JP2017054560A - Two-dimensional code, two-dimensional code generation method, two-dimensional code generation device, program, and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-dimensional code having a redundant structure in an area where data is embedded, a two-dimensional code generation method for generating the two-dimensional code, a two-dimensional code generation device, a program, and a recording medium.SOLUTION: In a two-dimensional code constituted by a model number, a mask pattern, error correction level, embedded data (a data code word) and a filler code word (and further an error correction word), secret information is embedded as metadata into a plurality of segments constituting the data code word, and by constitution positions of the segments, several module patterns can be generated.SELECTED DRAWING: Figure 5

Description

  In particular, the present invention relates to a two-dimensional code, a two-dimensional code generation method, a two-dimensional code generation device, a program, and a storage medium that are suitable for storing confidential information.

  In recent years, a two-dimensional code represented by a QR code (registered trademark) is used for authentication having a monetary value due to diversified uses such as an electronic ticket. On the other hand, there are cases where two-dimensional codes are used, such as forging a two-dimensional code including a malicious URL and pasting it on another two-dimensional code to lead to a phishing site.

  However, general two-dimensional codes do not take countermeasures against forgery and duplication, and development of a technique for preventing forgery and duplication is required. As a means for preventing forgery of the two-dimensional code, there is a method of encrypting stored data. However, when these two-dimensional codes are read by a general decoder, the presented information is an enumeration of characters whose meaning is unknown. Therefore, there is a problem of giving distrust to the user.

  A method of embedding confidential information in a two-dimensional code padding code has also been proposed (see, for example, Patent Document 1). The data length of the two-dimensional code is determined by the model number. When the size of the data to be embedded is smaller than the data length, the padding code is embedded in the missing part. By replacing the padding code with data to be concealed, it is possible to embed concealment information that cannot be read by a general decoder in a two-dimensional code. However, in this method, since the padding code is the secret information, the secret information can be easily extracted when it is known.

  On the other hand, the spread of two-dimensional codes is rapidly progressing, and there is a tendency for visual incentives to decrease as advertising media. For this reason, in recent years, in order to improve the visual incentive, a highly decorative two-dimensional code in which a photograph or an illustration is incorporated inside the two-dimensional code has been proposed. As described above, by enhancing the decorativeness of the two-dimensional code, it is possible to easily identify the information stored in the two-dimensional code before reading, or to improve the visibility and produce the originality.

  However, when a photograph or illustration is incorporated, the information of the incorporated part is concealed, and therefore it is necessary to perform decoding using an error correction function when reading a two-dimensional code. As described above, since the size and arrangement position of photographs and illustrations are limited, it is necessary to optimize the position where the photographs and illustrations are arranged on the two-dimensional code so as to achieve both decoration and readability. For this reason, the method of changing the module pattern is restricted, such as controlling the padding codeword area or changing the error correction word area, and the module pattern in the area where data is embedded is changed. It was difficult.

JP 2012-89177 A JP 2013-25475 A

  In view of the above-described problems, the present invention provides a two-dimensional code having a redundant structure in an area where data is embedded, a two-dimensional code generation method for generating the two-dimensional code, a two-dimensional code generation device, a program, and a storage medium. It is intended to provide.

  The two-dimensional code of the present invention is a two-dimensional code having a code word in which data is embedded by being divided into a plurality of segments, and includes a segment structure for constituting a module pattern expressing a specific shape It is characterized by.

  The two-dimensional code generation method of the present invention relates to an input process for inputting data, confidential information and an image as public information, and generation of a cell arrangement pattern, and a segment corresponding to the confidential information storing the data is generated. A solution candidate generation step of generating a two-dimensional code in which the data is encoded as a solution candidate using a plurality of components including the component as variables, and the solution candidate generated in the solution candidate generation step is similar to the image A solution candidate evaluation step for evaluating whether or not the plurality of components are included in the solution candidate generation step according to the evaluation in the solution candidate evaluation step. A new solution candidate based on the solution candidate is generated, and in the solution candidate evaluation step, the new solution candidate generated in the solution candidate generation step is evaluated. .

  The two-dimensional code generation device of the present invention relates to generation of a cell arrangement pattern, an input unit for inputting data as public information, confidential information and an image, and a segment corresponding to the confidential information for storing the data. A solution candidate generation unit that generates a two-dimensional code obtained by encoding the data as a solution candidate using a plurality of components including the component as variables, and a solution candidate generated by the solution candidate generation unit is similar to the image A solution candidate evaluation unit that evaluates whether or not the solution candidate is evaluated based on at least one objective function, wherein the solution candidate generation unit is based on the plurality of components according to the evaluation by the solution candidate evaluation unit A new solution candidate is generated, and the solution candidate evaluation unit evaluates the new solution candidate generated by the solution candidate generation unit.

  The program of the present invention causes a computer to execute each step of the two-dimensional code generation method.

  The storage medium of the present invention stores the program.

  According to the present invention, by having a redundant structure in an area where data is embedded, confidential information cannot be easily read, and decorativeness can be improved.

It is a block diagram which shows the hardware structural example of the two-dimensional code production | generation apparatus which concerns on embodiment of this invention. It is a block diagram which shows the function structural example of the two-dimensional code production | generation apparatus which concerns on embodiment of this invention. It is a figure which shows the example of a data structure of a general two-dimensional code. It is a figure which shows the structural example of a general segment. It is a figure which shows the structural example of the segment which gave the redundancy in embodiment of this invention. In embodiment of this invention, it is a figure which shows the example of a structure of a segment at the time of embedding confidential information in a segment. In embodiment of this invention, it is a figure which shows the other structural example of a segment at the time of embedding confidential information in a segment. 5 is a flowchart illustrating an example of a processing procedure for generating a plurality of patterns of two-dimensional codes as an initial group in the embodiment of the present invention. It is a figure which shows the list of error correction levels. 6 is a flowchart illustrating an example of a processing procedure for generating a two-dimensional code output by a genetic algorithm in the embodiment of the present invention. It is a figure explaining the target area | region, boundary area | region, and background area | region of the image input. It is a figure explaining Genotype and Phenotype. It is a figure which shows an example of the two-dimensional code of the pattern similar to the two-dimensional code and illustration which affixed the illustration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, description will be made with reference to a QR code which is a kind of two-dimensional code.

FIG. 1 is a block diagram illustrating a hardware configuration example of a two-dimensional code generation device 100 according to the present embodiment.
In FIG. 1, a CPU 101 controls the entire two-dimensional code generation apparatus 100, reads a program stored in a ROM 103 when necessary, expands it in a RAM 102, and executes processing according to the present embodiment. The input device 104 can be loaded with a removable recording medium such as a memory card, and inputs data to be embedded in a two-dimensional code and confidential information, or inputs a photograph or illustration to be formed as a cell pattern.

  The operation unit 105 is an operation member that inputs a command in accordance with a user operation. The storage device 106 is a hard disk, for example, for storing data. The image display device 107 is, for example, a liquid crystal display, and displays a warning message indicating that a two-dimensional code cannot be generated, or displays a menu screen for setting a two-dimensional code condition or the like. A network interface card (NIC) 108 is an interface for exchanging data with other information devices via the LAN 110. The main bus 109 is a bus for connecting the above-described components.

FIG. 2 is a block diagram illustrating a functional configuration example of the two-dimensional code generation device 100 according to the present embodiment.
In FIG. 2, a data input unit 201 inputs data (character string) to be embedded in a two-dimensional code from the input device 104 or an external device via the LAN 110. When the confidential information is embedded in the two-dimensional code, the confidential information is also input.

  The solution candidate generation unit 202 generates a code word and metadata from the input character string and confidential information, and uses a data code word, a model number, an error correction level, a mask pattern, a padding code word, and the like as a variable as a two-dimensional code. Are generated and stored in the solution candidate storage unit 206. In the present embodiment, confidential information can be embedded as metadata by adopting a redundant segment structure in the data code word. This redundant segment structure will be described later. In the present embodiment, the detailed description will be given later, but secret information is stored from a plurality of such two-dimensional codes by a genetic algorithm and a two-dimensional code reflecting a desired photograph or illustration is generated. Like that.

  The image input unit 203 inputs image data such as photographs and illustrations from the input device 104 or an external device via the LAN 110. The solution candidate evaluation unit 204 evaluates the two-dimensional code using a genetic algorithm by comparing the two-dimensional code stored in the solution candidate storage unit 206 with the image data input by the image input unit 203. . The output unit 205 outputs the generated two-dimensional code.

FIG. 3 is a diagram illustrating a data structure example of a general two-dimensional code.
As shown in FIG. 3, the data of the two-dimensional code is composed of a model number, a mask pattern, an error correction level, data to be embedded (data code word), and a padding code word (further including an error correction word). The data to be embedded is further composed of a plurality of segments, which are divided according to modes such as a numeric mode and a kanji mode.

  For example, as shown in FIG. 4, when the information “encoding test dummyURL-kadai.jp” is embedded in the two-dimensional code, the 8-character “encoding test” information in katakana is embedded in segment 1, In segment 2, information of 17 characters “dummyURL-kadai.jp” in alphabetical notation is embedded. When the confidential information is embedded in these segments, the information of each segment can be read even by a general decoder, so that the confidential information is easily obtained.

FIG. 5 is a diagram showing an example of a segment structure with redundancy in the present embodiment.
In this embodiment, confidential information is embedded as segment metadata (mode indicator, ECI mode indicator, ECI allocation number, etc.). In this case, in a general decoder, the segment metadata is only used for the advantage of decoding, and does not appear in the final decoding result. Basically, the desired confidential information cannot be expressed by the segment metadata simply by encoding the public information by a general procedure. In the present embodiment, a redundant segment structure that is originally unnecessary is generated so that desired confidential information matches metadata. For this purpose, for example, a character string that should normally be represented by one segment is intentionally divided into two segments, or an empty segment with zero characters that does not actually contain any information as shown in FIG. It is realized by including.

FIG. 6 is a diagram illustrating an example of the structure of a segment when confidential information is embedded in the segment.
In the structure shown in FIG. 6, the upper part shows segment elements, the middle part shows bits, and the lower part shows confidential information. The segment 1 with 0 characters shown in FIG. 6 has an “8-bit byte” mode and a “Kanji” mode, and a mode indicator indicating these modes represents confidential information. On the other hand, confidential information is not embedded in the data portion embedded as public information.

FIG. 7 is a diagram illustrating another example of the structure of the segment when the confidential information is embedded in the segment.
In the example shown in FIG. 7, the character number indicator represents the confidential information, and by connecting the segment number character number indicator “101”, the segment 2 character number indicator “010”, and the subsequent character number indicator, The confidential information “1010100...” Is represented. The number of bits of the character number indicator uses about the lower 2 to 3 bits of the character number indicator.

  As described above, in the present embodiment, a data structure having redundancy is provided by switching an originally unnecessary segment or providing a segment with 0 characters. On the other hand, it is also possible to generate a two-dimensional code including a module pattern similar to a desired photograph or illustration by using data (data code word) embedded by giving redundancy to a segment as a variable.

  When a photograph or illustration is incorporated, the information of the incorporated part is concealed, and therefore it is necessary to perform decoding using an error correction function when reading a two-dimensional code. As described above, since the size and arrangement position of photographs and illustrations are limited, it is necessary to optimize the position where the photographs and illustrations are arranged on the two-dimensional code so as to achieve both decoration and readability. Therefore, in this embodiment, in addition to module patterns such as two-dimensional code padding code words and error correction words, which are the design variables in Patent Document 2, the structure of the data code word segment is added as a design variable. A combination of these values is adjusted to form a module pattern similar to a photograph or illustration, thereby ensuring decoration and readability.

FIG. 8 is a flowchart illustrating an example of a processing procedure in which the solution candidate generation unit 202 generates a plurality of patterns of two-dimensional codes as an initial group.
First, in step S801, the process waits until an instruction for generating a two-dimensional code and character string data as public information are input from the data input unit 201. When character string data is input, a code word is generated in step S802 based on the input character string. At this time, the data code word is generated by the following procedure when confidential information is input.

  In the present embodiment, two types of data code words are generated: a pattern in which the mode indicator as shown in FIG. 6 represents confidential information and a pattern in which the character number indicator as shown in FIG. 7 represents confidential information. be able to. In addition to this, it is also possible to use the segment with 0 characters, for example, to set the non-empty segment to 1, and set the empty segment to 0, and represent the confidential information by the permutation of the segments. Then, when determining a combination in step S805 described later, one of these number patterns is selected.

  First, a method for generating a pattern in which the mode indicator represents confidential information will be described. The mode indicator includes an “8-bit byte” mode, a “kanji” mode, a “numeric” mode, and an “alphanumeric” mode, which are associated with confidential information according to the appearance order of these modes. At this time, depending on the arrangement of the character types of the public information embedded in the data part, the desired confidential information may not be embedded. In this case, a segment (empty segment) having 0 characters is inserted.

First, a bit string of secret information having a length of n is divided every two bits to obtain 2-bit pairs of permutations B ₁ , B ₂ ,..., B _{[n / 2]} . Then, encoded by a general method public information, obtain segment sequence S _1, S _2, · · ·, a S _N. Next, B _i and S _i are compared in order from i = 1, and it is determined whether or not the mode indicators match. Only when they do not match, an empty segment is added to S _i. to correspond the mode indicator of its S _i to a mode indicator for the B _i. When i = [n / 2] is reached by the above procedure, a bit string representing the end of the confidential information is embedded.

Next, a method for generating a pattern in which the character number indicator represents confidential information will be described. In the following description, an example using the lower 2 bits of the character number indicator will be described. First, the maximum number of characters 2 ^p to be encoded in the same character mode is determined, and the bit sequence of the confidential information to be embedded is divided into p bits and converted into permutations B1, B2,..., B [n / p] of p bit sets. To do. Then, i indicating the bit set of the confidential information of interest and l indicating the segment of interest are initialized to 1.

Next, the mode indicator is determined from the noticed character x in the public information of the segment l. Then, a value d obtained by adding l to a value obtained by converting B _i into a decimal number is calculated. Next, if the public information can be encoded in the same mode from the x character to the x + d character, a segment l composed of the d character is generated. Then, 1 is added to i and l, and d is added to x. When i reaches [n / p], a bit string representing the end of the confidential information is embedded. On the other hand, if i <[n / p], the above procedure is repeated.

  On the other hand, if the public information cannot be encoded in the same mode from the x character to the x + d character, the segment l is generated using characters that can be continuously encoded (referred to as d ′ character). In this case, the confidential information is not embedded, and d ′ is added to x, and the procedure returns to the above-described procedure. When all the public information has already been encoded, the remaining confidential information is encoded using a method for generating a pattern in which the mode indicator represents the confidential information.

  Next, in step S803, a mode indicator and a character number indicator are added to the head of the generated code word. In step S804, a termination bit is added to the end of the generated code word.

  Next, in step S805, a combination of a data code word, an error correction level, a mask pattern, a model number, and a padding code word is set at random. At this time, the combination once applied is not selected again. Further, as shown in FIG. 9, the error correction level can be set in four stages of L, M, Q, and H. Further, when the two-dimensional code is used for a printed matter or an article, the initial setting may be set to only two stages of Q and H in order to increase the error correction function. Good.

  Next, in step S806, the padding code word set in step S805 is generated and added behind the end bit assigned in step S804. Note that the length of the padding code word is determined based on the model number and error correction level of the two-dimensional code. In addition, when a residual code word or a residual bit is necessary depending on the model number, a residual code word or a residual bit is added. Then, an error correction code word having the set error correction level is added. Here, the error correction code word is determined by the data code word, the error correction level, the model number, the code word of the input character string, and the padding code word. Therefore, the information of these five elements can be changed by changing the error correction code word. In this embodiment, since the error correction level, the model number, and the like are handled as design variables in this way, the cell arrangement pattern in the error correction codeword area can also be changed. Next, in step S807, the bit string generated up to step S806 is divided into blocks, and an RS code is generated in each block.

  Next, in step S808, the generated code word is arranged on the symbol of the model number set in step S805. In the present embodiment, it is assumed that two colors of white and black are used as the cell color in order to facilitate binarization and ensure readability. In step S809, mask processing is performed according to the mask pattern set in step S805. In step S810, the format information and the model number information are arranged at predetermined positions on the symbol of the two-dimensional code, and a two-dimensional code as an initial group is generated.

  Next, in step S811, it is determined whether a predetermined number of two-dimensional codes have been obtained. If the predetermined number of two-dimensional codes are not obtained as a result of the determination, the process returns to step S805, and data code words, error correction levels, mask patterns, model numbers, and padding code words are set by different combinations. On the other hand, when a predetermined number of two-dimensional codes are obtained, the processing by the initial group generation unit 202 is terminated. Note that the number of two-dimensional codes necessary for the initial population is determined by parameters used in a genetic algorithm described later.

  Next, a method for generating a two-dimensional code reflecting the shape of a photograph or an illustration using a genetic algorithm based on the evaluation of the solution candidate evaluation unit 204 will be described. When the cell arrangement pattern is changed so as to reflect the shape of the photograph or illustration, the data inside the two-dimensional code is changed, so that the readability is lowered. Therefore, in order to change the cell arrangement pattern while maintaining readability, it is necessary to change the internal configuration data of the two-dimensional code.

  Therefore, in the present embodiment, the error correction level, mask pattern, model number, padding code word, and position and number of empty segments in the data code word, and presence / absence of non-empty segment division, which affect the cell arrangement pattern, as constituent elements Are used as design variables of the genetic algorithm, and a two-dimensional code reflecting the input photograph or illustration is generated by the genetic algorithm.

FIG. 10 is a flowchart illustrating an example of a processing procedure in which the solution candidate evaluation unit 204 evaluates a solution candidate of a two-dimensional code using a genetic algorithm.
First, in step S1001, image data such as a photograph or an illustration is input from the image input unit 203.

  Next, in step S1002, the solution candidate evaluation unit 204 compares the two-dimensional code stored in the solution candidate storage unit 206 with the image data input in step S1001, and the following equation (1) and equation: The fitness Q (C) indicating the similarity is calculated by (2).

  Here, O (x, y) is an actual gradation value in the two-dimensional code, and T (x, y) is an ideal gradation value as an output two-dimensional code. H and W represent the numbers of vertical and horizontal pixels, respectively. In the present embodiment, the threshold ε is set to a value that is small enough to repeat generation and evaluation of solution candidates until they are similar to the input image, and to be regarded as similar.

Further, ω represents a gradation value in the weighted image and is a value calculated from the input image. As shown in FIG. 11, the input image is divided into a target area 1101, a boundary area 1102, and a background area 1103. The method of calculating the gradation value omega differs by these regions, the gradation value omega _target at the target region 1101, the tone value omega _back of a gray level value of omega _border and background region 1103, in the boundary region 1102, It is calculated by the following equation (3).

Here, S _all is the area of the two-dimensional code, and S _target is the area of the target region 601 to be mainly expressed in the image. S _back is the area of the other background region 1103.

  Next, in step S1003, the solution candidate evaluation unit 204 reads two two-dimensional codes at random from the two-dimensional codes stored in the solution candidate storage unit 206. Then, the child two-dimensional code generated immediately before by crossover and mutation in step S1004 to be described later is read from the solution candidate storage unit 206. Then, the two-dimensional code having the highest fitness is selected from the four of the two-dimensional codes of the child and the read two-dimensional codes, and one two-dimensional code is selected by roulette. Here, when one two-dimensional code is selected by the roulette, the specific gravity is set higher in the order of higher fitness, and the two-dimensional code with higher fitness is selected with higher probability.

  Next, in step S1004, the solution candidate generation unit 202 uses the two two-dimensional codes selected in step S1003 as parents, and generates a child individual by crossover. Then, 3% mutation is caused in all genes (data code word, error correction level, mask pattern, model number and padding code word) of the generated child individual.

FIG. 12 is a diagram for explaining Genotype and Phenotype.
In the crossover and mutation in step S1004, as shown in FIG. 12, the data code word, error correction level, mask pattern, model number, and padding code word are manipulated expressed in Genotype. In this case, the error correction level, the mask pattern, and the model number are fixed lengths, which are 2 bits, 3 bits, and 6 bits, respectively. On the other hand, the padding code word has a variable length because it depends on the model number, the error correction level, and the number of characters of the embedded data. As a method of crossover, a child individual is generated using uniform crossover. In the mutation, the bit is inverted with a probability of 3% for each bit as a design variable. In step S <b> 1005, the solution candidate generation unit 202 encodes the generated child individual into a two-dimensional code that is a Phenotype and stores it in the solution candidate storage unit 206.

  Next, in step S1006, the solution candidate evaluation unit 204 determines whether or not a two-dimensional code having a fitness exceeding a predetermined value is obtained as a result of repeating the genetic manipulation. As a result of this determination, if a two-dimensional code having a fitness level exceeding a predetermined value is obtained, it is regarded as being similar to the input image. In step S1007, the two-dimensional code is output from the output unit 205, and the process is performed. finish. As an output method, a two-dimensional code that is a solution candidate may be displayed on the image display device 107 or may be transmitted to an external device via the LAN 110.

  On the other hand, as a result of the determination in step S1006, if a two-dimensional code having a fitness level exceeding a predetermined value is not obtained, it is regarded that they are not similar, and the process returns to step S1002 and the process is repeated until a desired two-dimensional code is obtained. . Thereafter, in step S1002, an adaptive value may be calculated only for a two-dimensional code whose fitness is not calculated, such as a child two-dimensional code.

  FIG. 13A is a diagram illustrating an example of a two-dimensional code pasted with characters, and FIG. 13B is a diagram illustrating an example of a two-dimensional code generated by the method according to the present embodiment. As shown in FIG. 13, a two-dimensional code can be generated with a pattern similar to “2” by the method according to the present embodiment.

  As described above, according to this embodiment, a data code word, an error correction level, a mask pattern, a model number, and a padding code word are used as variables to generate a two-dimensional code that most reflects a photograph or illustration by a genetic algorithm. You can also.

  In the present embodiment, a two-dimensional code reflecting a photograph or an illustration is generated by a genetic algorithm, but other algorithms may be used as long as the algorithm repeats generation and evaluation of solution candidates. As an algorithm to optimize by generating and evaluating candidate solutions by trial and error in this way, in addition, a single point search algorithm such as a random method, a simplex method, a hill climbing method, an annealing method, a tabu search, or the like, Examples include multi-point search algorithms such as genetic algorithms, particle swarm optimization, and ant colony optimization.

  In the present embodiment, a plurality of two-dimensional codes of the initial group are generated. However, depending on the type of algorithm, it may not be necessary to generate a two-dimensional code of the initial group. When the generation and evaluation of solution candidates are repeated using such an algorithm, it is not necessary to generate a plurality of two-dimensional codes as an initial group by the processing shown in FIG.

  In this embodiment, the similarity to the target illustration or the like is used as the objective function. However, the similarity to the target illustration or the like is used as the first objective function and the module pattern evaluation (adjacent rows / columns of the same color). Multi-objective optimization is performed by setting the module, the same color module block, the light / dark pattern of 1: 1: 3: 1: 1 in the rows and columns, the ratio of the dark module to the whole) as the second objective function, etc. Yes (JIS X 0510: 2004 P.45).

  Furthermore, in the present embodiment, the structure of the QR code has been described as an example. Similarly, for other two-dimensional codes, the constituent elements related to the generation of a pattern forming a symbol can be changed to generate and evaluate solution candidates. By repeating the above, the same effect can be obtained.

  In this embodiment, the data code word, error correction level, mask pattern, model number, and padding code word are set as design variables. However, in addition to these five design variables, the remaining code word, the remaining bit, etc. It is good also as a design variable including.

  Furthermore, in this embodiment, the data code word is set as a design variable depending on the position and number of empty segments, the presence / absence of non-empty segment division, etc., but even in the case where confidential information is not included, the final procedure is as described above. A typical two-dimensional code can be determined.

(Other embodiments)
Each means constituting the two-dimensional code generation device and each step of the two-dimensional code generation method in the embodiment of the present invention described above can be realized by operating a program stored in a RAM or ROM of a computer. This program and a computer-readable storage medium storing the program are included in the present invention.

  In addition, the present invention can be implemented as, for example, a system, apparatus, method, program, storage medium, or the like. Specifically, the present invention may be applied to a system including a plurality of devices. The present invention may be applied to an apparatus composed of a single device.

  In the present invention, a software program for realizing the functions of the above-described embodiment (in the embodiment, a program corresponding to the flowcharts shown in FIGS. 8 and 10) may be supplied directly or remotely to the system or apparatus. Including. This includes the case where the system or the computer of the apparatus is also achieved by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. That is, the present invention also includes a computer program for realizing the functional processing of the present invention.

  In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, and the like.

  Examples of the storage medium for supplying the program include a flexible disk, a hard disk, an optical disk, and a magneto-optical disk. Further, there are MO, CD-ROM, CD-R, CD-RW, magnetic tape, nonvolatile memory card, ROM, DVD (DVD-ROM, DVD-R) and the like.

  As another program supply method, there is a method of connecting to an Internet home page using a browser of a client computer. It can also be supplied by downloading the computer program itself of the present invention or a compressed file including an automatic installation function from a homepage to a storage medium such as a hard disk.

  It can also be realized by dividing the program code constituting the program of the present invention into a plurality of files and downloading each file from a different homepage. That is, a WWW server that allows a plurality of users to download a program file for realizing the functional processing of the present invention on a computer is also included in the present invention.

  As another method, the program of the present invention is encrypted, stored in a storage medium such as a CD-ROM, distributed to users, and encrypted from a homepage via the Internet to users who have cleared predetermined conditions. It is also possible to download the key information to be solved and use the key information to execute the encrypted program and install it in the computer.

  Further, the functions of the above-described embodiments are realized by the computer executing the read program. Furthermore, based on the instructions of the program, an OS or the like running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments can be realized by the processing.

  Further, as another method, a program read from a storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, and the function is based on the instructions of the program. A CPU or the like provided in the expansion board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are also realized by the processing.

201 Data Input Unit 202 Solution Candidate Generation Unit 203 Image Input Unit 204 Solution Candidate Evaluation Unit 205 Output Unit 206 Solution Candidate Storage Unit

Claims (7)

A two-dimensional code having a code word in which data is embedded by being divided into a plurality of segments,
A two-dimensional code comprising a segment structure for constituting a module pattern expressing a specific shape. An input process for inputting data as public information, confidential information and an image;
A two-dimensional code in which the data is encoded as a solution candidate is generated using a plurality of constituent elements including the constituent elements of the segment corresponding to the confidential information storing the data as a variable in relation to generation of the cell arrangement pattern Solution candidate generation process;
A solution candidate evaluation step of evaluating whether the solution candidate generated in the solution candidate generation step is similar to the image based on at least one objective function;
In the solution candidate generation step, according to the evaluation in the solution candidate evaluation step, generate a new solution candidate based on the plurality of components,
In the solution candidate evaluation step, a new solution candidate generated in the solution candidate generation step is evaluated.   3. The two-dimensional code generation method according to claim 2, wherein, in the solution candidate evaluation step, the similarity with the image is calculated to evaluate whether or not they are similar.   3. The solution candidate generation step generates a new solution candidate based on the plurality of components and the calculated similarity according to the evaluation in the solution candidate evaluation step. The two-dimensional code generation method described in 1. Input means for inputting data, confidential information and images as public information;
A two-dimensional code in which the data is encoded as a solution candidate is generated using a plurality of constituent elements including the constituent elements of the segment corresponding to the confidential information storing the data as a variable in relation to generation of the cell arrangement pattern Solution candidate generation means;
Solution candidate evaluation means for evaluating whether or not the solution candidate generated by the solution candidate generation means is similar to the image based on at least one objective function;
The solution candidate generation unit generates a new solution candidate based on the plurality of components according to the evaluation by the solution candidate evaluation unit,
The solution candidate evaluation means evaluates a new solution candidate generated by the solution candidate generation means.   A program for causing a computer to execute each step of the two-dimensional code generation method according to any one of claims 2 to 4.   A computer-readable storage medium storing the program according to claim 6.

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