JP2005292888A - Identification code issuing/recognizing system using fractal figure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To issue a commodity identification code suitable for reading by a digital camera or a camera-equipped cellphone, and to recognize it. <P>SOLUTION: Various fractal figures are made to be generated by a fractal figure generation means 10, and are registered in a registration means 50 respectively correspondingly to the specific commodity identification codes. At that time, a dimension calculation means 40 is made to calculate a fractal dimension of each the fractal figure, and the registered figure is selected by a selection means 30 such that a dimension value is not overlapped. Thus, the fractal figure registered in the registration means 50 is issued by a code issuing means 60 as the identification code C, and is attached to a commodity G. The identification code C input as image data by a code input means 70 such as the digital camera is sent to a code recognition means 80, the fractal dimension is calculated here, and the registration means 50 is referred to, so that it is recognized as a prescribed commodity identification code. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an identification code issuance / recognition system using fractal graphics, and more particularly to a system suitable for issuance and recognition of an identification code attached to a product.

  Currently, many products distributed in the market are each assigned a predetermined product identification code. Such merchandise identification codes are input to a POS management system or the like and used for merchandise management. Also, libraries and rental video stores attach identification codes to all books and videos, and use them for lending and return management.

Such an identification code itself is usually composed of a combination of European characters and numbers, but when attached to a product or the like, a form suitable for reading using an optical device such as a barcode is taken. . Recently, two-dimensional barcodes capable of increasing the amount of information compared to ordinary one-dimensional barcodes, and identification codes having various characteristics are used according to the properties of products to be attached. For example, Patent Document 1 below discloses a thread-like two-dimensional bar code suitable for attaching to a cloth product, and Patent Document 2 discloses a vertical bar suitable for attaching to a leaflet. The code is disclosed. Patent Document 3 discloses a barcode printed with a dye or the like that changes color over time so that the freshness of foodstuffs can be displayed.
JP 2000-008269 A JP 2003-150895 A JP 2003-203210 A

  As described above, an identification code such as a barcode is attached to many products currently on the market, and various forms of this identification code have been proposed. However, all of the currently proposed identification codes are premised on reading using a dedicated code recognition device, and are not suitable for reading using a general-purpose image capturing device.

  For example, in a supermarket, barcodes attached to individual products are read using a dedicated barcode reader device installed at a cash register. As long as a conventional general identification code such as a bar code is read using such a dedicated code recognition device, there is almost no trouble such as a reading error. However, the general identification code attached to the product is captured by the purchaser of the product with a digital camera or camera-equipped mobile phone and captured as image data on a personal computer. The identification code is recognized based on this image data. If processing is performed, various problems may occur. Specifically, if the shooting angle and the image resolution are inappropriate, correct recognition cannot be performed. Of course, even when a part of the barcode is out of the field of view, correct recognition cannot be performed.

  In the future, it is expected that the communication environment such as the mobile phone network and the Internet will be further enhanced, and at the same time, terminal devices at the personal level such as mobile phones and PDAs will be further spread. Therefore, there is a possibility that the usage form in which the purchaser himself / herself photographs the identification code attached to the product and transmits it as image data may gradually spread. However, conventional identification codes such as barcodes are inappropriate for such usage forms, and an identification code having a new form is required to cope with such usage forms. .

  Accordingly, an object of the present invention is to provide a system for issuing an identification code suitable for reading using a general-purpose image capturing device and recognizing the identification code.

(1) A first aspect of the present invention provides an identification code issuance / recognition system,
A fractal graphic generation means for generating a fractal graphic using a predetermined algorithm and a predetermined parameter;
Generation control means for generating a plurality of different fractal figures in the fractal figure generation means by changing at least one of the algorithm and the parameters;
Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
Among a plurality of different fractal figures generated by the fractal figure generation means, with respect to a figure having the same fractal dimension calculated by the dimension calculation means, only one of them is selected and a selection process is performed to discard the other. A selection means;
A registration means for registering a fractal figure that has not been discarded by the selection means in association with the fractal dimension;
A code issuing means for issuing each fractal figure registered in the registration means as a two-dimensional identification code;
Code input means for inputting the issued two-dimensional identification code as image data;
Code recognition means for recognizing a two-dimensional identification code by calculating a fractal dimension by a dimension calculation means for a figure constituting image data input by a code input means;
The fractal figure can be used as an identification code.

(2) A second aspect of the present invention provides an identification code issuing system,
A fractal graphic generation means for generating a fractal graphic using a predetermined algorithm and a predetermined parameter;
Generation control means for generating a plurality of different fractal figures in the fractal figure generation means by changing at least one of the algorithm and the parameters;
Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
Among a plurality of different fractal figures generated by the fractal figure generation means, with respect to a figure having the same fractal dimension calculated by the dimension calculation means, only one of them is selected and a selection process is performed to discard the other. A selection means;
A registration means for registering a fractal figure that has not been discarded by the selection means in association with the fractal dimension;
A code issuing means for issuing each fractal figure registered in the registration means as a two-dimensional identification code;
The fractal figure can be used as an identification code.

(3) A third aspect of the present invention provides an identification code recognition system,
Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
Code input means for inputting, as image data, a two-dimensional identification code expressed using a fractal graphic;
Code recognition means for recognizing a two-dimensional identification code by calculating a fractal dimension by a dimension calculation means for a figure constituting image data input by a code input means;
The fractal figure can be used as an identification code.

(4) According to a fourth aspect of the present invention, in the system according to the first or second aspect described above,
The generation control means controls the fractal figure generation means to generate different fractal figures sequentially in time series,
The sorting means inquires whether or not the same dimension as the fractal dimension calculated for the newly generated fractal figure has already been registered in the registration means. A process of discarding a figure is executed.

(5) According to a fifth aspect of the present invention, in the system according to the first or third aspect described above,
Registration means for registering the correspondence between the value of the fractal dimension and a predetermined identification code is provided, and the code recognition means refers to this correspondence so that the figure constituting the image data is recognized as a specific identification code. It is a thing.

(6) A sixth aspect of the present invention provides an identification code issuance / recognition system,
A fractal graphic generation means for generating a fractal graphic using a predetermined algorithm and a predetermined parameter;
Generation control means for generating a plurality of different fractal figures in the fractal figure generation means by changing at least one of the algorithm and the parameters;
Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
For a plurality of different fractal figures generated by the fractal figure generation means, a figure classification means for classifying according to the value of the fractal dimension calculated by the dimension calculation means;
A registration means for registering a plurality of different fractal figures generated by the fractal figure generation means by belonging to each classification;
A code issuing means for issuing each fractal figure registered in the registration means as a two-dimensional identification code indicating a classification to which the fractal figure belongs;
Code input means for inputting the issued two-dimensional identification code as image data;
Classification recognition means for recognizing the classification indicated by the two-dimensional identification code based on the obtained value by calculating the fractal dimension by the dimension calculation means for the figure constituting the image data input by the code input means; ,
The fractal figure can be used as an identification code.

(7) A seventh aspect of the present invention provides an identification code issuing system,
A fractal graphic generation means for generating a fractal graphic using a predetermined algorithm and a predetermined parameter;
Generation control means for generating a plurality of different fractal figures in the fractal figure generation means by changing at least one of the algorithm and the parameters;
Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
For a plurality of different fractal figures generated by the fractal figure generation means, a figure classification means for classifying according to the value of the fractal dimension calculated by the dimension calculation means;
A registration means for registering a plurality of different fractal figures generated by the fractal figure generation means by belonging to each classification;
A code issuing means for issuing each fractal figure registered in the registration means as a two-dimensional identification code indicating a classification to which the fractal figure belongs;
The fractal figure can be used as an identification code.

(8) An eighth aspect of the present invention provides an identification code recognition system,
Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
Code input means for inputting, as image data, a two-dimensional identification code expressed using a fractal graphic;
Classification recognition means for recognizing the classification indicated by the two-dimensional identification code based on the obtained value by calculating the fractal dimension by the dimension calculation means for the figure constituting the image data input by the code input means; ,
The fractal figure can be used as an identification code.

(9) According to a ninth aspect of the present invention, in the system according to the first or sixth aspect described above,
The code issuing means has a function to issue a duplicate code in which a plurality of two-dimensional identification codes are recorded on the same plane by overlapping a plurality of fractal figures having different colors on the same plane. Have
The code recognizing means or the classification recognizing means extracts only a figure having a specific color and performs recognition processing.

(10) A tenth aspect of the present invention is the system according to the first, third, sixth, or eighth aspect described above,
An optical imaging unit for forming an image of a two-dimensional identification code on a predetermined imaging plane, an image converting unit for converting the image formed on the imaging plane into image data, and code recognition means for the converted image data Alternatively, a device (for example, a camera-equipped mobile phone) including a data transmission unit that transmits to the classification recognition unit is used as the code input unit.

(11) An eleventh aspect of the present invention is the system according to the first to tenth aspects described above,
The dimension calculation means treats the given image as a binary image made up of a graphic part and a background part, divides the binary image into a plurality of cells made up of squares each having a length of r, and has a graphic part inside Cell number calculation processing for determining the number of cells N (r) that can be confirmed to exist, calculation control processing for repeatedly executing this cell number calculation processing while changing the value of r, and a large number of r. And an approximate value determining process for approximately obtaining a value D that satisfies the expression N (r) ∝1 / r ^D based on the value of N (r). The approximate value is a fractal dimension for a graphic included in a given image.

  (12) In a twelfth aspect of the present invention, a program for causing a computer to function as the system according to the first to eleventh aspects described above is prepared, and the program is recorded on a computer-readable recording medium and distributed. It is something that can be done.

(13) A thirteenth aspect of the present invention provides an identification code issuing / recognizing method,
A code generation stage for causing a computer to generate a plurality of fractal figures having different fractal dimensions;
A code issuing stage for issuing each generated fractal figure as a two-dimensional identification code;
A code input stage for inputting the issued two-dimensional identification code as image data;
A dimension calculation stage that causes the computer to calculate the fractal dimension of the figure represented by the input image data;
A code recognition stage for recognizing a two-dimensional identification code based on a fractal dimension obtained by calculation;
The fractal figure can be used as an identification code.

(14) According to a fourteenth aspect of the present invention, in the identification code issuing / recognizing method according to the thirteenth aspect described above,
In the code issuance stage, prepare a table showing the correspondence between the generated fractal graphic, the fractal dimension of the fractal graphic, and the unique identification code,
In the code recognition stage, by referring to this table, a specific identification code corresponding to the fractal dimension calculated for the input image data is obtained, and the input image data is recognized as a specific identification code. is there.

(15) According to a fifteenth aspect of the present invention, there is provided an identification code issuing / recognizing method.
A code generation stage for generating multiple types of fractal figures in a computer;
A code issuing stage for issuing each generated fractal figure as a two-dimensional identification code indicating a predetermined classification;
A code input stage for inputting the issued two-dimensional identification code as image data;
A dimension calculation stage that causes the computer to calculate the fractal dimension of the figure represented by the input image data;
A classification recognition stage for recognizing the classification indicated by the two-dimensional identification code based on the calculated fractal dimension;
The fractal figure can be used as an identification code.

  According to the identification code issuance / recognition system according to the present invention, the fractal dimension that is uniquely determined for the fractal figure is used in association with a specific identification code, so that it is suitable for reading using a general-purpose image capture device. The identification code can be issued and recognized. The fractal figure is a figure having self-similarity, and has a feature that even if an arbitrary part is taken, it is similar to the whole. Therefore, since the image was taken using a digital camera or a mobile phone with a camera, even if it becomes a partial image or a low-resolution image, the fractal dimension recognition is not hindered and correct recognition is possible. Is possible.

  Hereinafter, the present invention will be described based on the illustrated embodiments.

<<< §1. Basic Embodiment >>
FIG. 1 is a block diagram showing a configuration of an identification code issuance / recognition system using a fractal graphic according to a basic embodiment of the present invention. Of the constituent elements shown as individual blocks in the figure, the fractal graphic generation means 10, the generation control means 20, the sorting selection means 30, the dimension calculation means 40, and the registration means 50 are identification codes used for issuing identification codes. It is a component of the issuing system. The code input means 70, the code recognition means 80, and the dimension calculation means 40 are components of an identification code recognition system used for identification code recognition work. The dimension calculation means 40 is a common component used in both the identification code issuing system and the identification code recognition system.

  Here, each component of the identification code issuing system and an identification code issuing procedure will be described first. The fractal graphic generation means 10 is a component having a function of generating a fractal graphic using a predetermined algorithm and predetermined parameters, and the generation control means 20 is an algorithm and parameter used by the fractal graphic generation means 10. It is a component that controls the fractal graphic generation means 10 to generate a plurality of different fractal graphics by changing at least one of them.

  A fractal figure has a self-similar feature that even if only an appropriate part thereof is extracted, it is similar to the whole. In nature, this property can be seen in the shape of coastlines, clouds and trees. In recent years, with the widespread use of computers, research on fractal graphics has been actively conducted, and various types of software for generating fractal graphics using computers, including commercial products, have been developed.

  FIG. 2 is a plan view showing an algorithm for generating a Koch curve, which is a type of fractal graphic. Now, a line segment AB as shown in FIG. 2 (a) is defined, and points C and D that divide the total length into three are taken on this line segment AB. As shown in FIG. When the equilateral triangle CDE is placed and the line segment CD is deleted, a figure composed of an assembly of line segments as shown by a solid line in the figure is formed. Subsequently, when a process equivalent to the above process performed on the line segment AB in FIG. 2A is performed on each of the line segments AC, CE, ED, and DB in FIG. 2B, FIG. A figure consisting of an assembly of line segments as shown in) is created. Here, when a newly generated fine line segment is further subjected to an equivalent process, a figure composed of an assembly of line segments as shown in FIG. If this process is repeated in sequence, a figure consisting of a collection of fine line segments will be generated, but this figure is self-contained to be similar to the whole, even if it takes any small part. It becomes a fractal figure with similarity.

  In FIG. 2, an example of a fractal graphic generation algorithm is shown by taking a simple Koch curve as an example, but there are many other algorithms for generating a fractal graphic by iterative computation of a computer. Depending on the algorithm used, the appearance of the generated fractal figure will vary. Even if the fractal graphic is generated using the same algorithm, the shape varies depending on the parameters used. For example, in the example of the Koch curve shown in FIG. 2, the points C and D are taken at positions where the line segment AB is equally divided into three, but if the positions of these points are changed as parameters, they have different shapes. A fractal figure will be generated. In addition, in the example of FIG. 2, since the equilateral triangle is arranged on the line segment CD, the angle ECD and the angle EDC are 60 °. However, even if this angle is changed as a parameter, it is different. A fractal figure having a shape is generated.

  A plurality of algorithms are prepared for the fractal graphic generation means 10 shown in FIG. 1, and an arbitrary algorithm can be selected by the generation control means 20. Further, the generation control unit 20 has a function of arbitrarily setting parameters used by the fractal graphic generation unit 10. Then, the generation control means 20 performs a process of giving instructions to the fractal graphic generation means 10 to generate a fractal graphic while selecting various algorithms and setting various parameters. As a result, the fractal graphic generation means 10 performs a process of sequentially generating various shapes of fractal graphic.

  If the fractal figure generated in this way is used as a substitute for an identification code such as a conventional barcode, the present inventor performed reading using a general-purpose image capturing device such as a digital camera or a camera-equipped mobile phone. In some cases, I got the idea that it would be possible to recognize without any problems. This is because the fractal figure is a figure having self-similarity, and even if an appropriate part is taken, it has a feature that it is similar to the whole.

  For example, let us consider a case where a fractal graphic as shown in FIG. 2 (d) is distributed as a product identification code attached to a product. Assume that the purchaser of this product has taken this product identification code with a camera-equipped mobile phone. In this case, a figure as shown in FIG. 2 (d) is captured as image data. At this time, since a part of this figure has gone out of the field of view of the camera, the feature as a fractal figure will not be lost even if it is imported as image data lacking a part of the figure. There will be no hindrance to recognition. In other words, the fractal figure shown in FIG. 2 (d) can be recognized as the same fractal figure, whether it is the whole or only a part thereof. This is not the case with conventional identification codes. For example, in the case of a bar code, if even one bar is missing, correct code recognition cannot be performed. Of course, even if a price tag label or the like hides a part of a barcode, correct recognition cannot be performed. An identification code made of a fractal figure can be recognized without any trouble even if it is partially covered with a price tag label.

  Further, the identification code made of a fractal graphic is not affected by the difference in resolution at the time of image capture. In general, in an image taken with a high-resolution camera, the fine features of the outline can be grasped delicately, whereas in an image taken with a low-resolution camera, the fine portion is crushed and cannot be read. Therefore, when a barcode composed of fine lines is photographed with a low-resolution camera, the correct barcode cannot be recognized from the photographed image. Alternatively, even when a high-resolution camera is used, if a high zoom magnification is set, a delicate image cannot be obtained, and correct barcode recognition cannot be performed. However, if a fractal graphic is used as an identification code, such trouble does not occur. This is because, from the viewpoint of recognizing fractal graphics, there is no difference whether the resolution is high or low. In a fractal graphic, the shape of a fine part is similar to the entire shape, so that the same fractal graphic is recognized as the same fractal graphic regardless of the resolution.

  Another advantage of using a fractal graphic as an identification code is that the fractal graphic itself functions as a design pattern. The barcode that is currently used generally is understood as some kind of identification code, and not as a design design. Rather, the barcode should be an obstacle to the design design of the entire product package. On the other hand, as described above, fractal figures are figures that exist in nature, such as coastline shapes, cloud shapes, and tree shapes, and human visual images are usually called “comfortable patterns”. It should be. Therefore, even if a fractal graphic is printed on the product package as an identification code, it can be easily integrated as a design design of the entire product package. For example, even if a fractal pattern is arranged as the ground pattern of the entire product package, no sense of incongruity occurs.

  By the way, since a fractal graphic is used as an identification code, it must be possible to recognize some code by capturing the fractal graphic as image data. The inventor of the present application has focused on a unique value called “fractal dimension” of a fractal graphic, and has come up with a method of defining a correspondence relationship with a specific identification code using the value of this “fractal dimension”. By this method, the fractal figure can be used as a pattern representing a specific identification code, not as a simple design pattern. In short, the value of the “fractal dimension” should be a parameter indicating the degree of complexity of the fractal graphic, and has a unique value for each fractal graphic. Therefore, when a large number of fractal figures are generated by the fractal figure generating means 10 shown in FIG. 1, each of these fractal figures has a unique “fractal dimension” value.

  The dimension calculation means 40 is a component having a function of calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image. The meaning of the “fractal dimension” and the specific calculation method of the dimension value will be described in §2. However, when arbitrary image data is given to the dimension calculation means 40, the dimension calculation means 40 Based on this algorithm, it has a function of calculating a fractal dimension with a predetermined accuracy and outputting the obtained dimension value. Theoretically, a fractal dimension value between 1 and 2 is given to a two-dimensional figure. In the example shown in FIG. 1, a state in which a dimension value of “1.082” is obtained by giving image data of a specific fractal graphic generated by the fractal graphic generating means 10 to the dimension calculating means 40 is shown. Yes. In this case, the dimension calculation means 40 has a function of calculating a fractal dimension with an accuracy of three digits after the decimal point.

  In the system shown in FIG. 1, a large number of fractal figures generated by the fractal figure generation means 10 are registered in the registration means 50. At this time, each fractal figure is calculated by the dimension calculation means 40. The fractal dimension value is registered in association with a predetermined identification code (for example, product identification code). For example, in the example shown in FIG. 1, a state where three types of fractal figures F1, F2, and F3 are registered in the registration unit 50 is shown. Specifically, the first fractal graphic F1 has a dimension value “1.082” and corresponds to the identification code “AA001”, the second fractal graphic F2 has a dimension value “1.263”, Corresponding to the identification code “AA002”, the third fractal figure F3 has a dimension value “1.294” and corresponds to the identification code “AA003”.

  When the fractal graphic generated by the fractal graphic generation means 10 is registered in the registration means 50, the selection means 30 is used in order to avoid registration of fractal graphics having the same dimension value. It is. As described above, a specific fractal figure has a specific fractal dimension value, and this fractal dimension value should be a parameter indicating the degree of complexity of the fractal figure. If they are the same, different fractal figures may have the same fractal dimension value. In particular, considering that the dimension calculation means 40 calculates the fractal dimension with a predetermined accuracy (accuracy of 3 digits after the decimal point in the example of FIG. 1), the fractals that take the same dimension value within the accuracy range. Of course, there are multiple figures.

  On the other hand, the product identification code or the like usually needs to be a unique identification code. Therefore, in the system shown in FIG. 1, the sorting selection unit 30 performs sorting processing so that dimension values do not overlap at the time of registration. That is, the selection means 30 selects only one of the plurality of different fractal figures generated by the fractal figure generation means 10 for the same fractal dimension calculated by the dimension calculation means 40. The registration unit 50 has a function of performing a selection process for discarding others, and the fractal graphic that has not been discarded by the selection unit 30 is associated with the fractal dimension and the specific identification code. Will be registered.

  More specifically, in the case of the embodiment described here, the generation control means 20 has a function of controlling the fractal figure generation means 10 to sequentially generate different fractal figures in time series. From the fractal graphic generation means 10, new fractal graphics are sequentially sent to the sorting selection means 30. When a new fractal graphic is sent from the fractal graphic generation unit 10, the sorting selection unit 30 causes the dimension calculation unit 40 to calculate a dimension for the fractal graphic, and the same dimension as the calculated fractal dimension is obtained. An inquiry is made as to whether or not the registration means 50 has already been registered. If a fractal graphic of the same dimension has already been registered, a process of discarding a new fractal graphic sent from the fractal graphic generation means 10 is executed. For example, in the case of the illustrated example, the dimension values “1.082”, “1.263”, and “1.294” have already been registered, so if the new dimension values sent from the fractal graphic generation means 10 are new. When the dimension value of the fractal graphic is the same as any one of these, the fractal graphic is discarded in the sorting unit 30.

  If such a process is repeated, a large number of fractal figures having different fractal dimensions are registered in the registration means 50, and each registered fractal figure has a unique identification code. It will be matched. The upper limit value of the total number of fractal figures registered in the registration unit 50 is determined according to the accuracy of the dimension calculation in the dimension calculation unit 40, and increases as the calculation accuracy increases (that is, the number of digits after the decimal point increases. It is possible to increase the number of variations of fractal figures and to increase the number of identification codes to be associated. However, since the accuracy of the dimensional calculation in the dimensional calculation means 40 depends on the resolution of the fractal figure, the calculation precision of the dimensional calculation means 40 is practically considered in consideration of the resolution of the fractal figure to be used. It is necessary to decide.

  However, since the correspondence with the identification code can be defined for a combination of two or more fractal figures, even if there are few variations of the fractal figures, the correspondence with many identification codes is possible depending on the combination. It becomes possible to define relationships. For example, even if there are only 100 fractal figures, there are 100 × 100 = 10,000 combinations of two fractal figures, and there are 1 million combinations of three fractal figures. No trouble will occur.

  The code issuing means 60 is a component that issues each fractal graphic registered in the registration means 50 as a two-dimensional identification code. In the illustrated example, a state in which the fractal figure F1 is issued as the two-dimensional identification code C and attached to the product G is shown. Conceptually, this is the same as attaching the identification code “AA001” (identification code associated with the fractal graphic F1 in the registration means 50) to the product G. As described above, when a combination of a plurality of fractal graphics is used as the two-dimensional identification code, the plurality of fractal graphics may be displayed side by side on the product G.

  The above is the schematic configuration of the identification code issuing system using the fractal graphic according to the present invention. After all, this issuance system is a system having a function of causing a computer to generate a plurality of fractal figures having different fractal dimensions and issuing each generated fractal figure as a two-dimensional identification code.

  Next, each component of the identification code recognition system according to the present invention and the identification code recognition procedure will be described. As described above, the basic components of the identification code recognition system are the code input means 70, the code recognition means 80, and the dimension calculation means 40.

  The code input means 70 is a component having a function of inputting the issued two-dimensional identification code C as image data. As already described, since the two-dimensional identification code C according to the present invention is composed of fractal figures, it is suitable for inputting as image data by photographing with a digital camera or a camera-equipped mobile phone. In this case, a digital camera, a camera-equipped mobile phone, or the like functions as the code input unit 70. Of course, as the code input means 70, a scanner device or the like may be used.

  The code recognition unit 80 is a component that recognizes a two-dimensional identification code by causing the dimension calculation unit 40 to calculate a fractal dimension for a figure constituting the image data input by the code input unit 70. That is, when the image data input by the code input means 70 is given to the dimension calculation means 40, a fractal dimension value for a figure constituting the image data is calculated. Based on this dimension value, identification is performed. The code can be recognized. In this embodiment, since the correspondence between the fractal dimension value and the predetermined identification code is registered in the registration unit 50, the code recognition unit 80 refers to the correspondence in the registration unit 50. As a result, the figure constituting the image data given from the code input means 70 can be recognized as a specific identification code.

  For example, in the case of the example shown in FIG. 1, since the product G has a fractal graphic F1 as a two-dimensional identification code C, the code recognition means 80 is given image data of the fractal graphic F1. become. When the image data of the fractal figure F1 is given to the dimension calculation means 40 to calculate the fractal dimension, a result “1.082” is obtained. On the other hand, as shown in the figure, the registration means 50 is provided with a table indicating the correspondence between the fractal graphic F1, the fractal dimension “1.082” of the fractal graphic F1, and the unique identification code “AA001”. Therefore, the code recognition unit 80 can recognize that the identification code corresponding to the fractal dimension value “1.082” is “AA001” by referring to this table. Eventually, the identification code “AA001” is recognized based on the two-dimensional identification code C attached to the product G.

  In the above-described example, the correspondence between the fractal dimension and the identification code is registered in the registration unit 50. However, the fractal dimension value itself or some code that can be uniquely derived from the fractal dimension value is identified code. It is no longer necessary to register such a correspondence relationship. For example, in the case of the example of FIG. 1, codes “1082”, “1263”, and “1294” obtained by multiplying the fractal dimension values “1.082”, “1.263”, and “1.294” by 1000 are obtained. If it is used as an identification code as it is, there is no need to separately prepare identification codes such as “AA001”, “AA002”, and “AA003”. In this case, the code recognition unit 80 does not need to refer to the registration unit 50 when recognizing the identification code. That is, the target identification code can be obtained by multiplying the fractal dimension value calculated by the dimension calculation means 40 by 1000.

<<< §2. Fractal dimension calculation method >>>
As already described, the “fractal dimension” should be a parameter indicating the degree of complexity of the fractal figure, and the larger the value, the higher the degree of complexity. The term “dimension” is used here because it is closely related to the dimension in the space indicated by the figure. For example, in the case of a one-dimensional fractal graphic (a linear pattern arranged on a one-dimensional straight line), the theoretical maximum value of the fractal dimension is 1, and a two-dimensional fractal graphic (a flat pattern arranged on a two-dimensional plane). In this case, the theoretical maximum value of the fractal dimension is 2. In the case of a three-dimensional fractal figure (a three-dimensional pattern arranged in a three-dimensional space), the theoretical maximum value of the fractal dimension is three.

  The concept of “fractal dimension” is a known concept disclosed in various documents, and its calculation method is also known. However, since the calculation process of the fractal dimension performed by the dimension calculation means 40 is a very important process in practicing the present invention, an example of a specific calculation process of the fractal dimension is briefly described here. Let me state.

  FIG. 3 is a cell division diagram for showing a fractal dimension of a general figure. Here, for convenience of explanation, the concept of fractal dimension will be briefly described with reference to FIG. Consider a case where a figure A as shown in FIG. 3 (a1) and a figure B as shown in FIG. 3 (b1) are present in a square having a side length r = 1. In both cases, the hatched portion is the graphic portion P, the white area is the background portion Q, and the respective graphics A and B are expressed as binary images. When comparing the figures A and B and considering which one is more complicated, it is intuitively possible to recognize that the figure B is more complicated. The “fractal dimension” is a parameter for quantitatively evaluating the complexity of the figure.

  Now, suppose that a square with one side length r = 1 is divided into four and divided into cells each having a square with one side length r = 1/2, as shown in FIGS. 3 (a2) and 3 (b2). A division result as shown is obtained. Similarly, if a square with one side length r = 1 is divided into nine cells, each cell is made up of a square with one side length r = 1/3, as shown in FIGS. 3 (a3) and 3 (b3). Can be obtained. Further, if a square having a side length r = 1 is divided into 16 and divided into cells each having a side length r = 1/4, as shown in FIG. 3 (a4) and FIG. 3 (b4). A division result is obtained.

  Here, each cell is divided into a cell having a slight figure portion P inside and a cell having no figure portion P inside (in other words, a cell in which the whole area in the cell is the background portion Q). ) And to distinguish. In FIG. 3, the cell marked with an asterisk is the latter cell. Focusing on figure A, up to four-divided cells (r = 1, r = 1/2 cells), although the cells marked with an asterisk are 0, nine-divided cells (r = 1/3) The cell marked with an asterisk is 2 in the cell), and the cell marked with an asterisk is 6 in the 16-divided cell (r = 1/4 cell). Although not shown, the number of cells marked with an asterisk increases to 12 in 25-divided cells (r = 1/5 cells). On the other hand, when attention is paid to the figure B, the cells marked with an asterisk are 0 up to 16 divided cells. Although not shown, four cells marked with an asterisk are generated in 25 divided cells (cells with r = 1/5). As can be inferred from this example, when the divided cell is defined with various values of r, the figure with as few stars as possible (in other words, the figure with as many cells without stars as possible) It can be said that the figure has a high degree of complexity.

  Here, when a given binary image is divided into a plurality of cells each consisting of a square having a length of one side, the number of cells that can be confirmed as having a graphic portion P therein is represented as N (r). To do. In the case of the graphic A in the example shown in FIG. 3, N (1) = 1, N (1/2) = 4, N (1/3) = 7, N (1/4) = 10, N (1 / 5) = 13, and in the case of the figure B, N (1) = 1, N (1/2) = 4, N (1/3) = 9, N (1/4) = 16, N (1 / 5) = 21. The result of obtaining a large number of N (r) values by changing the value of r indicates a parameter indicating the complexity of the contour portion of the binary image.

  FIG. 4 is a table showing specific values of N (r) thus obtained. The value of N (r) written in the columns of graphics A and B in this table is the value obtained for graphics A and B shown in FIG. When the value of r is decreased to 1, 1/2, 1/3, 1/4, 1/5,..., the total number of divided cells is naturally 1, 4, 9, 16, 25,. Since it increases, the value of N (r) also tends to increase. The increase rate becomes a parameter indicating the degree of complexity of the contour portion, that is, the “fractal dimension value”. In the table shown in FIG. 4, the value of N (r) written in the column of “two-dimensional MAX figure” is a figure that is theoretically most complicated as a fractal figure on a two-dimensional plane (here, This value is referred to as “two-dimensional MAX graphic”. Similarly, in the table shown in FIG. 4, the value of N (r) written in the column of “one-dimensional MAX graphic” is a figure that is theoretically most complicated as a fractal graphic on a one-dimensional straight line ( Here, it is a value for “one-dimensional MAX graphic”), and the value of N (r) written in the “three-dimensional MAX graphic” column is theoretically a fractal graphic on a three-dimensional solid. Are the values for the most complicated figure (referred to herein as a “three-dimensional MAX figure”).

Now, considering the value of N (r) for a two-dimensional MAX figure, if the value of r decreases to 1, 1/2, 1/3, 1/4, 1/5,. It will be understood that the value increases as 1, 4, 9, 16, 25,... And is expressed as a function of N (r) = 1 / r ² . This is because if the figure is divided into four, the graphic part P exists in all four cells, and if divided into nine, the graphic part P exists in all nine cells. This means that there is a graphic part P, and that no matter how finely it is divided, the complexity is such that the graphic part P always exists in all cells (the maximum complexity for a two-dimensional graphic) ) Is a two-dimensional MAX figure.

Of course, it becomes possible to increase complexity when it becomes a three-dimensional figure. That is, when the value of N (r) for a three-dimensional MAX figure is examined, when the value of r becomes as small as 1, 1/2, 1/3, 1/4, 1/5,. It will be understood that the value increases as 1, 8, 27, 64, 125,..., And is expressed as a function of N (r) = 1 / r ³ . This is because if the original cube is divided into 8 parts, the graphic part P exists in all 8 cells, and if divided into 27 parts, the graphic part P exists in all 27 cells, and if divided into 64 parts, , Which means that there is a graphic part P in all 64 cells, and that no matter how finely it is divided, the complexity is always such that there is a graphic part P in every cubic cell (third order). A figure having the maximum complexity) is a three-dimensional MAX figure.

Conversely, in the case of a one-dimensional MAX figure, when the value of r becomes as small as 1, 1/2, 1/3, 1/4, 1/5,..., The value of N (r) becomes 1, 2, 3, 4, 5,..., And is expressed as a function of N (r) = 1 / r. After all, if the N (r) = 1 / r D becomes function holds, fractal dimension value of the figure will be referred to as D. In the case of the graphic A and the graphic B shown in FIG. 3, the value of N (r) takes a value between 1 / r and 1 / r ² , and the value of the fractal dimension of these graphics is 1-2. Between.

Since the figure A and the figure B shown in FIG. 3 are not fractal figures, the relationship between r and N (r) cannot be expressed by a specific function, but in the case of a theoretical fractal figure, r and N relationship between the (r) can be represented by N (r) = 1 / r D becomes a function, when plotted as a logarithmic graph, a straight line graph as shown in FIG. In the above example, the length of one side of the square including the entire original figure is set to 1, but in a general case where this is an arbitrary value, N (r) ∝1 / r ^D This relationship will hold. Here, if the proportionality constant is K, the equation N (r) = K · r− ^D is established. Therefore, if the logarithm of both sides is taken, the equation log N (r) = − D · log r + log K is obtained. . The graph shown in FIG. 5 shows a function corresponding to this equation. As described above, D in this equation is the value of “fractal dimension”, and corresponds to the slope of the graph shown in FIG.

Eventually, the dimension calculation performed by the dimension calculation means 40 is an operation for obtaining the slope of this graph. Therefore, the dimension calculation means 40 treats the given image as a binary image composed of the graphic portion P and the background portion Q, and divides the binary image into a plurality of cells composed of squares each having a length r. Then, the number-of-cells calculation process for obtaining the number of cells N (r) that can be confirmed that the figure portion P exists inside is repeatedly executed a number of times while changing the value of r, and N (r) obtained for each of a number of r. Value D satisfying the expression N (r) ∝1 / r ^D is approximately obtained, and the approximate value of the obtained value D is obtained as a fractal dimension for a figure included in a given image. The process described above may be performed.

<<< §3. Various modifications >>
Finally, some modifications of the present invention will be described.

(1) Modified example that allows overlapping of fractal dimension values In the basic embodiment described in §1, selection by the selection means 30 is performed so that a figure having the same fractal dimension value is not registered repeatedly. The process was being executed. This is a process necessary when a specific fractal graphic and a specific identification code need to correspond one-to-one. However, depending on the operation mode, there is a case where a specific fractal graphic and a specific identification code do not necessarily correspond one-to-one. FIG. 6 is a block diagram showing a modification suitable for such a case.

  In the modification shown in FIG. 6, a graphic classification means 35 is provided instead of the sorting selection means 30 shown in FIG. 1, and a classification recognition means 85 is provided instead of the code recognition means 80 shown in FIG. . Further, a registration unit 55 is provided instead of the registration unit 50. Other components are the same as those in the basic embodiment shown in FIG. That is, the fractal graphic generation means 10 has a function of generating a fractal graphic using a predetermined algorithm and predetermined parameters, and the generation control means 20 controls the fractal graphic generation means 10 to control a plurality of fractal graphic generation means 10. It serves to generate different fractal figures. Further, the dimension calculation means 40 performs a function of calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image, and the code issuing means 60 issues a two-dimensional identification code C composed of a fractal graphic, The input means 70 functions to input this as image data.

  The difference in the code issuance from the embodiment shown in FIG. 1 is that the figure classification means 35 calculates the fractal dimension values calculated by the dimension calculation means 40 for a plurality of different fractal figures generated by the fractal figure generation means 10. The registration means 55 has a function of registering a plurality of different fractal graphics generated by the fractal graphic generation means 10 by belonging to each classification. is there. As a result, a plurality of fractal figures are registered in the registration unit 55 for one classification. In the registration means 55 of FIG. 6, the classification “C1” is defined corresponding to the dimension value “1.0” of the fractal dimension, and the classification “C2” is defined corresponding to the dimension value “1.1”. A class “C3” is defined corresponding to the dimension value “1.2”, and a plurality of fractal figures are associated with each class.

  In short, the fractal graphic generated by the fractal graphic generation means 10 is assigned to one of the classifications according to the dimension value, and is registered in the registration means 55. A fractal figure will belong. Such classification may be performed so that the fractal dimension value has a predetermined width. For example, assuming that the dimension value calculated by the dimension calculation means 40 is D, if 1.0 ≦ D <1.1, it belongs to the classification “C1”, and if 1.1 ≦ D <1.2, If it is made to belong to the classification “C2”, and if 1.2 ≦ D <1.3, it belongs to the classification “C3”, and the definition as shown in FIG. . The graphic classification means 35 is a component having a function of performing such classification processing. Specifically, for example, such a classification is performed by rounding down the second decimal place of the dimension value D calculated by the dimension calculating means 40, and if the value is 1.0, it is assigned to the class C1. If it belongs to the class C2, if 1.2, it belongs to the class C3, and so on. Alternatively, when the dimension value D is calculated by the dimension calculation means 40, it may be calculated with the first decimal place.

  Eventually, in this modification, the code issuing means 60 issues each fractal graphic registered in the registration means 55 as a two-dimensional identification code C indicating the classification to which the fractal graphic belongs. The two-dimensional identification code C has a meaning as a code indicating classification.

  As a result, the recognition process for the two-dimensional identification code C is also a process for recognizing a specific classification. That is, the classification recognition unit 85 causes the dimension calculation unit 40 to calculate the fractal dimension of the figure constituting the image data input by the code input unit 70, and is indicated by the two-dimensional identification code C based on the obtained value. The process which recognizes the classification which is carried out is performed. For example, in the case of the illustrated example, if the dimension value “1.082” is obtained by the dimension calculation means 40 for the two-dimensional identification code C input by the code input means 70, the classification recognition means 85 will register the registration means 55 , It can be recognized that the two-dimensional identification code C is an identification code indicating the classification “C1”.

  Such classification recognition techniques can be used in various forms in practice. For example, when a lottery is attached to a product, a fractal figure can be used as a display for the lottery. That is, if an arrangement is made such that the classification “C1” corresponds to the third prize, the classification “C2” corresponds to the second prize, and the classification “C3” corresponds to the first prize, the various items attached to the product G If the fractal graphic is read by the code input means 70 and the classification is recognized by the classification recognition means 85, the winning grade of the lottery can be grasped.

(2) Modified example of superimposing the two-dimensional identification code C As described above, the two-dimensional identification code C made of a fractal figure is not necessarily required at the time of recognition, and a part thereof can be recognized. Has a merit. For this reason, it becomes possible to superimpose and display a plurality of two-dimensional identification codes C. For example, the code issuing means 60 issues a duplicate code in which a plurality of two-dimensional identification codes are recorded on the same plane by superimposing a plurality of fractal figures having different colors on the same plane. If the code recognition unit 80 or the classification recognition unit 85 has a function of extracting only a figure having a specific color and performing a recognition process, a plurality of identification code issuance and recognition processes Is possible.

  Specifically, for example, it is assumed that the first fractal graphic F1 is printed in yellow on the product G and the second fractal graphic F2 is printed in blue on the same product G. In this case, even if both fractal graphics F1 and F2 are printed in the same region on the product G, the shapes of the two graphics are different, so that some of them overlap but some do not overlap. The overlapping part will exhibit a composite color such as green, for example, but the non-overlapping part remains the original yellow or blue. Therefore, if the recognition process for only the yellow part and the recognition process for only the blue part are executed during the recognition process by the code recognition unit 80 or the classification recognition unit 85, the first fractal figure F1 is shown. Both the recognition of the first identification code and the recognition of the second identification code indicated by the second fractal figure F2 can be performed.

(3) Modified Example of Transmitting Image Using Mobile Phone As described above, the identification code using the fractal figure according to the present invention is suitable for photographing with a digital camera, a mobile phone with a camera, or the like. In particular, in the case of shooting with a camera-equipped mobile phone, the shot image data can be transmitted via a communication network, so that the usage forms of the identification code are further expanded. For example, when the identification code using the fractal graphic is used as a lottery attached to the product as in the modification (1) described above, the purchaser of the product uses the camera-equipped mobile phone to display the fractal graphic functioning as the lottery. After taking a picture, it is also possible to send a photographed image via a communication network and perform a gift exchange procedure.

  Such a use example can be said to be an example in which a camera-equipped mobile phone is used as the code input means 70 in the system shown in FIG. In this case, the transmission of the image data from the code input unit 70 to the code recognition unit 80 is performed by communication using a mobile phone.

  In addition, although the example using the specific apparatus called a camera-equipped mobile phone was described here, such a use form is not necessarily limited to the example using a camera-equipped mobile phone. In short, as the code input means 70, an optical imaging unit that forms an image of a two-dimensional identification code on a predetermined imaging surface, an image conversion unit that converts the image formed on this imaging surface into image data, A device including a data transmission unit that transmits image data to the code recognition unit 80 or the classification recognition unit 85 may be used.

(4) System Configuration Using Computer The ID code issuing / recognizing system using fractal graphics according to the present invention has been described so far with reference to the block diagram shown in FIG. 1 or FIG. Such a system is practically configured as a system using a computer. Therefore, each component shown as an individual block in these block diagrams should be realized by using a computer or its peripheral devices, and the function of each component is realized by a computer program. It should be.

It is a block diagram which shows the structure of the identification code issuing / recognition system using the fractal figure which concerns on fundamental embodiment of this invention. It is a top view which shows the production | generation algorithm of the Koch curve which is a kind of fractal figure. It is a cell division figure for showing the fractal dimension about a general figure. It is a table | surface for demonstrating a fractal dimension. It is a graph for demonstrating a fractal dimension. It is a block diagram which shows the structure of the identification code issuing / recognition system using the fractal figure which concerns on another embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fractal figure generation means 20 ... Generation control means 30 ... Sorting selection means 35 ... Graphic classification means 40 ... Dimension calculation means 50 ... Registration means 55 ... Registration means 60 ... Code issuing means 70 ... Code input means 80 ... Code recognition means 85 ... Classification recognition means C ... Two-dimensional identification codes F1 to F3 ... Fractal figure G ... Product P ... Figure part Q ... Background part r ... Length of one side of square cell

Claims (15)

A fractal graphic generation means for generating a fractal graphic using a predetermined algorithm and a predetermined parameter;
Generation control means for generating a plurality of different fractal figures in the fractal figure generation means by changing at least one of the algorithm and the parameter;
Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
Among a plurality of different fractal figures generated by the fractal figure generating means, for a figure having the same fractal dimension calculated by the dimension calculating means, a selection process for selecting only one and discarding the other is performed. Sorting selection means to be performed;
Registration means for registering a fractal figure that has not been discarded by the selection selecting means in association with the fractal dimension;
Code issuing means for issuing each fractal figure registered in the registration means as a two-dimensional identification code;
Code input means for inputting the issued two-dimensional identification code as image data;
Code recognition means for recognizing a two-dimensional identification code by calculating a fractal dimension by the dimension calculation means for the figure constituting the image data input by the code input means;
An identification code issuance / recognition system using a fractal graphic. A fractal graphic generation means for generating a fractal graphic using a predetermined algorithm and a predetermined parameter;
Generation control means for generating a plurality of different fractal figures in the fractal figure generation means by changing at least one of the algorithm and the parameter;
Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
Among a plurality of different fractal figures generated by the fractal figure generating means, for a figure having the same fractal dimension calculated by the dimension calculating means, a selection process for selecting only one and discarding the other is performed. Sorting selection means to be performed;
Registration means for registering a fractal figure that has not been discarded by the selection selecting means in association with the fractal dimension;
Code issuing means for issuing each fractal figure registered in the registration means as a two-dimensional identification code;
An identification code issuance system using a fractal graphic. Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
Code input means for inputting, as image data, a two-dimensional identification code expressed using a fractal graphic;
Code recognition means for recognizing a two-dimensional identification code by calculating a fractal dimension by the dimension calculation means for the figure constituting the image data input by the code input means;
An identification code recognition system using fractal graphics, characterized by comprising: The system according to claim 1 or 2,
The generation control means controls the fractal figure generation means to generate different fractal figures sequentially in time series,
The sorting means inquires whether or not the same dimension as the fractal dimension calculated for the newly generated fractal figure has already been registered in the registration means. An identification code issuance / recognition system or identification code issuance system using a fractal graphic, wherein a process of discarding the graphic is executed. The system according to claim 1 or 3,
A function for recognizing a figure constituting image data as a specific identification code by providing registration means for registering a correspondence relation between a value of a fractal dimension and a predetermined identification code, and by referring to the correspondence relation. An identification code issuance / recognition system or an identification code recognition system comprising: A fractal graphic generation means for generating a fractal graphic using a predetermined algorithm and a predetermined parameter;
Generation control means for generating a plurality of different fractal figures in the fractal figure generation means by changing at least one of the algorithm and the parameter;
Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
For a plurality of different fractal figures generated by the fractal figure generating means, figure classification means for classifying according to the value of the fractal dimension calculated by the dimension calculating means;
A plurality of different fractal figures generated by the fractal figure generating means, and a registration means for registering them belonging to each classification;
A code issuing means for issuing each fractal graphic registered in the registration means as a two-dimensional identification code indicating a classification to which the fractal graphic belongs;
Code input means for inputting the issued two-dimensional identification code as image data;
Classification recognition for causing a fractal dimension to be calculated by the dimension calculation means for a figure constituting the image data input by the code input means, and for recognizing the classification indicated by the two-dimensional identification code based on the obtained value Means,
An identification code issuance / recognition system using a fractal graphic. A fractal graphic generation means for generating a fractal graphic using a predetermined algorithm and a predetermined parameter;
Generation control means for generating a plurality of different fractal figures in the fractal figure generation means by changing at least one of the algorithm and the parameter;
Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
For a plurality of different fractal figures generated by the fractal figure generating means, figure classification means for classifying according to the value of the fractal dimension calculated by the dimension calculating means;
A plurality of different fractal figures generated by the fractal figure generating means, and a registration means for registering them belonging to each classification;
A code issuing means for issuing each fractal graphic registered in the registration means as a two-dimensional identification code indicating a classification to which the fractal graphic belongs;
An identification code issuance system using a fractal graphic. Dimension calculation means for calculating a fractal dimension with a predetermined accuracy for a graphic included in a given image;
Code input means for inputting, as image data, a two-dimensional identification code expressed using a fractal graphic;
Classification recognition for causing a fractal dimension to be calculated by the dimension calculation means for a figure constituting the image data input by the code input means, and for recognizing the classification indicated by the two-dimensional identification code based on the obtained value Means,
An identification code recognition system using fractal graphics, characterized by comprising: The identification code issuance / recognition system according to claim 1 or 6,
The code issuing means has a function to issue a duplicate code in which a plurality of two-dimensional identification codes are recorded on the same plane by overlapping a plurality of fractal figures having different colors on the same plane. Have
An identification code issuance / recognition system, wherein the code recognition means or the classification recognition means extracts only a figure having a specific color and performs recognition processing. The system according to claim 1, 3, 6 or 8.
The code input means includes an optical imaging unit that forms an image of a two-dimensional identification code on a predetermined imaging plane, an image conversion unit that converts the image formed on the imaging plane into image data, and the image data An identification code issuance / recognition system or an identification code recognition system, comprising: a data transmission unit that transmits data to a code recognition unit or a classification recognition unit. The system according to any one of claims 1 to 10,
The dimension calculation means treats the given image as a binary image composed of a graphic part and a background part, divides the binary image into a plurality of cells each consisting of a square having a length of one side, and internally contains the graphic A cell number calculation process for obtaining the number of cells N (r) that can be confirmed to exist, a calculation control process for repeatedly executing this cell number calculation process while changing the value of r, and a large number of r. And an approximate value determining process for approximately obtaining a value D that satisfies the expression N (r) ∝1 / r ^D based on the value of N (r), and the obtained value D An identification code issuance / recognition system, an identification code issuance system, or an identification code recognition system, characterized in that the approximate value is a fractal dimension for a graphic included in a given image.   The program for functioning a computer as a system in any one of Claims 1-11, or the computer-readable recording medium which recorded the said program. A code generation stage for causing a computer to generate a plurality of fractal figures having different fractal dimensions;
A code issuing stage for issuing each generated fractal figure as a two-dimensional identification code;
A code input step of inputting the issued two-dimensional identification code as image data;
A dimension calculation step for causing a computer to calculate a fractal dimension for a figure represented by the input image data;
A code recognition stage for recognizing the two-dimensional identification code according to a fractal dimension obtained by calculation;
An identification code issuance / recognition method using a fractal figure characterized by comprising: The method of claim 13, wherein
In the code issuance stage, prepare a table showing the correspondence between the generated fractal graphic, the fractal dimension of the fractal graphic, and the unique identification code,
In the code recognition stage, by referring to the table, a specific identification code corresponding to the fractal dimension calculated for the input image data is obtained, and the input image data is recognized as the specific identification code. ID code issuance / recognition method using fractal graphics. A code generation stage for generating multiple types of fractal figures in a computer;
A code issuing stage for issuing each generated fractal figure as a two-dimensional identification code indicating a predetermined classification;
A code input step of inputting the issued two-dimensional identification code as image data;
A dimension calculation step for causing a computer to calculate a fractal dimension for a figure represented by the input image data;
A classification recognition stage for recognizing the classification indicated by the two-dimensional identification code based on the fractal dimension obtained by calculation;
An identification code issuance / recognition method using a fractal figure characterized by comprising: