perform the following operations;

- Decoding of the state 19 of the counter by copying the state 18 again, the transmission of the signal "State 18" forming the decoding of the state 19 of the counter. This state 19 is at the beginning of the recording commands (organ S, I ¹ Ig. 1);

- Decoding of states 16 to 20; this signal is used to release a restraint for further spread admit;

Generation of the command that enables the information to rotate in the processing memory H.

A sequence of 21 t runs in the following way:

From t = 1 to t = 15, the information rotates in L, that then works like a ring register. In the course of this rotation

away

the sizes s and s are recorded in their respective memories, on the basis of recording commands that are supplied by the organ Q.

From t a 16 to t = 18. During these three clock pulses happens nothing, and it is waited that the circles, which the simple logical conditions and the complex realize logical conditions, have reached their synchronization status. This waiting or holding is due to the complexity of the logical operations to be carried out, the require a response time of a certain length.

At t »19 the logical results are evaluated. Kick If state 19 is on, the result of the complex logical conditions is checked, and the feed and Recording commands (organ S, Fig. 1) be the result.

0098 3 6/1046

a) D ^ = 1. It then becomes a feed command without recording given, i.e. that the processed point is not recorded and a transition is made to the following point, namely to

D ₂ = 1 or D, = 1 or D ^ = 1.

In addition to the has

b) IL = 0. Feed / the command kai the recording of the quantities characterizing the point just processed.

c) D ₁ = 0, D ₂ = 0, D ₃ = 0, D ₄ = 0.

The point is analyzed by examining the contents of the following register.

At this point in time, the quantities s, s that have just been determined arrive in L in the memory s, s _ _, because they are the ones now serve as a reference for determining the valid sequence in the following registers.

To check the contents of the following register, the same state 19 causes the analysis switch to proceed by one step (see below).

During the interval t = 20, t = 0, the information becomes the Given time, the analysis switch to the subsequent detection circuits to spread, where it is then used.

In fact, not all 21 tonne cycles are strictly identical.

The first three cycles (which _{correspond to the analysis of L 1} - ,, Lg, Lg with q = 0, q = 1 (£ = + 1)) of course also last 21 t, but they have a special peculiarity.

.For q. = 0, the content of L ₁ - is checked, and there is already one

009836/1045

When the end of the sequence S _{7 to be} retained is known, a special circuit (sequence detection circuit in L ₇ ) is used to determine the other end S ₇ .

After Lr ₇ , the content of Lg is checked, if a rejection order of the point has not been given. No decision can be made during this cycle of 21 t.

You must wait until the end of the following cycle, during which the content of Lg is checked to see to which side the tangent is directed and whether it is also a breakpoint.

After these three cycles of a special kind there are five identical cycles with 2 ⁴ ^ qf < 6.

It can thus be seen that in the most favorable case eight cycles of 21 t are required to make a singular point valid Recognize point or reject it.

Since the "condition" monitor starts at time t = 152, the time to carry out 25 cycles of 21 t (up to t = 680) is available), which in the worst case scenario it is possible to have 3 points (3x8 = 24-) in the same line to process. Experience shows that this is sufficient.

B) Counter O ₇ - This counter C ₇ enables the sequential continuation of the successive analysis of the various registers L to be monitored. It shows the numerical value of the parameter q.

It has been mentioned above that the various cycles of 21 t during which the content of L is analyzed are not all identical. For certain values of q and thus of ρ (since ρ = 7 + £ q) it is necessary to have the

009836 / 1OAS

1944S43

To specify the working method of certain groups, i.e. the working method to adapt certain circles to the conditions that exist at the point in time under consideration. It just does it by means of a decoder which supplies seven suitable signals according to the individual status of the counter.

In order to avoid the occurrence of disturbances at the output of the decoder, the counter Gr _{7 was designed} in the mirrored binary code.

The different states of this counter, which are numbered 1 to 8 below, correspond to the following operations:

1 q = 0 it is analyzed L-, = L "q

2 q = +1 it is analyzed Lg = - ^ ₊ I

3 q = -1 it is analyzed Lg = ^ n-Λ

4- q = 2 it is analyzed Lp c

5 q = 3 it is analyzed

6 q = 4 it is analyzed l> r, ^ c

7 q = 5 it is analyzed Lr ₇ , - ^

8 q = 6 it is analyzed

The counter 0 _π thus alone controls the analysis of the first three registers (Ln, Lg, ^ g) * Finally, it is necessary to know the value of £ (+ 1) in order to determine which of the two registers that are equally distant from Coder will analyze.

The counter operates in the following sequential manner

- At the beginning of the conditions it is reset to zero.

- Every time a cycle of 21 t is carried out, it goes from state η to state η +1 via «This port scream th is caused by the state 19 of the counter G ^.

00 9 8 3 6/10 4 p

- 21 - 1944843

As soon as a decision condition has been checked (in the course of a state 19)> the counter C ₁ - is reset to 0 in such a way that the _{next singular point possibly contained in Lr 7 is} recorded or tackled.

C) Analysis switch P ^ - This organ is an address selector with 13 directions. Each of the 13 entrances is connected to the

Output of a register L (flip-flop L) connected. The on

PP *

^{Information e ü} present at one of these inputs is then selected by the selector and then arrives at the output, where it is recorded.

The selected input is indicated by the value of q and £ certainly.

There are three decoding combinations:

111

- Lg, Lr ₇ , Lg depend only on q;

I 1

- Ji, to Lr depend on q and on S = -1;

II e

to L depend on q and c = +1.

1
to L.-z depend on q and from

iOLGE DETECTORS Q -

There are two sequence detectors, namely a sequence detector in Lr, CLq and a sequence detector in L (/ 7)> Q? 0 *

Sequence detector in Lr ₇ CL ₀ - the task of this Unteranadnung is to determine the order of the point Br ₇ , which forms the other end of the sequence Y originating from a ^ in Ίδ ^.

Since this circle specializes in the content of L ₇ , it does not go over the analysis switch. It checks the content of at the exit of

00933671048

This sub-arrangement, which works essentially sequentially, can be divided in the following ways:

Order comparator Q ^ - valence comparator CV Transition detector (v_y) CL, - discriminator for the decision CL ^ - direction detector CL c.

Order _{comparator CL 1} ^ - This organ compares the content

of the counter Cg with the value s ^a . If these two values are equal, it generates a signal that indicates that at this point in time the information passing through _{the position or the! Compartment L 7}

mation of order S _{7 is recorded} by the sequence detector.

Value comparator CLp- Dieaa? Circle compares to everyone Point in time the valence checked by the subsequent detector or Valence ν with the valence or valence of the singular en Point in the course of processing.

This circle responds every time the valences to match. He makes it possible by means of a single circle the case of the black points (v = O) and the white points (v = 1) to be processed.

Transition detector CL, - This circuit delivers a signal each time in the course of checking the content of Ij ₇ when two successive valences or valences eä are different. · ■

In fact, it is the sequence boundaries that are the points of interest in the analysis that are defined by transitions in Appearance. Let ν be the value of a point in the course of processing; a transition ν ν, which is called the rising edge M, shows the beginning of a sequence or sequence from ν on; a transition ν ν, called the falling edge D. is, indicates the end of an episode «

009836/1048

For j = 1 and g = 15? i.e. the abscissas of the ends of a Segments, a simple additional logic indicates the presence of a rising edge or falling edge if the Valence of the corresponding points ν is.

Discriminator Q ₁ ^ - This is the decision-making body of the sub-assembly. It has two flip-flops which are controlled by a logic which combines the signals emitted by the comparator of the order Q -. ,, and the transition detector Q. At the output of the discriminator Q. ^ there is a circle which sends out the recording command from S ₇ .

Calibration detector Q ^ t- - This circuit contains a flip-flop which indicates the relative value of Sn and S _{7 by means of a signal S.}

I sS ^ s ^ got S = O. For s ^> s ^ we get S = 1.

This flip-flop is reset to zero when the following singular point is attacked, i.e. by the feed command.

_{Following detector} in L, Q 0n - This sub-arrangement enables

• P from a

the control of the recording 'of s and s, if s

κ PP P ~ c

and s ". are known.

ρ-ε

Like the detector D _{7, it} can also generate several commands in each family (a or b), but it is the last of each family that is the good or correct one.

He has organs similar to those of the detector D _7, namely Trim comparators Qp ^, ΟρΛ \> ~ ^e i ^nen Valence comparator Qp ₂ - an Uber-crossing detector Qp - a discriminator

009838/1048

1944843

, ■ Order comparator a - This circle compares at each point in time the content of the counter C ^, with the quantity s ^a , which is recorded in its corresponding memory; as before, the coincidence triggers the transmission of a signal.

Qo-ih 5 Comparator of order b - This is a Circle as before, which is intended for the other end of the last known sequence, namely the size s.

Significance comparator Q ₂₂ - This circle, which is identical to that of the detector D ", compares the significance that occurs at the output of the analysis switch with the significance of the examined singular point (stored in memory J).

Transition detector Q ₂ , - This is identical to the transition detector Q ^, both in terms of structure and mode of operation.

Discriminator Q ₂ ^ - This has two flip-flops like the discriminator Q ^.

Soft Q ₂ , - - In the Fo Ige detector of Lr _{7 there} was only a need for a single recording command in the memory s_, since the point in the course of processing is by definition sS and the extreme point of the sequence in Lr _{7 is} point S ₁ -, is.

In another register L, if you click on a first End of one episode and then meets a second, the record

away
tion in the memories s or s in such a way that the segment ss the same direction as the segment s "S _{17 is} given. This selection is made by the recording switch based on the above-mentioned logical function S.

009836/1046

Device for displaying the presence of a sequence A sequence is always present in register L ^ (in the borderline case with a single digit). A flip-flop shows in the course of each cycle of the counter C ₂ . whether there is a satisfactory result. This is condition "N" (which is one of the simple conditions, the full list of which will be given below). For N = 1 there is a sequence in L; for N = O there is no sequence and the trajectory of the fingerprint line is broken.

QZ ₀ - memory. The sequence detectors are equipped with memories, the task of which is to temporarily store the abscissa of the ends of the sequences.

For each register L must be brought into memory

from P

s, s as well as those relating to the previous register

PP from

dragging information s _,, s, to the orbit of a Register to the following register to trace.

a b Furthermore, special memories are required to store Sg, Sg to save while testing L ^.

A total of six memories is thus obtained, which support the operation of the sequence detectors Q ^ (s ^), Q, p ( ^a r) Q ₅₅ (Sp), Q ₅₄ (Sp), Q ₅₅ (S ₈ ¹ ) , Q ₅₆ (Sg).

- Determination of £. This circle determines the polarity of £ (+ 1) with the help of two memories which each determine the presence of a sequence in Lg or the presence of a sequence in L ₈ , which are assigned to a decoder. Among the four decoded states, one corresponds to £ * +1 and one corresponds to £ ■ -1.

The processing procedure is as follows:

009838/1048

The course of a fingerprint line occurs in the die 8%. in appearance through the juxtaposition of a certain number of sequences of a certain valence or value, each being contained in a register L. One of the-

P from

A similar sequence contained in the register L is denoted by s - s, where ρ is the index of the register and a and b denotes the abscissas of the ends of the sequence.

In the register L is the point of origin of the sequence s ^; this is the point recognized as a singular point in the previous operation. The other end of this episode is “.

It is searched first in Lo and then in L, - whether a sequence exists which at least one position or one subject of

from the same valence or valence as Sr ₇ - has s ", so that

If a sequence is found on each side of L “that corresponds to the corresponds to the above condition, the point sS is obvious not a characteristic point as it is not an "end" point; it is therefore rejected or discarded.

The register following L ₁ -, in which a sequence is found, determines the area of the processing zone in which the analysis must be continued. If this is L _g , the area («1/2 zone) is denoted by ε = +1. When this is Lg, the range is denoted by t--1. This designation enables the register of the matrix to be defined generally in the following form:

L a L _n + _
with C = + 1, 2 ^ q <, 6. ■

009836/1045

The registers are then queried in the following series episode :

Determination of

_£ ( _oaer

^L 7 + 2 £ ¹ V ₊ SC

If in the course of such a query the trajectory of the fingerprint line reaches one of the edges of the die and if this path meets certain conditions, the following are specified, the singular point Sn becomes more characteristic Point is detected and the encoder approximates the tangent to the line at that point. If the signs or the course are considered abnormal; the point is discarded.

The determination of the validity of a point is thus the result the comparison of numerical elements, which represent the path, with certain complex logical conditions, which in turn are logical functions of simple conditions.

The following are the simple conditions:

009838/1 OAS

1944243

These conditions are indicated in capital letters, in the same way as certain subassemblies of the device, but for this reason there is no confusion to fear.

One of the ends of the marked or determined in line L The result is the left edge of the processing memory.

C) s * = 15

Jr

D) ej -15

One of the ends of the sequence determined in line L reaches the right edge of the processing memory.

E) s- -β *

contains
The sequence of the line L “o only has one element.

These inequalities characterize a very small increase the absolute value with respect to the abscissa along the fingerprint line; the axis of the fingerprint line closes a very slight angle with the vertical edge of the processing area a.

s £ - B *

s £ - s ^a

009836/1045

These inequalities express that the increase of the abscissa value along the fingerprint line is very large is; the axis of the fingerprint line makes a very small angle with the horizontal edge of the processing area a.

The conditions F, G, H, J only have a strict meaning for the marginal register L, namely ρ »1 or ρ = 13, i.e. q = 6.

sr

K) (s * -s *). (s £ e *) <0

The characteristic point has an abscissa extending into the interval which is formed by the extreme abscissa values of the sequence present in the line L.

FIGURE 8 - This condition, in conjunction with FIG. 8, expresses that the angle of the vector a ^ -b ^ with the vector b a is acute (Angle CJ).

If this condition is not met, there is an obtuse angle Cd (or a right angle for the Equality with zero).

M) M - 1 for q = 6

After six consecutive lines, the analysis has the upper margin, or /%1)ere end (L ^) or the lower end (I ^ *) of processing memory reached.

N) The condition N-O means that in the register L there is no satisfactory result; the fingerprint line is therefore interrupted.

009838/1045

- JO -

0) (si? - ^ _{+ e} (

This condition is similar to condition L, but the point to spit

plays.

an plays the role that the point a _fi in the condition L

P) The condition P = 1 means that at the same time in L, - and Lg is a satisfactory pole.

Q) The condition Q = 1 has the meaning ρ = 7 · R) The condition R = 1 has the meaning ρ = 8.

The elementary simple conditions outlined above are integrated in the validity of divorces, to which reference is made below:

Decision D ^: This decision eliminates certain points •for the following reasons:

- irregularities in the path of a line away from a stopping point;

- Stopping point too close at the left or right end of the processing die, if in addition the half tangent is directed to this same end;

- Elimination of one of the two singular points that are on the same line. The best is the one who is on the side to which the semi-tangent is directed when the slope is 1 in absolute value 7, and on the opposite side Trap is the best point on the other side. -

The decision Ί) _Λ is to be written as follows:

009836/1046

F ₁ .H ₁ .Z + AF + BH + CF + DH + 1GL + 1J.IM0 + N + P + M.Ü.GLE + O. "GFHLME + (B + D) jW

ty

The decision D ₁ is a condition for rejecting or accepting a singular point as a characteristic point.

The decisions Dp to D ^ relate to the selection of the Quantities that are included in the calculation of the semi-tangent at a point recognized as a characteristic point.

In the following, the cases are given to which the various expressions of condition D ₁ correspond, in order to give a precise idea of the operation of the device, whereby no further explanation is given.

1 - -
D _-1 = F ₁ .H ₁ .K an is not characteristic: the line

has a dislocation, but a, -, is no end point.

D = AF B.TJ is too close to the edge of the area to

enable an accurate calculation; it will be in the following area again be taken up.

ΊΚ - bra. on is too close to the edge. D ₁ = CF a ™ is too close to the edge. D ₁ = DH ar, is too close to the edge.

D ^ »E.G.L The singular point a ^ is for the calculation the tangent is not the best point and is therefore rejected.

= E.G.L.M The singular point is not the best for the calculation of the tangent and is therefore rejected.

009836 / 104S

³² "1944843

D ₁ = N The history of the fingerprint touched

no edge of the die, it is

to a glitch.

D ₁ = P. This condition indicates that there is a satisfactory sequence in Lg and Lg. a _n is not characteristic. This case is shown in FIG.

"IQ _

D ₁ = EGLMO The slope of the tangent is too small.

D ₁ = EFGHLMO irregularity in fingerprint

line.

D ₁ = (B + D) .7F.Q Rejection condition which is intended to

eliminate the singular points that might be computed even though they are not at a breakpoint. This error can arise because the content of the memory is limited.

The decisions D ₂ , D- ,, D ₂ , which relate to the calculation of the half-tangent for a point recognized as a characteristic point, are now briefly discussed.

Condition D ₂ is as follows:

D ₂ = QRM (B + D). J + EGLMO + EFGHM

In all cases covered by D ₂ , the half-tangent is calculated as follows:

FIGURES 10-10 show a case of applying decision D ₉ to the computation of the half tangent. That’s what it’s about

1
dealing with the case of Dp.

009836/1 046

Eat divorce D,: this decision reads: (E. J ¹ .GHLM) .0 + E (GHM)

In. the tangent is calculated for the above spheres using:

PIGTIR 11 -! Ig. 11 shows a case of applying the decision D ₇ T to the calculation of the half tangent.

Decision D ^: this decision reads;

(P + H) .M
In the above cases the tangent is calculated using;

PIGUR 12 - Pig. 12 represents a use case of the decision Dn for the calculation of the half tangent.

The pingerprint encoder finally provides the following Information which is based on one of a recording and Feed command circle S given to a transmission circle T. Command to be stored in a buffer Y before they are recorded by a punch Z:

J ^ Si Dj which determine the position of the point; Ύ and O ^, which make it possible to calculate the tangent at their point.

PIGUE 13 - Pig. 13 shows, in simplified form, a general "schedule" of the various phases of operation:

009836/1045

1944843

It consists of two representations, namely the representation a) and the illustration Td).

Representation a) relates to the processing memory. In a complete cycle of 680 t, the information enters the memory for 15 t, then takes place between 15 t and 152 t, the processing in the register J "takes place. From 152 t to 680 t, processing takes place in the subsequent detectors.

Representation b) relates to the progression of the information in the register R ^; it takes place twice during a cycle of 680 t, namely between 0 and 15 t and between 340 and 355 t.

FIGURE 14-14 is an operational diagram of the circuit for Elimination of the boundary points.

The task of the circle to remove the boundary points is to to systematically remove all the points which are readily regarded as singular points by the encoder, because a fingerprint line meets an area of uniform significance, namely the edge of the one to be analyzed Clichés or a spot in the interior of the cliché, for example from a scar on the finger from which the Imprint comes from, comes, etc.

It is clear that the encoder considers each point of contact as a singular point between a fingerprint line and a uniform area of opposite valence or valence will accept. It was therefore decided to exclude from the processing all points that are on the scope of such an area or spot and are referred to as boundary points.

QQS336 / 104S

The principle is to detect a spot or area of minimal size in the processing die is too big to be a line element. The dimensions and the shape of this reference spot or reference area are included chosen in such a way that there is a high probability that an area of uniform coloring will be considered suspect "Can, using a 6-step by 6-step square shape. A round or polygonal shape would be has been more justified, but the square makes the circuits very simple.

The circle consists of two identical sub-arrangements, which each from two sides of L-, check whether there is such a square of 6 by 6 compartments. Everyone knows essentially a counter Og, Cq, whose outputs go through an OR circuit 50 are merged, from which a signal 0 exits (limit point suppression).

A square contained in the registers L _x , to L ^ - (for example) is determined in the following way:

In the course of the entry of new line or line information a circle checks in parallel the six valences forming a column, which for 15 t at the exit of the six tilting

111111
steps L ^, L ₀ , L ₂ , L,., L ₁ -, "L _r walk past.

I cL y H- ρ ο

The corresponding counter works in the course of the 15 times t as follows:

At the beginning it is zero.

If at a time t a column of six are identical Valence occurs, the counter goes to position 1.

If no column is found at t, the counter becomes reset to zero because it has not reached state 6.

009836/1045

If a column is found at t whose valence is contrary to which the column is that at time t. established the counter is set to 1 (case of the strictly vertical fingerprint line).

If at a given point in time the sequence the counter up to

in fact

If state 6 comes, it remains blocked there / until the entrance of a following line; this state 6 indicates the presence of a minimum stain on the side of Lr ₇ corresponding to the counter. When either of the two counters reaches its state 6, the point is considered a limit point.

- patent claims -

008836/1048

Claims (8)

Patent claims 1.! Device for coding fingerprints, in which a fingerprint cliché to be examined is analyzed by an industrial television camera with successive line-by-line horizontal scanning, which behind a threshold value circuit is a signal called a video-logic signal with the logic v / ert 0 or the logic value 1, which is processed with the means of electronic logic, whereby at the end of the analysis the numerical parameter values identifying the analyzed fingerprint are recorded by punching, characterized in that a processing memory is provided which consists of IL shift registers each with No positions or Fan consists and during a certain time, called processing time, _{receives and stores the valences or weights of H 2} points, which segments on each of IL form lines (or vertical analysis steps, which can have more than one line or line ) that the in that Information contained in the processing memory forms a "window" on the document to be analyzed, that the window is lowered by one step after a processing time has elapsed in such a way that after N ₅ , lowering of one step, a vertical band picked out of the document is scanned, whereupon the scanning of a subsequent band takes place anew, which is obtained by lateral displacement by a width which is approximately equal to half a band, the document as a whole being covered by scanning of N ^ bands. 2. Device according to claim 1, characterized in that that switching devices are provided to each video-logical signal through all arranged in series Run registers as if the iL were arranged one behind the other Register would form a single shift register. 009836/1045 3. Apparatus according to claim 2, characterized e t that devices are provided in order to enter the valences in a cyclic register J with eight positions or subjects or to transfer valences of eight places or subjects, which the penultimate place at one end of the middle Register of the processing memory surround that means are provided to store the transferred information in the cyclic To rotate registers, and that logical facilities are in place to identify the penultimate, if necessary Place as a special point, namely a singular point, to enable accordingly. 4. Apparatus according to claim 3, characterized e t that logical means are provided to decide whether a singular point is effectively the end of a fingerprint line and represents a characteristic point- ' represents, and that in the event that this is the case, means are available for the coordinates of this point as well as the Record the slope of the tangent at this point. 5. Apparatus according to claim 4-, characterized marked eichn e t that the logical devices have connections, which is the rotation of the information contained in each register in circular permutation in the register guarantee. 6. Device according to one or more of the preceding claims, marked by a first majority decision circuit arranged behind the threshold value circuit in the horizontal direction, a second mathematical decision circle in the vertical direction, one Processing memory, a first transmission circuit .cyclic register in which the transferred information is stored under the effect of a processing monitor is processed, 009836/1045 1944843 in dependence on logical conditions that are written in a memory, a memory in which the rank of the singular point or points found on a line segment when passing through a second Transmission circle, a condition monitor, who works with an organ Q that is responsible for determining the sequences of the same valence or valence in the successive registers of the processing memory serves, and an organ that contains wired simple logical conditions and logical decision functions, as well as a buffer storage in which the characteristic Elements (coordinates and gradient of the semi-tangent) of a characteristic point can be introduced on a command, that of a recording and feeding device via a third transmission circle is given, as well as a circle for limit point determination, which makes it possible in the processing memory to find at least two column groups of six compartments or locations which are the same Possess valence or valence, and finally a hole punch. 7. Apparatus according to claim 6, characterized in that marked e i c "h - n e t that the circle to determine the boundary points essentially has two counters, which are used to count the columns of six places or subjects of the same value in the Processing memory on both sides of the middle register are used. 8. Device according to one or more of the preceding claims , gekennz eichnet that a timer is provided which is based on the time base of the television camera is synchronized and to clock for all processes serves. 009836/1045 Blank page