JPS6013513B2 - Automatic seal imprint verification method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an automatic seal imprint matching method for determining whether the imprints match or do not match.

(Background Art) FIG. 1 shows an automatic verification device for the imprint of a subordinate seal.

FIG. 1 shows a seal imprint pattern 2 to be verified which has been read by a checker section 1, which is moved and rotated by a position matching section 3.
The match comparison unit 4 checks the degree of match with the registered seal imprint pattern 5, the match judgment unit 6 makes a judgment, and if necessary feeds the results back to the position matching unit 3 to move in the direction of improving the match degree. After performing the rotation, the degree of coincidence is checked again by the collation/comparison section 4, and this process is repeated to determine the authenticity of the seal imprint to be tested based on the maximum value of the degree of coincidence. Therefore, in the case of this device, it is necessary to repeat a large number of ``position matching'' and ``verification comparisons'' before a determination result is obtained. By the way, "verification and comparison" generally scans the entire pattern and checks whether dots on the mesh that correspond to each other match each other or not.
Requires considerable processing time.

Therefore, performing "verification comparison" many times means that
This leads to the disadvantage that the time required for verification is very long.
As a conventional example for improving this drawback, for example, Samurai Sarasho 56-205111 (Tokukan Sho 58
-106659), the external features such as the external shape and external dimensions of the seal imprint pattern are extracted, and if the external features of the registered seal imprint pattern and the external characteristics of the matched seal imprint pattern are different, the There is a method of determining ``unmatched'' without the need to perform a ``verification comparison,'' which is very effective in reducing the time required for verification.

However, some seal impression patterns have the outer frame and characters in contact as shown in Figure 2A, while others have the outer frame and characters separated as shown in Figure 2B. If the external shape and external dimensions of The disadvantage was that there was little leeway in setting the match rate threshold for determining "non-match".

(Problems to be solved by the invention) An object of the present invention is to determine contact/separation between the outer frame of a seal imprint pattern and characters, and to determine whether one of the registered seal imprint pattern and the to-be-verified seal imprint pattern is in contact, in order to eliminate these drawbacks. , when the other is separated, it is determined that there is a mismatch without performing "position matching" or "verification comparison" of both seal imprint patterns, which will be described in detail below.

(Structure and operation of the invention) FIG. 3 shows a first embodiment of the present invention, in which the characters are in contact with the outer frame of the seal imprint pattern 2 to be verified, which is read by the reading unit 1. The contact/separation determining unit 7 determines whether the character is in contact with the outer frame of the registered seal imprint pattern 5 that has been registered in advance. The feature comparison unit 9
When the two judgment results are compared and the judgment results are different, that is, when one is "contact" and the other is "separation", the operations of the position matching section 3 and the matching comparison section 4 are stopped, and the matching judgment section 6, and if the contact/separation determination results for both seal imprint patterns are equal, this is a magic trick that determines the authenticity of the tested seal imprint using the same processing as the conventional example.

Although a configuration has been described in which one contact/separation determining section is provided for each of the two seal imprint patterns, a configuration in which one contact/separation determining section is shared by both the seal imprint patterns is also possible. FIG. 4 is a block diagram of the contact/separation determining units 7 and 8 in the first embodiment of the present invention, and the outer ring line tracing unit extracts the outer ring line by tracing the outline of the long outer shell of the seal imprint pattern outer frame. 10, a shape recognition unit 20 that recognizes the shape of the outer ring line, an inner ring line tracking unit 30 that traces the outline of the inner side of the outer frame of the stamp pattern to extract the inner ring line, and a shape recognition unit 40 that recognizes the shape of the inner ring line. and a determination unit 50 that determines "separation" when the outer ring wire shape and the inner ring wire shape are different and "contact↓equal".

Here, the outer ring line tracing section 10 may be a known 8-connection contour tracing.

That is, as shown in FIG. 5, the x-axis direction is the main scanning direction,
Scanning is performed with the Y-axis direction as the sub-scanning direction, and the first black V point (in the case of a binarized pattern, a point with a value of 1) S is found.
For example, 8-concatenation-boundary tracing algorithm [Transactions of the Institute of Electronics and Communication Engineers, Vol. 56-D, No. 11, pp. 667-6 (1973
)], the contour point sequence L is obtained. (named outer ring line) can be extracted. In addition, the inner ring line tracing unit 30 performs scanning in which the x scale direction is the main scanning direction and the Y axis direction is the sub scanning direction, as shown in FIG. Starting from the value M, first move from black point to white point on one main scanning line.
By finding a black swan point Si that is a black point at the boundary when this change occurs and is not a point on the outer ring line, and applying the above-mentioned 8-connection-boundary tracing algorithm using the black point Si as a starting point, the contour point sequence L, (named the inner ring line) can be extracted.

The outer ring wire L thus obtained.

The shapes of and inner ring line L; are recognized by the shape recognition unit 20 or Yotsukawa, respectively, and the shape recognition unit is
For example, Taru Gansho 56-205111 (Mochiseki 58-106
659), while linearly approximating the contour point sequence,
The conventional method of extracting line segment information and angle information from the intersection angles formed by adjacent approximate straight lines and classifying the outline shapes into circles, ellipses, quadrilaterals, and other shapes may be used. In this case, for example, in the case of a stamp pattern in which the outer frame and the characters are separated, as shown in FIG. 7A, the inner ring lines L and the outer ring lines L, respectively.

The outer ring line shape and the inner ring line shape are the same because they are similar shapes that are slightly smaller than . On the other hand, in the case of a seal impression pattern in which the outer frame and the characters are in contact,
As illustrated in FIG. C, since the inner ring line Li traces the inner characters, the inner ring line shape is generally not a circle, an ellipse, or a quadrilateral, but other shapes, which are different from the outer ring line shape.

Furthermore, even if the inner ring wire shape happens to be a circle, an ellipse, or a square, it is rare that the inner ring wire shape is exactly the same as the outer ring wire shape. The 414 stamp patterns obtained from the seals of 55 fleas were confirmed experimentally, and the outer ring line shape and inner ring line shape were the same for all 129 separated seal impression patterns, and all 28 contact seal impression patterns were confirmed experimentally.
Of the 9 types, 281 types had different outer ring line shapes and inner ring line shapes, and only 8 types had the same shape, and this case was the case shown in FIG. 7D.

8 patterns out of 41 turns is just under 2%, and can be considered a practical correct answer rate.

However, depending on the application, even a yield of less than 2% may not be acceptable, so in that case, the contact/separation determination section may be configured as shown in Figure 8, for example, to achieve a perfect ratio of yields. Can be done.

In other words, in the case of a separated seal impression pattern, the outer ring line shape and the inner ring line shape are not only equal, but also their center points almost coincide, whereas the outer ring line shape and the inner ring line shape are This method focuses on the fact that if the line shapes happen to be equal, the center point of the outer ring line and the center point of the inner ring line will be largely separated. In other words,
The shape comparing section 45 compares the outer ring line shape and the inner ring line shape, and if the shapes are different, it is determined that there is "contact", but if the shapes are the same, the center point detecting sections 60 and 70 detects the center points of the outer ring line and the inner ring line, compares the center points in a center point comparing section 75, and when the distance between the center points is larger than a predetermined relationship value, it is determined that there is "contact",
If it is within the predetermined threshold, it is determined to be "separated". Here, the center point detection units 60 and 70 are configured such that, for example, the average value of all the X coordinates of the contour point sequence is set as the X coordinate of the center point, and the average value of the Y coordinates of all points is set as the Y coordinate of the center point. Any known method may be used. In addition, in the above-mentioned contact/separation determination section, when the outer ring line shape and the inner ring line shape are equal, the separation of the center points of both inner and outer ring lines is used as an auxiliary feature for contact/separation judgment. However, it is also possible to use as an auxiliary characteristic whether the outer dimensions of both contour lines are substantially similar or significantly different. As explained above, in the first embodiment, "contact/separation information between the outer frame and characters", which is a type of internal feature of the seal imprint pattern, is extracted from each of the registered seal imprint pattern and the Iso verification seal imprint pattern, "Contact/separation information" for both seal imprint patterns
If the two seal impression patterns are different, the "position matching" or "
This method has the advantage that the matching time can be shortened because the "coincidence judgment" is made immediately as a mismatch without performing a "verification comparison".

Moreover, in the case of a pair of seal impression patterns in which the outer frame shape, outer frame dimensions, and inner characters are almost the same, the only difference is the contact/separation relationship between the outer frame and the characters. Even if it is difficult to determine the authenticity based only on the matching rate, the contact/separation information of both seal imprint patterns can be used, so the accuracy of "match determination" can be improved.

The first example is "contact/separation information" for both seal impression patterns.
We have explained a configuration in which if the two seal imprint patterns do not match, it is immediately determined as a "mismatch" without performing "position matching" or "verification comparison" of both seal imprint patterns. Rather than making a judgment based only on the matching rate, scores are allocated in accordance with the matching rate of matching, as well as the degree of matching of various extracted features such as external shape, external dimensions, and contact/separation information, and the overall score is calculated based on the matching rate. It goes without saying that "contact/separation information" can be used effectively even in the case of a configuration in which match/mismatch is determined based on scores.

Furthermore, in the first embodiment, the case where "contact/separation information" is extracted from both the registered seal imprint pattern and the matched seal imprint pattern has been described, but for example, when registering, the label information of the registered seal imprint pattern is It goes without saying that if the "contact/separation information" is encoded and registered, it is sufficient to extract the "contact/separation information" only from the stamp imprint pattern to be verified.

(Effects of the Invention) The present invention includes a contact/separation determining unit between the outer frame of a seal imprint pattern and characters, and detects "contact/separation information" of a registered seal imprint pattern and "contact/separation information" of a seal imprint pattern to be compared. Since the information is reflected in the "match determination" as to whether the two are the same or different, the overall verification time is short and the "match determination" is highly accurate and can be used in an automatic seal verification device. .

[Brief explanation of the drawing]

Figure 1 is a block diagram of the automatic verification device for subordinate seals;
Figure A is an example of a seal impression pattern where the outer frame and characters are in contact.
FIG. 2B is an example of a stamp pattern in which the outer frame and characters are separated, FIG. 3 is a block diagram of an embodiment of the present invention, and FIG. 4 is a contact/separation determination unit in an embodiment of the present invention. , FIG. 5 is an explanatory diagram of an outer ring line tracing section in an embodiment of the present invention, FIG. 6 is an explanatory diagram of an inner ring line tracing section in an embodiment of the present invention, and FIGS. 7A to 7 D is a diagram for explaining the relationship between the stamp pattern and the outer ring line and the inner ring line, and FIG. 8 is another example of the configuration of the contact/separation determining section in one embodiment of the present invention. 1...Advisor section, 2...Seal imprint pattern to be verified, 3...Position matching section, 4...Verification comparison section,
5...Registered seal imprint pattern, 6...Concordance judgment section, 7, 8...Contact/separation judgment section, 9...
... Feature comparison section, 10 ... Outer ring line tracking section,
20... Shape recognition section, 30... Inner ring line tracking section, 40... Shape recognition section, 45... Shape comparison section, 50... Judgment section , 60, 70...center point detection unit, 75...center point comparison unit, S. ....Outer ring line tracing starting point, L. ...Outer ring line, Si
...Inner ring line tracing start point, L, ...Inner ring line.
;(' Figure Uki L2 Figure 3 Figure 5 Figure Son L4 Figure Tuna et al Figure 7 Figure 8

Claims (1)

[Claims] 1. Reading the stamp impression to be verified as an electrical signal by a reading section,
The position of the seal imprint pattern to be verified read by the reading unit is aligned with the registered seal imprint pattern by the position matching unit, and the comparison and matching unit compares the two seal imprint patterns. In the automatic seal imprint matching method, the matching judgment unit determines whether the two seal imprint patterns match or do not match and the position matching unit instructs the position matching unit to readjust the position matching according to the matching result, which is the output thereof. a contact/separation determination unit that determines whether the seal imprint outer frame and the internal characters are in contact or separated from each other and outputs contact/separation information, and the contact/separation determination unit is , an outer ring line tracing means for extracting the outer ring line of the outer frame of the seal impression pattern, an inner ring line tracing means for extracting the inner ring line of the outer frame of the seal impression pattern, a shape recognition means for identifying and classifying the shape of the outer ring line and the shape of the inner ring line. , determining means, and determines that the seal imprint outer frame and the internal characters are in contact when the shapes of the outer ring line and the inner ring line are different, and determines that the seal imprint is in contact when the shape of the outer ring line and the shape of the inner ring line are equal. Automatic verification of seal impressions, characterized in that it is determined that the outer frame and the internal characters are separated, and the coincidence determination section also uses the determination result regarding the contact/separation as information for comparison determination of both seal impressions. Method.