JP5356701B2 - Two-dimensional code and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide display of beautiful two-dimensional codes with homogeneity and a high sense of design, and to restore expressed bit strings in response to various situations. <P>SOLUTION: In a display of cells having a color with a low visibility against a blank area surrounding the two-dimensional code, a gradation of a color component having a gradation close to that of the blank area is set with a contrast with the blank area set, and/or in a display of cells having a color with a high visibility against the blank area surrounding the two-dimensional code, a gradation of a color component having a gradation far from that of the blank area is set with the contrast with the blank area reduced. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention obtains image data by capturing an image with a two-dimensional code displayed on the display of the image display device or output from the image forming device to a sheet-like recording medium or a solid surface by an imaging device. The present invention relates to a two-dimensional code and a program capable of restoring a bit string expressed in the two-dimensional code by analyzing using a computer.

A two-dimensional code is generally composed of a plurality of cells arranged in a lattice and positioning symbols arranged around the cells, and expresses a bit string on a plane. Usually, the bit string is the minimum unit of information handled by the computer, and is composed of a combination of 1 or 0 of each digit in the binary string.
For example, the cell is assumed to be on a white plane, and is composed of two types: a mark cell in which a black data mark is marked and a blank cell in which white is exposed without being marked with a data mark. Thus, a bit pattern is expressed by forming an arrangement pattern by displaying cells. That is, for example, a mark cell is associated with 1 and a blank cell is associated with 0, thereby expressing a bit string of 1 and 0.
With respect to the two-dimensional code displayed in this way, it is possible to restore the bit string by acquiring image data using an optical imaging device and analyzing the image data. For the analysis, a computer is used to determine the position of the cell on the image data, and the display of the cell is determined at that position. Accordingly, the bit string expressed in the two-dimensional code can be restored based on the revealed cell display.

The position of the cell can be calculated with reference to a positioning symbol or a positioning mark that is fixedly displayed at a specific position. For example, a method is known in which the size and inclination of a two-dimensional code in image data is obtained from the distance and angle between two or more detected positioning symbols / positioning marks, and the position of each cell is calculated based on this. (Non-patent Document 1, Patent Document 3).
A method of determining the display of a cell from the value of gradation (or density) at the approximate center position of the cell is known (Non-Patent Document 1). In this method, the gray level of the central pixel of the cell is compared with a threshold value prepared in advance, a cell whose gray level is higher (higher density) than the threshold value is a mark cell, and the gray level is lower (density is lower). Low) cells can be considered blank cells.
A method is known in which the threshold value is calculated based on the gradation of the image by displaying a reference image in a predetermined area (Patent Document 1). When this method is used, the reliability of the threshold value is increased, so that the determination accuracy is improved.

  In recent years, a color two-dimensional code has been proposed as a development of the conventional monochrome two-dimensional code (Patent Document 1). In the color two-dimensional code, by expressing the cell display with a plurality of types of colors, it is possible to display a bit string at a higher density than a monochrome two-dimensional code consisting of only two types of white and black.

In the two-dimensional code, the display density of the bit string can be improved as compared with the conventional bar code. That is, a bit string having a desired capacity can be displayed in a limited display range. Due to this feature, two-dimensional codes have been used in many fields in recent years.
For example, digital information such as character information, image information, audio information, encryption information, and a command code on a computer is displayed on an image display device as a two-dimensional code and used for reading with an imaging device. In addition, the digital information is used for recording on a sheet-like recording medium such as paper or a solid surface such as an electronic component.

As a method for efficiently using a two-dimensional code, a technique for expressing a bit string prepared corresponding to a record number of a database is disclosed (Patent Document 2). In this case, the target digital information is not embedded in the two-dimensional code but is stored and managed on the network via the server in association with the bit string. As a result, the capacity that can be handled is not limited by the display area of the two-dimensional code, and it is possible to target large-capacity information including moving image information and the like in addition to the digital information described above.
In addition, a technique for performing a predetermined conversion on a bit string expressed in a two-dimensional code is disclosed (Patent Document 2). That is, for example, by performing an encryption process, unauthorized reading by a third party can be prevented. Further, by using an error correction code, it is possible to suppress reading errors caused by erroneous determination of cell display.

WO2004 / 097717 JP 2007-026427 A JP 2007-026428 A JIS X0510 Two-dimensional code symbol-QR code (registered trademark)-Basic specifications

In recent years, digital information having a larger capacity than before has been handled due to technological progress such as improvement in computer processing speed and increase in storage medium capacity. In addition, with the advancement of communication technology, a network environment in which digital information can be easily transmitted and received has been established. In particular, in wireless communication using a mobile device, there is a remarkable improvement in communication speed and increase in its penetration rate. Thereby, it has become possible to exchange information in various scenes without being restricted by temporal and geographical conditions.
Due to the background described above, the two-dimensional code is displayed in various scenes and is used by many users for various purposes. For this reason, it has become a symbolic role for digital information as well as a simple information input / output means. Accordingly, there is a demand for a beautiful design that is uniform and has no sense of incongruity for the two-dimensional code. At the same time, it is required to restore the bit strings in high density while corresponding to various situations.
From the above, it is desired to handle digital information existing around us more easily and comfortably.

A two-dimensional code in which each cell is expressed in color can increase the number of bits that can be expressed in a unit area. On the other hand, each cell has a vivid display, so the user has high expectations for design and a beautiful display is required. .
When the display of the cell is a color that is not conspicuous as compared with the color of the background around the two-dimensional code, such as white or yellow, the mark on the cell appears to be missing. For this reason, the uniformity with cells expressed in colors other than those described above is impaired, resulting in a sense of incongruity. This phenomenon is noticeable when the above color display is present in a cell (edge cell) arranged at the boundary with the surrounding area of the two-dimensional code.
In addition, when the cell display is a color that is conspicuous compared to the background color around the two-dimensional code, such as black, the mark on the cell appears to be emphasized. Therefore, even in this case, a sense of incongruity occurs due to the loss of uniformity with other cells.
On the other hand, when the cell display is restricted, there is a problem that the number of bits that can be expressed is reduced. In contrast to this problem, when the display area of the two-dimensional code is increased, the display area is restricted, which is not a preferable method. Further, when the cell density is increased, the cell restoration accuracy is lowered, which is not a preferable method.

  The present invention has been made in view of the above points, and has a beautiful display excellent in design with respect to a two-dimensional code and restores an expressed bit string corresponding to various situations. A two-dimensional code and a program which are made possible are provided. This makes it possible to easily and comfortably handle digital information existing around us.

In the two-dimensional code according to the first aspect of the present invention, for a plurality of cells arranged two-dimensionally, a bit string is expressed by a combination of gradations in a plurality of color components constituting the display of the cells. In the two-dimensional code, the display of the cell expresses a bit string corresponding to a combination of presence / absence of a mark in each color component, and has a mark for expressing the bit string in all color components. and Te cells smell not, the mark does not represent a prior SL bit string is displayed with a contrast to the gradation of the color components between the blank area region and the mark to which the mark is displayed is not displayed, It is characterized by.

In the two-dimensional code according to the second aspect of the present invention, for a plurality of cells arranged two-dimensionally, a bit string is expressed by a combination of gradations in a plurality of color components constituting the display of the cells. In the two-dimensional code, the display of the cell expresses a bit string corresponding to a combination of presence / absence of marks in each color component, and has a mark for expressing the bit string in all color components Te cells odor, marks representing the previous SL bit string is displayed suppressed than other cells contrast of gradation of the color components between the blank area region and the mark to which the mark is displayed is not displayed It is characterized by this.

  The two-dimensional code according to a third aspect of the present invention is characterized in that the display of the cell is expressed by the mark arranged so as to be surrounded by the blank area for each cell.

The two-dimensional code issuance program according to claim 4 according to the present invention is such that a bit string is expressed by a combination of gradations in a plurality of color components constituting a display of a plurality of cells arranged two-dimensionally. relates two-dimensional code, a two-dimensional code issuing program for issuing the two-dimensional code, the mark does not represent a prior SL bit sequence, between the blank area region and the mark to which the mark is displayed is not displayed in that provided a contrast to the tone of the color components, and / or a mark representing the front Symbol bit sequence, between the blank area region and the mark to which the mark is displayed is not displayed It is characterized in that the gradation of the color component is provided with lower contrast than other cells.

  The display of the cell to be set has a color with low visibility / color with high visibility. A color with low visibility refers to a color that is inconspicuous compared with the color of the blank area. On the other hand, a highly visible color refers to a color that stands out in contrast to the color in the blank area.

As a color with low visibility with respect to the blank area, a case where the gradation of all the color components is a combination close to the blank area is assumed. For example, when the blank area is white (for example, the gradation of each color component is 0%), the color is close to white (the gradation of each color component is close to 0%). Further, when the blank area is black (for example, the gradation of each color component is 100%), a color close to black (the gradation of each color component is close to 100%) can be mentioned.
It is also assumed that the combination of gradations differs from the blank area depending on the combination of color components. For example, yellow when the blank area is white, blue or green when the blank area is black, and the like. In addition, a color with a small brightness difference usually has low visibility, for example, a color with a small brightness difference from white when the blank area is white, or a color with a small brightness difference from black when the blank area is black. .

As a color having high visibility with respect to the blank area, a case where the gradation of all the color components is a combination far from the blank area is assumed. For example, when the blank area is white (for example, the gradation of each color component is 0%), the color is close to black (the gradation of each color component is close to 100%). Further, when the blank area is black (for example, the gradation of each color component is 100%), the color is close to white (the gradation of each color component is close to 0%).
Further, depending on the combination of color components, for example, blue and red when the blank area is white, yellow when the blank area is black, and the like can be given. In general, a color with a large lightness difference has high visibility, for example, a color with a large lightness difference from white when the blank area is white, or a color with a large lightness difference from black when the blank area is black. .

  The gradation setting may be performed independently of the represented bit string based on a predetermined rule. Accordingly, it is preferable to adjust and set the gradation of a predetermined color component within a range in which a cell display determination error does not occur when the two-dimensional code is restored.

For example, in the color with low visibility, it is preferable to provide a contrast of 5% to 30% to the gradation with the blank area. More preferably, the contrast with the blank area is set to 5% to 20% from the viewpoint of determination accuracy at the time of restoration.
For example, in the color with high visibility, when the maximum contrast that can be taken with the blank area is 100%, the contrast with the blank area may be set to 70% to 95%. More preferably, the contrast with the blank area is set to 80% to 95% from the viewpoint of determination accuracy during restoration.
In the gradation setting, in the case of a color with low visibility, it is preferable to target a color component having a gradation close to a blank area. In the case of a highly visible color, it is preferable to target a color component having a gradation far from the blank area.

A plurality of color components constituting the display of the cell express colors by combining them. For example, it may be expressed by an additive color mixture of “three primary colors of light” of red, green, and blue. In addition, it is preferable to express by subtractive color mixture using “the three primary colors” of cyan, magenta, and yellow. Further, other color components possessed by the image format or the output device may be used.
The gradation of the color component may be set to, for example, 0% without a mark and 100% with a mark depending on the presence / absence of the mark. Conversely, 100% without a mark and 0% with a mark may be set. The bit string is expressed by assigning mark presence / absence to a plurality of color components.
However, unlike the above, a cell having a low visibility color / a high color tone is set according to the display of the cell. For example, in a color with low visibility, it may be set by adding a gradation to a predetermined color component (for example, gradation 10%). In addition, for example, in a color with high visibility, the gradation of a predetermined color component may be reduced and set (for example, gradation 90%).

  The program that is a component of the present invention is preferably a program that is executed on a computer, that is, software. In addition, dedicated hardware prepared for realizing this may be used, or a combination of these software and hardware may be used.

The computer that executes the program may be a computer that is generally widespread, and may be a computer mounted on an electronic device such as a mobile phone or a PDA, in addition to a computer such as a personal computer, workstation, or mainframe. Further, it may be a computer specially prepared for executing this program.
The computer that executes the program may be a server connected to a network. In this case, it is preferable to execute a predetermined operation in response to a request from the client terminal. The server may be one that is generally popular, and preferably has functions generally expected of the server, such as security and backup.

  According to the two-dimensional code and the program according to the first to fourth aspects of the present invention, the display of each cell has a suitable color, and a display with high homogeneity can be obtained over the entire cell region. As a result, the two-dimensional code has a beautiful display excellent in design and can restore the represented bit string corresponding to various situations.

  Hereinafter, preferred embodiments for realizing the present invention will be described. However, the following description is one form of this invention, and is not limited to this.

<Device configuration>
As shown in FIG. 1, the apparatus for realizing this embodiment includes a server M01, a content registration apparatus M02, and a two-dimensional code acquisition apparatus M03. These devices comprise means for communicating with the network.
As the server M01, the content registration device M02, and the two-dimensional code acquisition device M03, an existing device that is generally used may be used. In this embodiment, a PC (Personal Computer) is used as the content registration apparatus M02. In addition, as the two-dimensional code acquisition device M03, a portable terminal (camera-equipped portable terminal) having an imaging function was used. However, a mobile terminal may be used as the content registration device M02. A PC having an image input function may be used as the two-dimensional code acquisition device M03.
The server M01 can process a plurality of operations simultaneously in response to requests from a plurality of users. In this embodiment, the server M01 performs a plurality of roles (two-dimensional code issuance, restoration, database management, etc.) by a single server device. However, a plurality of server devices may be prepared and a plurality of roles may be distributed. That is, the server of the present invention includes a server group composed of two or more server devices.

<Assumed usage pattern>
In this embodiment, using a two-dimensional code, a plurality of users share content composed of electronic data on a network. For example, the user A registers the content in the server and issues a two-dimensional code at the same time, and then another user B restores the two-dimensional code to identify and acquire the content.
The users A and B are not limited to the above case. For example, in a certain situation, a plurality of users B acquire the same content registered in the server. In other situations, the users A and B are the same person, and the content registered by themselves is acquired later.

<Target content>
The content in this embodiment targets electronic data in a non-limiting format such as character information, image information (still images and moving images), audio information, and the like.
The character information refers to text data described in an arbitrary format such as URL (Uniform Resource Locator), personal data (address / name / phone number), memo, mail document, and the like. The text data is represented by a character code such as EUC code, ShiftJis code, Unicode, and the like.
The image information indicates, for example, still image data in a data format such as jpeg or bitmap. In addition, for example, it indicates moving image data in a data format such as mpeg, wmv, and avi. For example, the audio information indicates music data in a data format such as mp3 or wav.
As an example other than the above, electronic data created by a specific application is targeted. For example, it refers to data created by word processing software, data created by spreadsheet software, data created by schedule management software, and the like. Further, authentication data such as an ID and a password, encrypted data that is an encrypted bit string, and an instruction code (executable program) on a computer are targeted.

<Action on content>
In this embodiment, the user A selects an operation at the time of restoring the two-dimensional code when registering the content. The selected operation is recorded in the database of the server M01 as the operation type. The operation type is referred to when the two-dimensional code is restored, and is executed via a program on the server M01.
Table 1 shows an example of a plurality of operation types prepared in this embodiment and numbers (operation type numbers) assigned to the respective operation types. As the operation type of this embodiment, an operation assumed for each type of content is prepared in advance. At that time, a plurality of operation types are provided for the same type of content.
Hereinafter, examples of a plurality of operations prepared in this embodiment will be described. The operation types described individually may be executed in combination.

<First Example of Operation: Send to Mobile Terminal>
In the first example of the operation according to this embodiment, the server M01 transmits content to the mobile terminal that is the two-dimensional code acquisition device M03 (A000).
For example, when the content is text information, the user B displays the content on the display of the portable terminal and reads it (A001). Also, the URL described is designated and accessed from the portable terminal (A002).
If the content is image information (still image), the image is displayed on the display of the portable terminal (A011). In the case of a moving image, the moving image data is reproduced (A021). In the case of audio information, the music data is reproduced on the portable terminal (A031).

<Second Example of Operation: Processing in Server>
In the second example of the operation according to this embodiment, the server M01 registers content in the server M01.
In this embodiment, the user B has a home page in the server M01 and registers content on the home page. Thereafter, user B accesses and uses the home page.
If the content is text information, for example, the described URL is registered in the bookmark list on the home page (A102). The described personal information (address, name, phone number) is registered in the address book on the homepage (A103).
If the content is image information, the image (still image) is registered in the home page album (A111). In the case of voice information, the music data is registered in the music list on the home page (A131).

<Third example of operation: Send to other server>
In the third example of the operation of this embodiment, the server M01 transmits content to the other server M11.
In the third example, the home page of the user B is managed by the server M11. The server M11 is assumed to be managed by a management entity (for example, a general network service provider) different from the server M01.
The server M01 transmits the operation type to the server M11 simultaneously with the content. The server M11 refers to the operation type and processes the same operation as in the second example. That is, bookmark registration (A202) on the home page on the server M11, address book registration (A203), album registration (A211), music registration (A231), and the like are performed.

<Database>
The database is configured in a table format having rows as records and columns as fields, and records information by providing a plurality of fields in each record. The database of this embodiment is described in SQL, which is a general-purpose language. In addition, SQLight, which is a popular application, was used. However, MySQL, PostgreSQL, Oracle, etc. may be used as the application.
Table 2 shows an example of the database used in this embodiment. The database in this embodiment has fields for recording record numbers, header numbers, operation types, storage addresses, and statuses.

In the record number field, the record number (D00) is recorded. In this embodiment, a binary number bit string is recorded. However, it may be recorded in decimal numbers.
In the header number field, the header number (D10) is recorded.
The action type field records the action type for the content after the two-dimensional code is restored (Table 1).
The storage address field records the storage address of the content. The storage address is a storage area in the server M01 or a storage area in another server accessible from the server M01.
The status field records the issue / stop status of the two-dimensional code. As a result, in this embodiment, status = “1” can be restored, and status = “0” cannot. Status = “1” (restorable) was recorded when a two-dimensional code was issued and the program was not stopped. When the two-dimensional code has not been issued and when it has stopped after being issued, the status is set to “0” (restoration is impossible). The stop after the two-dimensional code issuance is performed based on restrictions on use, such as an expiration date.
The database may include fields other than those described above. Thereby, for example, date and time information such as the registration date and the expiration date of the content is recorded. Further, for example, log information may be recorded. Furthermore, for example, the storage address of a file / folder related to the content may be recorded.

<Display format of two-dimensional code>
An overall image of the two-dimensional code 101 used in this embodiment is shown in FIG. In this embodiment, the cells are arranged in a square lattice pattern on the display surface, and an 8 × 8 cell arrangement is adopted. However, the number of cells is not limited to 8 × 8 cells, and may be 12 × 12 cells, for example.
The arrangement of the positioning mark 020 and the reference mark 030 in the two-dimensional code 101 (FIG. 2) is shown in FIG. As shown in FIG. 3, the positioning mark 020 and the reference mark 030 are always displayed in the same color at predetermined cell positions. On the other hand, the data mark 010 varies and is displayed for each generated two-dimensional code. That is, a color data mark corresponding to a bit string is displayed in each cell (data cell) indicated by a dotted frame.
However, the cell arrangement shape and the mark shape are not limited to the above. For example, the cell arrangement may be a rectangular shape having different numbers of cells in the vertical and horizontal directions. For example, the cell arrangement may be a hexagonal lattice. The mark shape may be circular.

<Data mark>
A part of the two-dimensional code in a single color component is enlarged and displayed in FIG. As shown in FIG. 4, each color component cell is represented by either a cell having a mark (mark cell 001) or a cell having no mark (blank cell 002). A color mark is formed by combining the presence or absence of a mark for each color component.
As shown in FIG. 5, each of the cells 001 and 002 includes an area where a mark is displayed (mark area 003) and an area where no mark is displayed (blank area 004). The data mark of each cell is displayed with a space around it as in this embodiment, so that it is separated from the data mark of the adjacent cell.

As for the display of the cell by the data mark, the entire display was scanned while evaluating the cell, and a desired display was selected. The cell evaluation was conducted on a set of some cells.
In this embodiment, as shown in FIG. 6, a combination of color displays is acquired from two cells (horizontal direction and vertical direction) arranged in succession, and scoring is performed. Table 3 shows the scoring (2 cells) of this embodiment. The colors (W, C, M, Y, R, G, B, K) shown in the rows and columns of Table 3 correspond to the color display in the two cells (10P, 010Q) in FIG.
In this embodiment, at the same time, a color display is obtained from each cell located on the top, bottom, left, and right sides of the two-dimensional code, and scoring is performed. Table 4 shows the scoring (1 cell) used in this embodiment.
In this embodiment, the verification of the entire two-dimensional code is performed by summing up the points acquired from two cells in the horizontal / vertical direction (FIG. 6) and one cell on the side, and regarding a display with a small sum as a suitable display. did.
By using the scoring in Table 3, the cell display was prevented from becoming black. In particular, it was avoided that both two consecutive cells became black. Similarly, it was avoided that the cell display became white. In particular, it was avoided that two consecutive cells were white. Moreover, it was avoided that two continuous cells other than black and white became the same color.
By using the scoring in Table 4, the display of cells on the side was prevented from becoming white. Similarly, the display of the cell on the side was prevented from becoming black.

<Positioning mark>
The positioning mark 020 is fixed and displayed in a specific cell as a reference for the position of the two-dimensional code. It is preferable that a plurality of positioning marks 020 exist. In this embodiment, as shown in FIG. 3, the positioning marks 020 are arranged at the four corners of a quadrangular code area. The image pattern of the positioning mark 020 has the same shape and size as the data mark.
In this embodiment, the positioning mark 020 is displayed in black, and the surrounding blank area is displayed in white. That is, the positioning mark is displayed with a contrast between the surrounding blank areas for all color components of the output device.

<Reference mark>
The reference mark 030 is displayed in a predetermined color in a specific cell in order to acquire reference information for determining cell display. In this embodiment, as shown in FIG. 3, reference marks of white 030W, cyan 030C, magenta 030M, yellow 030Y, red 030R, green 030G, and blue 030B are displayed near the four corners of the code area. At this time, the reference mark 030 is an image pattern having the same shape and the same size as the data mark, like the positioning mark.
In this embodiment, the black reference mark is not particularly displayed. However, the positioning mark 020 of this embodiment has the same shape and size as the data mark, and the positioning mark 020 also serves as a reference mark. When displaying a black reference mark, it is preferable to use an image pattern having the same shape, size, and color as the positioning mark.

<Makeup mark>
The display of the makeup mark is determined according to the presence / absence of marks of other color components in the corresponding cell. In addition, the display was determined according to the display combination of the surrounding cells. The display was determined by evaluating each with or without a makeup mark, and selecting a suitable one.
In this embodiment, the combination of the display of the cell having the decoration mark and the cell adjacent to the cell is scored using the table shown in Table 3. The scoring was performed on adjacent cells in the upper, lower, left, and right directions, and the sum of the scores was considered to be the better. As shown in FIG. 6, the adjacent cells are continuously arranged in the horizontal direction or the vertical direction, and a combination of color displays is acquired and evaluated.
However, the presence / absence of a makeup mark can be selected without evaluating surrounding cells. For example, when there is another color component in the corresponding cell, “no mark” may be selected, and when no color component exists, “with mark” may be selected.
In this embodiment, as shown in FIG. 7, a makeup mark is assigned to a part of the data cell. Thereby, it mixed with the data mark and arrange | positioned avoiding the adjoining of makeup marks. At that time, the makeup mark was assigned only a single color component in the same cell. Further, the plurality of color components are assigned almost uniformly. In this embodiment, a total of 18 makeup marks are assigned to each of the cyan component 040C, the magenta component 040M, and the yellow component 040Y. These color components were dispersed in the plane.

<Tone correction for specific colors>
The gradation displayed on the mark displayed in the cell is corrected for a specific color. In the correction, the gradation is determined according to the color display of the corresponding cell. That is, it was determined from the presence or absence of marks of other color components in the same cell. Table 5 shows the gradation for each color component used in this embodiment for each color.
In this embodiment, correction is applied to colors (white, yellow, etc.) that are not conspicuous as compared with the surrounding blank area (white), and the gradation is changed by a certain ratio in the higher direction. As shown in Table 5, when the cell display was white, the gradation of each color component of the cell was corrected by increasing it by 10%. That is, the gradation (0, 0, 0) of the (cyan, magenta, yellow) component in white is set to (0.1, 0.1, 0.1). Similarly, when the cell display is yellow, the gradation of color components other than yellow is increased by 10%, and the gradation of yellow (0, 0, 1) is changed to (0.1, 0.1, 1). ).
It is also effective to correct the color (black, etc.) that is conspicuous as compared with the display of other cells and change the gradation in a lower direction. For example, when the cell display is black, the gradation of each color component may be corrected by lowering it by about 5% to 20%. For example, the black gradation (1, 1, 1) may be reduced by 10% for each color component to (0.9, 0.9, 0.9).

<2D code issuance / restoration process>
The process for realizing this embodiment includes a two-dimensional code issuance process for processing issuance of a two-dimensional code and a two-dimensional code restoration process for processing restoration of a two-dimensional code.
In the two-dimensional code issuance process, content is stored in the storage area of the server M01 in response to a request from the user A who operates the content registration apparatus M02. At that time, the server M01 issues a two-dimensional code 100 associated with the storage address of the content, and manages the association using the database (Table 2). After receiving the two-dimensional code 100, the user A uses it according to the purpose.
In the two-dimensional code restoration process, the user B acquires the image data of the two-dimensional code 100 using the two-dimensional code acquisition device M03 and transmits it to the server M01. After analyzing the received image data, the server M01 refers to the database and identifies the content associated with the two-dimensional code 100. The identified content is used by the user B.

<2D code issuance process>
A two-dimensional code issuing process 200 in this embodiment is shown in FIG. The two-dimensional code issuance process 200 of this embodiment includes a data input unit 210, a two-dimensional code generation unit 220, and a two-dimensional code output unit 230.

<Data input section>
The data input unit 211 acquires a bit string and inputs it to the two-dimensional code generation unit 220. The data input unit 210 according to this embodiment includes data input means 211 (FIG. 8). The data input unit 211 is realized by executing a program prepared in advance in the server M01. The bit string handled in this embodiment is a set of bits (bit string) which is the minimum unit of information handled by the computer.
The data input means 211 of this embodiment acquires a database record number D00 as the bit string. The record number D00 specifies a database record.
In this embodiment, the record number D00 is a bit string generated in ascending order, and assigned to a database for recording. Thereafter, when a two-dimensional code is issued, an unused record number D00 is selected in order. The issued two-dimensional code is managed using a database by being associated with the record number D00.

<2D code generator>
The two-dimensional code generation unit 220 creates two-dimensional code image data based on the bit string transferred from the data input unit 210. Thereafter, the image data is transferred to the two-dimensional code output unit 230.
As shown in FIG. 8, the two-dimensional code generation unit 220 of this embodiment includes a data conversion unit 221, an encoding unit 222, an image creation unit 223, and an image conversion unit 224. These means are realized by executing a program prepared in advance in the server M01.
Hereinafter, the data conversion unit 221, the encoding unit 222, the image creation unit 223, and the image conversion unit 224 will be described.

<Data conversion means>
The data conversion unit 221 acquires code data D20 to be embedded in the two-dimensional code based on the database record number D00. FIG. 9 shows a series of flows for converting the record number D00 and obtaining the code data D20. The flow will be described below.

[Redundant bit assignment C00]
The record number D00 (decimal) is converted into a binary bit string, and then a redundant bit is added via the process C00 to generate data D01. In this embodiment, the redundant bit is assigned to a plurality of cell display candidates. The bit string selected as the cell display is recorded in the database 120. The redundant bits to be added have a certain number of digits. In this embodiment, the upper 10 bits of the data D01 are assigned to the redundant bits.
[Encryption C01]
Data D01 is subjected to an encryption process C01 to generate data D02. In this embodiment, DES (Data Encryption Standard), triple DES, AES (Advanced Encryption Standard), or the like, which is a standard encryption method, may be used as the encryption technique.
[Error correction code C02]
The data D02 is subjected to error correction coding processing C02 to generate data D03. In this embodiment, as the error correction code, a BCH (Bose-Chudhuri-Hocquenhem) code, an extended BCH code, a Reed-Solomon code, or the like may be used. The error correction code is prepared in a predetermined combination (n, k, d) with respect to the total number of code bits n, the number of information bits k, and the minimum Hamming distance d.
[Bit position conversion C03]
The data D03 is subjected to bit position conversion processing C03 to generate data D04. In this process, the bit positions of the data D03 are exchanged. In the bit position conversion of this embodiment, a plurality of conversion rules are prepared and stored in the server M01 in association with the header number D10. The bit position conversion rule was randomized using a predetermined randomization algorithm.

[Header number D10]
The header number D10 specifies the conversion rule used in the bit position conversion process C03. However, in this embodiment, some bits of the header number D10 are assigned to the identification of the conversion rule. The remaining bits were assigned to version number management and fixed to ensure future scalability.
[Encryption C11]
The header number D10 is subjected to encryption processing C11, and data D11 is generated. In this embodiment, as the encryption process C11, a common key encryption process, which is a known technique, is performed.
[Error correction code C12]
The data D11 is subjected to error correction coding processing C12 to generate data D12.

[Data Join C20]
Data D04 and data D12 obtained through the above process are combined to obtain code data D20. In this embodiment, each bit position is randomly assigned in the combination of the two bit strings. However, the combination rule is fixed and stored in the server M01.

<Encoding means>
The encoding unit 222 determines the color display of each cell based on the code data D20 obtained by the data conversion unit 221. A conceptual diagram of cell display determination in this embodiment is shown in FIG.
In FIG. 10, each bit of the code data D20 is distributed to each color component of cyan, magenta, and yellow according to a predetermined rule. Also, bits are assigned to cells for each color component, and the presence / absence of a mark in each cell is determined. At this time, “1” of each bit is associated with “marked” and “0” is associated with “without mark”.
After that, the presence / absence of marks (110C, 110M, 110Y) of each color component was overlaid to determine the color display (110) of each cell. That is, by combining the color components of cyan C, magenta M, and yellow Y, in addition to cyan C, magenta M, and yellow Y, red R (= M + Y), green G (= C + Y), blue B (= C + M), And black K (= C + M + Y) was determined. Moreover, white W which does not have any color component was determined.

The encoding means 222 extracted a plurality of candidates for the cell display. Moreover, the suitable thing was selected from several extracted candidates using the predetermined selection rule. At that time, rules not disclosed to the public were used for the selection. The bit string specifying the selected display was recorded in a predetermined bit of the data D01 and also recorded in the corresponding record of the database 120 (FIG. 8).
In addition, the encoding means 222 determines the display of the makeup mark in a part of the predetermined data cell. That is, the presence / absence of a makeup mark is determined in accordance with other color components in the corresponding cell and / or display of surrounding cells.

The two-dimensional code represents a bit string (code data D20) by displaying cells. At this time, the number of bits of the code data D20 is determined as (number of bits of code data) = (total number of cells−number of positioning cells−number of reference cells) × (number of color components) − (number of makeup marks). It was.
In this embodiment, out of the total 64 cells (= 8 × 8 cells) of the two-dimensional code, 4 cells (4 locations) are used for the positioning mark 020 and 7 cells (W, C, M, Y, R, G, B) were assigned, and 53 cells were assigned to the data cells.
The code data D20 can be assigned up to 159 bits (= 53 cells × 3 color components) by combining the three color components. However, in this embodiment, some bits (18 bits) are assigned to the makeup mark, and 141 bits (= 159 bits−18 bits) are assigned to the code data D20.

<Image forming means>
The image forming unit 223 creates image data including pixels of a two-dimensional array (Row, Column) based on the color display of each cell obtained by the encoding unit 222. In this embodiment, image data of 50 × 50 pixels is created.
Each pixel in the image data has a color component value 0 to 1 of (cyan C, magenta M, yellow Y), and a color is expressed by a combination of the color components. For example, in each pixel, cyan is represented as (1, 0, 0), red is represented as (0, 1, 1), and black is represented as (1, 1, 1).
As an example of image data relating to a single color component (cyan C) of this embodiment, a mark cell 001C is displayed in FIG. As shown in FIG. 11, the mark cell 001C of this embodiment is composed of 5 × 5 pixels, the central 3 × 3 pixel is a mark region 003C, and the surrounding pixel region is a blank region 004C. Each pixel 006 is assigned “1” to the mark area and “0” to the blank area.

In the image forming unit 223, the gradation of each color component in the mark area 003 is corrected for a cell having a specific color. In the present embodiment, correction is performed for white and yellow cells. At that time, the target cell was detected by verifying the combination of the presence or absence of each color component. In this embodiment, the gradation of each pixel is set for the detected cell using the predetermined rule shown in Table 5.
In this embodiment, the value of each color component is (0.1, 0.1, 0.1) in the mark area of the white cell (0, 0, 0). In the yellow cell (0, 0, 1), the value of each color component is (0.1, 0.1, 1).
FIG. 12 shows an example of a single color component (cyan C) that does not include a mark in white and yellow cells. As shown in FIG. 12, in the white and yellow cells (blank cell 002C), the gradation of the mark area is corrected and a gradation of 0.1 is assigned.

<Image conversion means>
The image conversion unit 224 converts the image data obtained by the image forming unit 223 into a generally popular image format. In this embodiment, it is converted into the GIF format. However, the image format may be a PPM (Portable Pix Map) format, a bitmap format, a Jpeg format, a GIF format, or the like.
In the above image format, generally, each color component has multi-level gradation values, and the color is expressed by the color components of (red R, green G, blue B). In this embodiment, the image format is converted into RGB 24-bit color (RGB gradation representation of 256 colors).

The value of each pixel is, for example, cyan (1, 0, 0) to (0, 255, 255), red (0, 1, 1) to (0, 0, 255), black (1, 1, 0). 1) was converted to (0, 0, 0), respectively. Further, white (0.1, 0.1, 0.1) after color adjustment is (229, 229, 229), and yellow (0.1, 0.1, 1) is (229, 229, 0). ).
In the example of FIG. 11 relating to a single color component (cyan C), the value of the CMY component in each pixel is converted to the gradation of the RGB component. That is, the mark area is converted from the cyan component “1” to the red component “0”, and the blank area is converted from the cyan component “0” to the red component “255”. In the example of FIG. 12 regarding color correction (cyan component) of the blank cell, the mark area is converted from the cyan component “0.1” to the red component “229”.

<2D code output unit>
The two-dimensional code output unit 230 transmits the image data of the two-dimensional code created by the two-dimensional code generation unit 220 to the content registration device M02 and outputs it.
As shown in FIG. 8, the two-dimensional code output unit 230 according to this embodiment includes a two-dimensional code output unit 231. The two-dimensional code output unit 231 is realized by executing a program prepared in advance in the server M01. In addition, for the communication of the two-dimensional code output means 231, existing communication technology is used.

In this embodiment, the user A displays the two-dimensional code received by the content registration device M02 in a form that is not particularly limited.
In this embodiment, it is assumed that the two-dimensional code is displayed on an image display device connected to a computer. In addition, it is assumed that the image is output and displayed on the sheet-like recording medium or solid surface by the image forming apparatus.

In general, an image display device forms an image by expressing pixels by light emission of a light emitter. As the image display apparatus of this embodiment, a liquid crystal display (for example, 160 dpi, RGB 32-bit color) is suitable. Further, a CRT (Cathode Ray Tube) type display, a plasma display, or the like may be used.
For example, a two-dimensional code is displayed on the WEB page, published on the net, and displayed on the display of the accessed PC. In addition, for example, a two-dimensional code display area is provided in a television broadcast video, so that the video is displayed on a television display.

An image forming apparatus usually outputs ink or toner to a recording medium to express pixels and forms an image. As the image forming apparatus of this embodiment, an output device (for example, 600 dpi) using an inkjet method is suitable. Further, an electrophotographic output machine, a printing machine, or the like may be used.
For example, the two-dimensional code is output to a sheet using an ink jet printer provided in the PC. In addition, for example, it is output to a printed matter such as a flyer, a business card, or wrapping paper using a printing machine. Furthermore, for example, it may be output on the surface of the manufactured solid product.

<2D code issuance flow>
An example of operations in the server M01 and the content registration device M02 and communication performed between the devices in the two-dimensional code issuing process of this embodiment will be described below with reference to FIG.

S101: The server M01 waits for access from the content registration device M02.
S102: The content registration apparatus M02 accesses the URL (Web page) of the server M01 according to an instruction from the user A.
S103: The server M01 returns an input screen in response to the access from the content registration apparatus M02.
S104: User A specifies content and selects an action type for the content on the input screen. The content registration device M02 transmits the content and operation type to the server M01.
S105: The server M01 stores the received content in the storage area. Also, a database record is allocated, and the storage address of the content (for example, “file: // storage / 00... 01”) and the selected operation type are stored in a predetermined field.
S106: The server M01 converts the record number D00 of the record into code data D20, and generates image data of a two-dimensional code representing the code data. In addition, the image data is transmitted to the content registration device M02. The operation by the server M01 is realized by the two-dimensional code issuing process.
S107: After the content registration apparatus M02 receives the image data of the two-dimensional code, the user A displays and uses the two-dimensional code.

  The communication protocol of the server M01 and the content registration device M02 is not particularly limited. This embodiment is realized by HTTP, using an http daemon (http service) for S101 and a GET command and its response for S102 and S103, respectively. A POST command and its response are used for S104 and S106. The input screen returned in S103 is described in HTML (and JAVA (registered trademark) script, etc.). S105 and S106 are realized by a CGI program or a servlet on the server side.

<2D code restoration process>
FIG. 14 shows a two-dimensional code restoration process 300 in this embodiment. The two-dimensional code restoration process 300 of this embodiment includes a two-dimensional code input unit 310, a two-dimensional code decoding unit 320, and a data output unit 330.

<2D code input section>
The two-dimensional code input unit 310 receives and acquires image data of the two-dimensional code from the two-dimensional code acquisition device M03, and passes it to the two-dimensional code decoding unit 320.
As shown in FIG. 14, the two-dimensional code input unit 310 according to this embodiment includes a two-dimensional code input unit 311. The two-dimensional code input unit 311 is realized by executing a program prepared in advance in the server M01.
The image data of this embodiment is acquired by the user B using the two-dimensional code acquisition device M03, and then transmitted to the server M01 via the network. The server M01 stores the received image data in a memory in the server M01. Existing communication technology was used for communication between the server M01 and the two-dimensional code acquisition apparatus M03.

<2D code acquisition device>
The two-dimensional code acquisition apparatus M03 of this embodiment acquires a digital image using a CCD (Charged Coupled Device). As the two-dimensional code acquisition device M03, a portable terminal having a camera function (for example, 240 × 320 pixels, RGB 24-bit color) is suitable. The two-dimensional code acquisition device M03 may be a flat bed scanner (for example, 600 dpi, RGB 24-bit color).
When the image is captured by the camera of the portable terminal, the image data of the two-dimensional code is preferably transmitted using the communication unit of the portable terminal. In addition, when scanned by a flood bed scanner, it may be transmitted using a communication means of a PC connected to the flat bed scanner.

<Acquired image data>
In the image data handled in this embodiment, each pixel is composed of a plurality of color components and has multiple levels of gradation, as in the two-dimensional code issuing process 200. Thereby, for example, a color is expressed by an additive color mixture of (red R, green G, blue B). In this embodiment, image formats such as JPEG format, GIF format, PPM format, and bitmap format are not limited.
An example of image data (256 gradations) relating to a single color component (red R) is displayed in FIG. In FIG. 15, the mark cell 001R is displayed.
As shown in FIG. 15, the mark cell 001R in the image data has a variation from the image (FIG. 11) at the time of generating the two-dimensional code due to the influence of noise at the time of input / output. Thus, each pixel 007 has gradations of mark area: about 28 to 128 and blank area: about 102 to 204.

<Two-dimensional code decoding unit>
The two-dimensional code decoding unit 320 decodes the two-dimensional code in the image data acquired by the two-dimensional code input unit 310. Thereafter, the bit string obtained by decoding is transferred to the data output unit 330.
As shown in FIG. 14, the two-dimensional code decoding unit 320 of this embodiment includes an image conversion unit 321, a positioning unit 322, a cell determination unit 323, a decoding unit 324, and a data conversion / verification unit 325. Each means is realized by executing a program prepared in advance in the server M01.
Hereinafter, the image conversion unit 321, the positioning unit 322, the cell determination unit 323, the decoding unit 324, and the data conversion / verification unit 325 will be described.

<Image conversion means>
The image conversion unit 321 converts the image data input from the two-dimensional code input unit 310 into an image suitable for analysis by the positioning unit 322 and the cell determination unit 323. By this conversion, the positioning image data used by the positioning unit 322 and the cell determination image data used by the cell determination unit 323 are acquired. The obtained image data was stored in the memory area of the server M01.

The cell determination image data is represented by a value of 0 to 1 of the CMY component in each pixel. For example, when the image data before conversion is in RGB 24-bit color representation, the 256 gradations of each color component (red R, green G, blue B) are changed to values of 0 to 1 of (cyan C, magenta M, yellow Y). Converted.
The conversion was performed using the mathematical formula represented by Equation 1. Equation 1 means the conversion of the value of each color component in the pixel (Row, Column).
In the example of FIG. 15 relating to a single color component (red R), the gradation of the RGB component in each pixel is converted into the value of the CMY component, and the mark area is about 0.5 to 0.9, and the blank area is 0. About 2 to 0.6.

For the positioning image data, the cell determination image data was further processed. Thereby, in each pixel, the maximum value is selected from a plurality of color components, and one value is held. For example, each pixel (cyan C, magenta M, yellow Y) is converted into a single maximum value D after conversion.
The conversion was performed using the mathematical formula expressed in Equation 2. In Equation 2, Max (x, y, z) is a function that selects the maximum value from three values (x, y, z).

<Positioning means>
The positioning unit 322 detects a positioning mark in the positioning image data input from the image conversion unit 321 and specifies the position of the two-dimensional code.
As shown in FIG. 16, the positioning means 322 of this embodiment includes steps of code area extraction P101, image information acquisition P102, code area scanning P103, and positioning mark selection P104. As a means for realizing these steps, an execution program is prepared in the server M01.
Hereinafter, each step of the positioning means 322 will be described.

<Code area extraction P101>
In the step of code area extraction P101, an area including the entire two-dimensional code is extracted from the image data. At that time, processing was performed on the positioning image data obtained by the image conversion means 321. The code area extraction P101 of the present embodiment was performed by the following method.

The code area has a contrast between the mark on the cell arranged in a lattice and the blank area. On the other hand, in the blank area existing around the code area, the contrast is assumed to be low. Thereby, an area composed of a code area having a high contrast between the mark area / blank area and a low blank area is extracted.
In this embodiment, Expression 3 is used for determining the code area.
In Equation 3, Vc and Vs mean the size of the contrast of the mark area / blank area in the code area and the surrounding blank area, respectively. From Equation 3, a region with a large index Jc is regarded as a desired code region.
P ₁ in Equation 3 is a positioning parameter and is managed by the process control means 326.
Vc and Vs were calculated by acquiring a plurality of gradations from an area assumed as a cell area, as shown in FIG. 17 (enlarged view). As a result, the gradation is acquired from the pixels in the mark area 031 and the blank area 032 (intermediate between marks). D _max and D _min represent the maximum value and the minimum value of the gradation acquired from the cell region 030. The function F _mc () means an average for the code area cells (64 cells in total). Similarly, the function F _ms () means an average with respect to cells in the blank area assumed in the surrounding 1 cell width (36 cells in total).

  For the code area, the image data was scanned while calculating the index Jc of Equation 3, and the area having the largest Jc was extracted. At that time, the assumed size of the cell in FIG. 17 was reduced / enlarged to correspond to the display size of the two-dimensional code in the image data. The extracted code area was used for processing in other steps by specifying pixel positions at four corners (upper left, upper right, lower left, lower right).

<Image information acquisition P102>
In the step of obtaining image information P102, image information is obtained from the area extracted in the step of extracting code area P101. At that time, the processing of the image information acquisition P102 was performed on the positioning image data obtained by the image conversion means 321. Image information acquisition P102 in this embodiment was performed by the following method.

The image information of this embodiment is calculated based on the distribution obtained from the gradation distribution for the code area. An example of the gradation distribution in this embodiment is shown in FIG. In FIG. 18, the horizontal axis indicates the gradation, and the vertical axis indicates the frequency of each gradation. In this embodiment, the gradation step is 0.02, and the frequency of gradation 0.5 is included in the range of 0.50 to 0.52, for example.
As shown in FIG. 18, normally, there are two peaks corresponding to the mark area and the blank area in the gradation distribution. In the image information of this embodiment, the gradation of each peak is obtained, and the mark area index Mm and the blank area index Mv are determined.

<Code area scan P103>
In the step of code area scanning P103, the area extracted in the step of code area extraction P101 is scanned to detect the image pattern of the positioning mark. At that time, the processing of the code area scan P103 was performed on the positioning image data obtained by the image conversion means 321. The code area scan P103 of this embodiment was performed by the following method.

As shown in FIG. 19, the code area scan P103 scans image data while collating using the collation pattern 008. At that time, the collated image is determined, and the position of the representative pixel is stored if it matches. In this embodiment, the upper left pixel of the assumed mark area is selected as the representative pixel. Thereby, the image pattern in the image data is detected. These series of processes were performed according to the procedure shown in the flowchart of FIG.
The collation pattern 008 is composed of a mark area and a surrounding blank area. As a collation pattern 008 of this embodiment, a pattern of 5 × 5 pixels as a whole was used assuming a blank area of 1 pixel around a 3 × 3 pixel mark area (FIG. 19).

Judgment of the collated image was performed by calculating the average of gradations (D _m and D _v ) from each of the mark area and the blank area, and substituting these into the judgment formula (Equation 4). That is, when the determination formula (Equation 4) is satisfied, it is considered that the image matches the desired image pattern (FIG. 21).
For calculating the average D, a known calculation formula D = Σdi / n was used. However, n means the number of pixels, i means the pixel number, di means the gradation of the pixel i, and Σ means the sum of the pixels in each region.
Mm and Mv are variables corresponding to the image data, and the image information (Mm and Mv) obtained in the step of image information acquisition P102 is used.
Sm and Sv are variables representing the permissible level. In this embodiment, “Sm = Sv = Mm−Mv” is set using Mm and Mv.
P ₂ in the nest 4 is a positioning parameter and is managed by the process control means 326.

<Positioning mark selection P104>
In the positioning mark selection P104 step, a positioning mark is selected from the marks detected in the code area scanning P103 step. Thereby, the specified position is acquired as position data. In this embodiment, the positioning mark selection P104 is performed by the following method.

As shown in FIG. 3, the positioning marks 020 of this embodiment are arranged at the four corners of a quadrangular code area. The positioning mark selection P104 selects the arrangement of the four corners from the set of detection positions including the positioning marks acquired in the code area scanning P103 step.
In the selection of the four corners, as shown in FIG. 22, straight lines (L1 to L4) having an inclination “−1” (135 degrees from the Column axis) and an inclination “1” (45 degrees from the Column axis) passing through the detection position. ) And the arrangement with the minimum / maximum row axis intercept was selected from the set of detection positions.
In FIG. 22, the upper left position 021 from the straight line L1 where “(Row coordinates) + (Column coordinates)” is the smallest, and the upper right position 022 from the straight line L2 where “(Row coordinates) − (Column coordinates)” is the smallest, The lower left position 023 is selected from the straight line L3 where “(Row coordinates) − (Column coordinates)” is maximum, and the lower right position 024 is selected from the straight line L4 where “(Row coordinates) + (Column coordinates)” is maximum. .

  The position data of this embodiment is composed of pixel positions of the selected positioning marks at the four corners. That is, in FIG. 22, the upper left position 021 (Rtl, Ctl), the upper right position 022 (Rtr, Ctr), the lower left position 023 (Rbl, Cbl), and the lower right position 024 (Rbr, Cbr) are used as position data.

<Cell determination means>
The cell determination unit 323 uses the position data acquired by the positioning unit 322 in the cell determination image data input from the image conversion unit 321 to determine and specify the display of each cell.
As shown in FIG. 23, the cell determination unit 323 according to the present embodiment includes cell area calculation P201, cell area scanning P202, reference information acquisition / verification P203, and cell display determination P204. As a means for realizing these steps, an execution program is prepared in the server M01.

<Cell area calculation P201>
In the cell area calculation P201 step, each cell area is calculated using the position data acquired by the positioning means 322. The cell area calculation P201 of this embodiment was performed by the following method.

  For the cells arranged in a lattice pattern, first, the line segment connecting the positioning marks at the four corners was equally divided by the number of cells, and the cell region arranged on the side connecting the four corners was calculated. Next, a line segment connecting the cells on opposite sides was calculated in the Row direction and the Column direction, and the cell region arranged inside the lattice was calculated. At this time, the cell region is designated by using the upper left position in the cell region as a representative pixel. Rounded to the nearest whole number.

<Cell Area Scan P202>
In the step of cell area scanning P202, the cell gradation is obtained for each color component by scanning each cell area in the image data. At that time, as the cell region, the region acquired in the step of cell region calculation P201 was used. The cell area scan P202 of this embodiment was performed by the following method.

The cell area scan P202 of the present embodiment was scanned while collating using the collation pattern 008, similarly to the code area scan P103 step in the positioning means 321 (FIG. 19). Thereby, the mark position of each cell was detected. In addition, an index (cell index) for determining the presence / absence of a cell mark at the detected mark position was acquired.
In this embodiment, the cell index is acquired for each color component. That is, a cell index of (cyan C, magenta M, yellow Y) was acquired. At that time, the mark position was detected using Equation 5, and cell indices (Jm _c , Jm _m , Jm _y ) were obtained. The obtained cell index (Jm _c , Jm _m , Jm _y ) was stored in the memory area of the server M01.
D _m and D _v are averages of gradations in the mark area and the blank area, respectively. Using these, the position where (D _m −P ₃ × D _v ) was the maximum for each color component was determined as the mark position.
P ₃ in Equation 5 is a cell determination parameter and is managed by the process control means 326.

As the scanning range, the range of ½ of the distance to the adjacent mark is targeted in the Row direction and the Column direction with the mark position assumed from the cell region calculation P201 step as the center. The cell area was scanned for each color component.
A series of processes related to the cell area scan P202 is shown in the flowchart of FIG. As shown in FIG. 24, cell indices for each color component were obtained from all data cells.

<Reference information acquisition / verification P203>
In the step of reference information acquisition / verification P203, reference information is acquired from a cell whose display is fixed in advance. At that time, the cell index acquired in the step of cell area scan P202 was used. Moreover, the acquired reference information was verified and the validity of the assumed two-dimensional code was evaluated.
The acquisition of reference information according to the present embodiment includes a step of determining a position in the cell region scan P202 and a step of acquiring cell gradation at the position and acquiring it as reference information (reference information acquisition / verification P203). The process was divided into steps.
The reference information acquisition / verification P203 of this embodiment was performed by the following method.

In this embodiment, when the reference information is acquired, the cell indices of the reference mark 030 and the positioning mark 020 are used (FIG. 3). Thereby, reference information of white Rw, cyan Rc, magenta Rm, yellow Ry, red Rr, green Rg, and blue Rb was obtained from the reference marks (030W, 030C, 030M, 030Y, 030R, 030G, 030B). Further, black Rk reference information was obtained from the positioning mark (020).
The reference information to be acquired is composed of cell indexes of a plurality of color components. In the present embodiment, for example, the value of the CMY component is acquired from the reference mark Rx of a certain color component as (Rx _c , Rx _m , Rx _y ). The acquired reference information is stored in the memory area of the server M01.
In FIG. 25, reference information (Rw, Rc, Rm, Ry, Rr, Rg, Rb, Rk) is plotted in a CMY color space configured with the values of the respective CMY components as axes. As shown in FIG. 25, the reference information affected by the input / output is not distorted but the three-dimensional figure connecting the vertices is a regular cube.

In this embodiment, the reference information is verified by evaluating whether the gradation of the reference information (Rw, Rc, Rm, Ry, Rr, Rg, Rb, Rk) is appropriate for each color component held in the image data.
In Table 6, for each color component, the combination of presence / absence of the corresponding color component is classified and displayed so that the presence / absence of other color components is common.
Table 7 shows the gradation difference between the reference information having the color component and the reference information not having the color component for the combination of presence / absence of each color component in Table 6. When the reference information is appropriate, each index (tone difference) shown in Table 7 takes a positive value.
In this embodiment, as the assumed two-dimensional code, the case where all the indexes in Table 7 are positive is determined as “appropriate”, and the case where even one negative exists is determined as “inappropriate”. In addition, when it was determined as “inappropriate” by the evaluation, a positioning error E2-1 was set.
The error detected in the step of reference information acquisition / verification P203 of the cell determination unit 323 is output to the process control unit 341.

<Cell display determination P204>
In the step of cell display determination P204, each cell is determined and the display is specified. At that time, the cell index acquired in the step of the cell area scan P202 and the reference information acquired in the step of the reference information acquisition / verification P203 were used.
In the determination of the cell display of this embodiment, the step of determining the position by the cell region scan P202 and the step of acquiring the cell gradation at the position and determining the display (cell display determination P204) are divided into separate steps. Carried out.
The cell display determination P204 of the present embodiment was performed by the following method.

The cell was determined by substituting the cell index into the determination formula (Equation 6) in each cell. Thereby, the presence or absence of a mark was determined for each color component. That is, in the judgment formula: Jd in Equation 6, when Jd ≧ 0, it is considered that the mark of the corresponding color component exists. When Jd <0, it was considered that no mark was present.
In Equation 6, the cell index (Jm _c , Jm _m , Jm _y ) of each color component is substituted for the variable (x, y, z). However, the value of the color component to be determined is substituted for the variable x, and the values of the other color components are substituted for the variables y and z, respectively. Table 8 shows the relationship between the variable (x, y, z) and the corresponding color component for each color component to be determined.

B, c, and d in Equation 6 are calculated using reference information (Rw, Rc, Rm, Ry, Rr, Rg, Rb, Rk) for each color component to be determined.
(X _i , y _i , z _i ) was calculated based on the two reference information classified according to the presence / absence of the color component to be determined by the combinations shown in Table 6. For Σ, the sum was calculated for all four combinations shown in Table 6.
Equation 7 shows the mathematical formula used for calculating (x _i , y _i , z _i ).
In _Equation 7, (x _1i , y _1i , z _1i ) is reference information R ₁ having a color component to be determined, and (x _0i , y _0i , z _0i ) is reference information R having no color component. ₀ was substituted for each. However, (x _1i , y _1i , z _1i ) and (x _0i , y _0i , z _0i ) were obtained using the relationship in Table 8 as with the variables (x, y, z).
P ₄ in Equation 7 is a cell determination parameter and is managed by the process control means 326.

Hereinafter, Equation 6, which is the determination formula of this embodiment, will be described. FIG. 26 is an example in which the relationship between the solid figure (FIG. 25) having the reference information at the apex and the determination plane (Jd = 0) of Equation 6 is displayed in the CMY color space. The determination surface of FIG. 26 is used to determine the presence or absence of a C component mark. When the cell index is plotted on the positive side in the axial direction of the C component (Jd ≧ 0), there is a mark, and the negative side (Jd <0). It is determined that there is no mark.
The determination surface of FIG. 26 classifies the reference information into two sets according to the presence / absence of the color component to be determined according to the combinations shown in Table 8. At the same time, the determination plane in FIG. 26 shows that the four combinations (Rw, Rc), (Ry, Rg), (Rm, Rb), and (Rr, Rk) of the same combination of other color components are between two points. It means that it intersects with connecting line segments (I ₁ , I ₂ , I ₃ , I ₄ ).
The determination plane is not limited to a plane as shown in FIG. For example, a quadratic curved surface may be used, and the determination formula in that case is a quadratic formula.

  A series of processes related to the cell display determination P204 is shown in the flowchart of FIG. As shown in FIG. 27, the determination of cell display was performed for all data cells for each color component.

<Decoding means>
The decoding unit 324 restores the display of the cell specified by the cell determination unit 323 to a bit string based on a predetermined rule. The restoration to the bit string was realized by performing the reverse process of the encoding means 221. A conceptual diagram of bit string restoration in this embodiment is shown in FIG.
In FIG. 28, “with mark” corresponds to “1” and “without mark” corresponds to “0” for the cell display (110C, 110M, 110Y) specified for each color component. At that time, the code data D20 was obtained by the reverse process using the allocation rule used in the encoding means 221.

<Data conversion / verification means>
The data conversion / verification unit 325 acquires the record number D00 of the database from the code data D20 acquired by the decoding unit 324. The data conversion / verification unit 325 is realized by performing the reverse process of the data conversion unit 222 (FIG. 9). However, the code data D20 may include a data error.

The data D03 is obtained by data separation (C20) and bit position decoding (C03) with respect to the code data D20, and may include a data error. The data D03 is subjected to error correction code decoding processing (C02) to obtain data D02. As a result, the error of the data D03 is corrected. If the error cannot be corrected, error detection is performed. If an error cannot be corrected and an error is detected, it is detected as a data error. In this embodiment, the data error is a cell determination error E3-1.
Data D02 is subjected to encryption decryption processing (C01), and data D01 is obtained. The acquired data D01 verifies a data error using redundant bits added when the two-dimensional code is issued. In this embodiment, the match between the bit string recorded in the database 120 and the upper 10 bits of the bit string D01 is verified. If the redundant bits do not match, an error is detected as a data error.
The error detected by the data conversion / verification unit 325 is output to the process control unit 341.

<Data output part>
The data output unit 330 outputs the bit string obtained by the two-dimensional code decoding unit 320. In this embodiment, the record number D00 of the database 120 is output to the management program of the database 120. Further, the output record number D00 is collated with the database 120, and an error is detected when there is an inconsistency.
As shown in FIG. 14, the data output unit 330 of this embodiment includes data output means 331. The data output unit 331 is realized by executing a program prepared in advance in the server M01. The decoding of the two-dimensional code and the database management in the data output means 331 may be performed by different computers. In this case, information is transmitted and received between the computers. The existing communication technology is used for the communication at that time.

The management program of the database 120 searches the database and extracts a record that matches the record number D00. Thereby, the stored content is specified with reference to the address described in the record. Thereafter, the content is subjected to an operation according to the operation type (Table 1) described in the record, such as being transmitted to the two-dimensional code acquisition device M03.
First example of operation: In the example of transmission to the mobile terminal (Table 1: A000), the content is returned using the mail function. After the content is received by the mobile terminal that is the two-dimensional code acquisition device M03, the content is displayed on the display and used by the user. Further, as general digital information, processing by a user, transfer to another device, and the like may be performed.

An inconsistency exists in a record extracted by database search, and it was detected as an error. As shown in Table 2, the inconsistency of the present embodiment is managed for each record by providing a field for recording the status of the two-dimensional code (1 = “restorable”, 0 = “not possible”) in the database.
The database of this embodiment limits the number of records with status = “1” (recoverable) out of the total number of records. As a result, a record of at least 10 bits or more is set to status = “0” (cannot be restored). In this case, error detection is possible, and security of record management is ensured.
The error detected by the data output means 331 was output to the process control means 341.

<Process control unit>
The process control unit 340 controls processing of errors detected in the restoration process. At that time, error analysis is attempted by changing the analysis parameters and repeating the restoration process. If the error cannot be avoided, an error is output to the two-dimensional code acquisition device M03 that has transmitted the two-dimensional code.
As shown in FIG. 14, the process control unit 340 according to this embodiment includes process control means 341. The process control unit 341 is realized by executing a program prepared in advance in the server M01.

An error in this embodiment is detected by the two-dimensional code input unit 311, the cell determination unit 323, the data conversion / verification unit 325, and the data output unit 331. Table 9 displays the error type, the determination condition, the error reason, and the processing for the error in the error. As shown in Table 9, the process control unit 341 of the present embodiment performs processing determined for each error type.
A plurality of levels were prepared for positioning parameters and cell determination parameters, which are analysis parameters of this embodiment (Table 10).

When the positioning error E2-1 is detected as the error type, the positioning parameter is changed and the positioning by the positioning unit 321 is performed again. As positioning parameters, P ₁ in the number 3 of code area extraction P101 steps and P ₂ in the number 4 of code area scanning P103 steps were used in the positioning means 321.
In order to verify the rotation angle of the two-dimensional code in the image data, the rotation angle P ₀ was used as a positioning parameter. That is, in the case of level 1, it is not rotated, in the case of level 2, it is rotated 90 ° clockwise, in the case of level 3 it is rotated 180 °, in the case of level 4 it is rotated 270 °, and each reference information is evaluated. As in this embodiment, even if the positioning marks are arranged rotationally symmetrically, the reference cell display is arranged so as not to be rotationally symmetric (rotational asymmetry), and the reference cell is restored when the two-dimensional code is restored. By verifying, it is possible to specify the rotation direction of the two-dimensional code in the image data.

FIG. 29 shows a flowchart in the case where the positioning error E2-1 is detected in the cell determination means 323. The positioning is repeated until the positioning error E2-1 is not detected or a predetermined flow is completed. Thereby, when the positioning error E2-1 is not detected, the process after the decoding means 324 is entered. On the other hand, when the flow ends, the restoration process is stopped and an error is output.
Table 11 shows the order of setting the positioning parameters (P ₁ and P ₂ ). However, the repetition of the level 1 to 4 of the positioning parameter P ₀ was applied to each of the settings in Table 11 (repetition order 1 to 5). In this embodiment, when the series of settings (repetition order 1 to 5) shown in Table 11 is completed, the repetition of positioning is ended.

When the cell determination error E3-1 is detected as the error type, the cell determination parameter is changed, and the cell determination by the cell determination unit 323 is performed again. As cell determination parameters, the cell determination means 323 uses P ₃ in the number 5 of cell region scanning P202 steps and P ₄ in the number 7 of cell display determination P204 steps.

FIG. 30 is a flowchart in the case where the cell conversion error E3-1 is detected in the data conversion / verification unit 325. The cell determination is repeated until the cell determination error E3-1 is not detected or a predetermined flow ends. Thereby, when the cell determination error E3-1 is not detected, the process after the data output means 331 is entered. On the other hand, when the flow ends, the restoration process is stopped and an error is output.
Table 12 shows the order of setting the cell determination parameters (P ₃ and P ₄ ). In this embodiment, when the series of settings shown in Table 12 (repetition order 1 to 5) is completed, the cell determination is repeated.

The process control unit 341 according to the present embodiment outputs an error when the error avoidance is impossible. At that time, “error type” and / or “error reason” in Table 9 were transmitted to the two-dimensional code acquisition apparatus M03. Further, when the error type is E3-1 (cell determination error), the error is analyzed and the result is transmitted.
The determination conditions in Table 13 were used for error factor analysis. When the determination condition is satisfied, “error factor” and / or “imaging advice” in Table 9 were acquired.
For the error factor analysis (judgment conditions in Table 13), the positions of the positioning marks (four locations), reference information, and the like were used. These values were obtained in advance by a restoration process and stored in a memory area. However, the gradation of the black mark (black reference information) was obtained from the positioning mark in this embodiment. In addition, the gradation is acquired from the blank area existing around the code area, and is defined as “the gradation of the blank area”.
The error determination in Table 13 was performed in the order of the numbers shown in “rank”. When the conditions matched, the error analysis process was terminated and the cause of the error was identified.

In this embodiment, the error information (error type, error reason, error factor, imaging advice) acquired by the process control unit 341 is transmitted to the mobile terminal that is the two-dimensional code acquisition device M03. The transmitted error information is displayed as text on a display attached to the mobile terminal. As a result, the user operating the mobile terminal refers to the error information and determines how to handle the error.
When “error factor” and / or “imaging advice” are acquired by error analysis, the user refers to the error information and images the two-dimensional code again. In this case, the error factor is corrected by the user, and the two-dimensional code can be restored.
As “imaging advice” in this embodiment, the distance between the camera and the two-dimensional code at the time of imaging (including the zoom function), the imaging angle, the brightness at the time of imaging (including the light emission level of the flash and the display device), Described things related to focus (including macro mode) during imaging.

<2D code restoration flow>
In the two-dimensional code restoration process of this embodiment, an example of the operation of the server M01 and the portable terminal that is the two-dimensional code acquisition apparatus M03 and the communication performed between the apparatuses will be described below with reference to FIG. However, in the example of FIG. 31, it is assumed that content is transmitted to the mobile terminal M03 as the operation type.

S201: The server M01 waits for access from the portable terminal M03.
S202: User B images a two-dimensional code with portable terminal M03 having an imaging function.
S203: The portable terminal M03 transmits the image data of the two-dimensional code to the server M01.
S204: The server M01 decodes the two-dimensional code of the received image data and acquires the record number of the database 120. If it cannot be decoded, error information is transmitted to the portable terminal M03 in step S206.
S205: The record with the record number is accessed to obtain the operation type and the content storage address.
S206: The content at the storage address is transmitted to the portable terminal M03. In the case of a decryption error, error information is transmitted instead of the content.
S207: The error content is displayed on the mobile terminal M03 based on the error information. At that time, if specified, an error factor in the restoration process and / or imaging advice is displayed.
S208: When the content is specified (no error), the mobile terminal M03 acquires the content, and the user B uses it according to the purpose.
S209: If the content cannot be identified (there is an error) because it cannot be decoded, the user B checks the error content displayed on the mobile terminal M03. At that time, if specified, the two-dimensional code is imaged with reference to error factors and / or imaging advice (S202), and the above-described flow is repeated again.

In this embodiment, data transmission / reception between the server M01 and the portable terminal M03 is performed by e-mail using a mail function provided in the portable terminal M03.
The server M01 obtains the two-dimensional code image data and the mail address of the portable terminal M03 by receiving the e-mail. For example, when the content specified by decoding the two-dimensional code is output to the portable terminal M03, an e-mail is transmitted to the acquired e-mail address.
The mail function of the portable terminal M03 used a mail transmission / reception means generally provided in the portable terminal M03. In general, it has a function of attaching a file in addition to a mail text, and transmits / receives two-dimensional code image data and electronic data content. The received mail is displayed with a list of titles, dates, etc. using a mailer provided in the portable terminal M03.
In the example where the content is text data, the text data is inserted into the mail body. For example, when the WEB address is transmitted to the user B, the WEB address is described in the mail body. User B designates this and becomes accessible from the portable terminal.

The server M01 of this embodiment has a mail server function using SMTP (Simple Mail Transfer Protocol) and POP (Post Office Protocol).
The server M01 performed a filtering process to delete illegal mail when receiving mail. As a filtering process of this embodiment, mail transmitted from other than the portable data carrier is excluded. At that time, the determination was made from the email address. E-mails from e-mail addresses registered in the unauthorized address list are also excluded. Further, the case where the image format and / or size (for example, format: JPEG, size: 10 Kbytes to 1 Mbyte) of the attached image data is not appropriate is excluded.

It is a figure which shows an apparatus structure. It is a figure which shows a two-dimensional code. It is a figure which shows the cell arrangement | positioning of a two-dimensional code. It is a figure which shows the partial area | region of the one-color component of a two-dimensional code. It is a figure which shows a mark cell. It is a figure which shows 2 continuous cells (horizontal direction, vertical direction). It is a figure which shows the cell allocated to the makeup | decoration mark. It is a figure which shows a two-dimensional code issue process. It is a figure which shows a data conversion flow. It is a figure which shows the conceptual diagram of cell display determination. It is a figure which shows the mark cell (one color component) of image data. It is a figure which shows the blank cell (one color component) of image data. It is a figure which shows the communication between the apparatuses of a two-dimensional code issuing process. It is a figure which shows a two-dimensional code restoration process. It is a figure which shows the mark cell (one color component) of image data. It is a figure which shows the step which comprises a positioning means. It is a figure which shows the position which acquires a gradation in the case of code area | region extraction. It is a figure which shows the example of the gradation distribution in a code area. It is a figure which shows the scanning of the image by collation of a collation pattern. It is a figure which shows the flowchart of code area scanning. It is a figure which shows the area | region of the determination by a determination formula. It is a figure which shows the straight line of positioning mark selection. It is a figure which shows the step which comprises a cell determination means. It is a figure which shows the flowchart of cell area scanning. It is a figure which shows the plot of the reference information in CMY color space. It is a figure which shows the determination surface in CMY color space. It is a figure which shows the flowchart of cell display determination. It is a figure which shows the conceptual diagram of a bit stream decompression | restoration. It is a figure which shows the flowchart at the time of positioning error detection. It is a figure which shows the flowchart at the time of a cell determination error detection. It is a figure which shows the communication between the apparatuses of a two-dimensional code restoration process.

001 ... Mark cell, 002 ... Blank cell 003 ... Mark area, 004 ... Blank area 008 ... Collation pattern 010 ... Data mark 010C, 010M, 010Y ... Data mark (cyan, magenta, yellow)
010R, 010G, 010B ... Data mark (red, green, blue)
010K, 010W ... Data mark (black, white)
020 ... Positioning mark 030 ... Reference mark 030C, 030M, 030Y ... Reference mark (cyan, magenta, yellow)
030R, 030G, 030B ... Reference mark (red, green, blue)
030K, 030W ... Reference mark (black, white)
040 ... makeup mark 040C, 040M, 040Y ... makeup mark (cyan, magenta, yellow)
040R, 040G, 040B ... makeup mark (red, green, blue)
040K, 040W ... Makeup mark (black, white)
100 ... 2D code, 101 ... 2D code (8x8 cells)
120 ... Database 200 ... Two-dimensional code issuing process 210 ... Data input unit 211 ... Data input unit 220 ... Two-dimensional code generation unit 221 ... Data conversion unit 222 ... Encoding unit 223 ... Image creation unit 224 ... Image conversion unit 230 2D code output unit 231 2D code output unit 300 2D code restoration process 310 2D code input unit 311 2D code input unit 320 2D code decoding unit 321 Image conversion unit 322 ... positioning means, 323 ... cell determination means 324 ... decoding means, 325 ... data conversion / verification means 330 ... data output unit, 331 ... data output means M01 ... server M02 ... content registration device M03 ... two-dimensional code acquisition device

Claims (4)

For a plurality of cells arranged two-dimensionally, a two-dimensional code in which a bit string is expressed by a combination of gradations in a plurality of color components constituting the display of the cell,
The cell display represents a bit string corresponding to the presence / absence combination of marks in each color component,
A mark for representing the bit string Te cells smell no in all color components, before symbols during which does not represent the bit string, the color between the blank area region and the mark to which the mark is displayed is not displayed The component gradations are displayed with contrast,
A two-dimensional code characterized by For a plurality of cells arranged two-dimensionally, a two-dimensional code in which a bit string is expressed by a combination of gradations in a plurality of color components constituting the display of the cell,
The cell display represents a bit string corresponding to the presence / absence combination of marks in each color component,
The color components between the marks for representing a bit string Te cell odor with by all the color components, marks representing the previous SL bit sequence, blank area region and the mark to which the mark is displayed is not displayed Displayed with a lower contrast of the gray level than other cells.
A two-dimensional code characterized by The display of the cell is represented by the mark arranged by surrounding each cell with the blank area,
The two-dimensional code according to claim 1 or 2. A two-dimensional code for issuing a two-dimensional code relating to a two-dimensional code in which a bit string is expressed by a combination of gradations of a plurality of color components constituting the display of a plurality of cells arranged two-dimensionally Issuing program,
The mark does not represent a prior SL bit string is provided with a contrast to the gradation of the color components between the blank area region and the mark to which the mark is displayed is not displayed,
And / or, mark representing the front Symbol bit string is provided to suppress than other cells contrast of gradation of the color components between the blank area region and the mark to which the mark is displayed is not displayed about,
A two-dimensional code issuing program characterized by