JP2010061217A - Two-dimensional code - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To more efficiently obtain a configuration capable of setting a reference area which becomes a standard of each color to be displayed on a cell, and capable of accurately separating a code area from a back ground in a two-dimensional code to be represented with colors. <P>SOLUTION: In the two-dimensional code 1, a plurality of cells "C" are two-dimensionally disposed within a rectangular area, and information encoded by color, density, or intensity of each cell is configured as a color code for color representation. The two-dimensional code 1 is provided with color reference patterns 21 to 27 which become to be standards of cell display colors to be used for each cell within the rectangular area. In the color reference patterns 21 to 27, the plurality of cells "C" are disposed with a matrix state, and at least a part of a cell string is configured as a boundary portion of the rectangular area. Moreover, the cell string configured as the boundary portion of the rectangular area in the color reference patterns 21 to 27 are configured by a predetermined color matrix for separating the rectangular area from the back ground of the rectangular area. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a two-dimensional code.

Conventionally provided two-dimensional codes generally have a configuration in which white cells and black cells are arranged in a matrix, but such two-dimensional codes have a situation in which it is difficult to increase the amount of information to be recorded. . Therefore, various color two-dimensional codes for expressing the cell display in color have been proposed at present, and the recording information has been densified. In addition, there exist a thing like patent document 1, 2 as a technique regarding such a color two-dimensional code, for example.
Japanese Patent No. 3923696 Japanese Patent No. 3996520

  In the color two-dimensional code as described above, it is required to accurately determine each color displayed in the cell. However, the reading result of each color is likely to vary depending on the printing environment and the reading environment, and if no measures are taken, an erroneous determination due to the variation is caused. In order to prevent such an erroneous determination, it is desirable to place a reference pattern to be a color determination reference in a specific area and determine each color based on the reference result of the reference pattern.

  On the other hand, in the above two-dimensional code, it is required to separate the code area and the background in order to clarify the area to be read as the two-dimensional code. In order to perform such separation accurately, it is desirable that a specific pattern that can be easily separated from the background is determined in advance and arranged at the boundary of the two-dimensional code.

  As described above, in the color two-dimensional code, it is desirable to arrange a pattern for separating color determination and a pattern for separating the code area from the background, and more data is recorded in the code area. In view of this, it is desirable to distribute patterns having these functions more efficiently.

  The present invention has been made to solve the above-described problems, and in a two-dimensional code expressed in color, a reference area serving as a reference for each color displayed in a cell can be provided, and the code area and the background can be provided. It is an object to more efficiently realize a configuration that can be separated from each other with high accuracy.

  In order to achieve the above object, the invention of claim 1 is a two-dimensional representation in which a plurality of cells are two-dimensionally arranged in a rectangular area, and the information encoded by the color, density, or luminance of each cell is expressed in color. A color reference pattern which is a code and serves as a standard of a cell display color used for each cell in the rectangular area, wherein the color reference pattern includes a plurality of cells arranged in a matrix and at least some of the cells A column is configured as a boundary portion of the rectangular region, and the cell column configured as a boundary portion of the rectangular region further includes a predetermined color array for separating the rectangular region and the background of the rectangular region It is characterized by comprising.

  According to a second aspect of the present invention, in the two-dimensional code according to the first aspect, the color reference pattern is configured in a matrix of 3 rows and 3 columns.

  The invention of claim 3 is the two-dimensional code according to claim 1 or claim 2, wherein a specific pattern for separating the rectangular area and the background is arranged along a boundary of the rectangular area, The cell row of the color reference pattern is configured as a part of the specific pattern.

  According to a fourth aspect of the present invention, in the two-dimensional code according to the third aspect, when the specific pattern captures the rectangular area and acquires an image of a predetermined color component, It is characterized by the structure comprised and the part comprised by other parts other than the said cell row | line | column so that it may become a continuous specific pattern.

  According to a fifth aspect of the present invention, in the two-dimensional code according to the fourth aspect, the other part of the specific pattern is determined to be a bright discrimination cell that is discriminated to be bright and dark in the image of the predetermined color component. The dark discrimination cells are alternately arranged in an alternating pattern, and the cell row is an alternating pattern that is continuous with the alternating pattern of the other portion in the image of the predetermined color component. It is comprised by these.

  According to a sixth aspect of the present invention, in the two-dimensional code according to the fourth aspect, the other portion of the specific pattern is a dark continuous pattern in which dark determination cells determined to be dark are continuous in the image of the predetermined color component. The cell row is configured to be a dark color continuous pattern continuous with the dark color continuous pattern of the other portion in the image of the predetermined color component.

  According to a seventh aspect of the present invention, in the two-dimensional code according to the first or second aspect, the color reference pattern includes at least cells at both ends of the cell column that capture the rectangular area and have a predetermined color component. It is configured as a dark discrimination cell that is determined to be dark in the image when the image is acquired.

  An eighth aspect of the invention is the two-dimensional code according to the seventh aspect, wherein all the cells constituting the cell column are configured as the dark discrimination cells in the color reference pattern.

  The invention according to claim 9 is the two-dimensional code according to any one of claims 4 to 8, wherein a prescribed corner portion of the rectangular area serves as a position reference of the cell in the rectangular area. A reference pattern is provided, and a plurality of the color reference patterns are arranged at corners other than the prescribed corners, and the color reference patterns are corners arranged at four corners of the color reference pattern. The cell is constituted by a dark discrimination cell that is determined to be dark in the image of the predetermined color component.

  According to a tenth aspect of the present invention, in the two-dimensional code according to any one of the first to ninth aspects, a plurality of the color reference patterns having the same color arrangement are provided in the rectangular area. Features.

  According to the first aspect of the present invention, since a color reference pattern serving as a standard of the cell display color used for each cell in the rectangular area is provided, it becomes easy to accurately determine the color of each cell at the time of reading. Furthermore, the cell array of the color reference pattern is configured as a boundary portion of the rectangular area, and is configured with a predetermined color arrangement for separating the rectangular area and the background, so that the code area and the background can be separated with high accuracy. Can be realized more efficiently.

  In the invention of claim 2, since the color reference pattern is configured in a matrix of 3 rows and 3 columns, it is appropriate to use 3 cell columns for separating the background from the background while making the color reference pattern compact. Can be configured.

  In the invention of claim 3, the specific pattern for separating the rectangular area and the background is arranged along the boundary of the rectangular area, and the cell sequence of the color reference pattern is configured as a part of the specific pattern. Yes. In this way, the rectangular area and the background can be separated using not only the color reference pattern but also other parts constituting the specific pattern (parts other than the color reference pattern), and can be separated more accurately and satisfactorily.

  According to a fourth aspect of the present invention, when an image of a predetermined color component is acquired by capturing an image of a rectangular area, a portion constituted by a cell row and a portion other than the cell row are continuously specified in the image. It is configured to be a pattern. In this way, a specific pattern that can specify the boundary of the rectangular area when an image of a predetermined color component is acquired is configured, and the rectangular area can be separated with higher accuracy based on the specific pattern. In particular, the specific pattern is not constituted only by the color reference pattern or only by the other part other than the color reference pattern, but the specific pattern is constituted by continuing these, so that the color reference pattern can be arranged efficiently. A specific pattern can be provided longer.

  According to a fifth aspect of the present invention, there is provided a light discrimination cell in which the other part of the specific pattern (a part other than the cell row forming a part of the color reference pattern) is determined to be bright in the image having a predetermined color component, The dark discrimination cells to be discriminated are alternately arranged in an alternating pattern. In this way, it becomes easy to specify the rectangular area with high accuracy while suppressing the influence of the background color. In particular, in an image of a predetermined color component, the color reference pattern is formed at the boundary portion because the cell row forming a part of the color reference pattern and the other portion other than the cell row are configured to be an alternating pattern. The alternating pattern can be expressed in a wider area while arranging the rectangular areas, and the rectangular areas can be separated with higher accuracy.

  According to a sixth aspect of the present invention, the other part of the specific pattern is configured to be a dark continuous color pattern in which dark determination cells determined as dark are continuous in an image of a predetermined color component. In this way, it becomes easier to specify the boundary of the rectangular area more clearly when the background color is light in the image of the color component. In particular, in an image of a predetermined color component, since it is configured to be a dark continuous pattern in which a cell row that forms part of the color reference pattern and a portion other than the cell row are continuous, color reference is made at the boundary portion. A dark continuous pattern can be expressed in a wider area while arranging patterns, and rectangular areas can be separated with higher accuracy.

  According to the seventh aspect of the present invention, at least the cells at both ends of the cell row of the color reference pattern (the cell row configured as the boundary) are determined to be dark in the image when the image of the predetermined color component is acquired ( (Dark discrimination cell). In this way, when the background color is light in the image of the predetermined color component, it becomes easy to distinguish the background and the cell row from one end to the other end of the cell row, and thus the background and the rectangular region are separated. It becomes easy to separate accurately.

  In the invention of claim 8, all the cells of the cell row of the color reference pattern (cell row formed as the boundary portion) are configured as dark discrimination cells. In this way, when the background color is light in the image of the predetermined color component, it becomes easier to distinguish the entire cell row and the background, and the rectangular area can be more accurately separated.

  According to the ninth aspect of the present invention, since the reference pattern serving as the position reference of the cell in the rectangular area is provided at the specified corner of the rectangular area, the specified corner can be specified with high accuracy by the reference pattern. become. On the other hand, since the color reference patterns are arranged for corners other than the prescribed corners, these corners can be specified by the color reference pattern. Furthermore, the corner cells of each color reference pattern (respective cells arranged at the four corners of each color reference pattern) are configured as dark discrimination cells (cells that are determined to be dark in an image of a predetermined color component). Therefore, dark colors are arranged at the corners of the rectangular area in the image of the predetermined color component, and each corner can be more accurately specified when the background color is light in the image of the color component. Become.

  According to a tenth aspect of the present invention, a plurality of color reference patterns are provided in the same color arrangement. In this way, the cell display color standard can be obtained using any of the plurality of color reference patterns, which is advantageous when, for example, it is difficult to read any of the patterns. Furthermore, since they are configured with the same color arrangement, it is not necessary to use a complicated reading method or reading information to read each pattern, and the reading can be further simplified.

[First embodiment]
Hereinafter, a first embodiment embodying a two-dimensional code of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram schematically illustrating a two-dimensional code according to the first embodiment. FIG. 2A is an explanatory diagram for explaining a color reference pattern used in the two-dimensional code of FIG. 1, and FIG. 2B schematically shows a light / dark configuration of the color reference pattern when a green component image is acquired. It is explanatory drawing demonstrated. FIG. 3 is an explanatory diagram schematically illustrating a light / dark configuration when a green component image is acquired for the two-dimensional code of FIG. 1. FIG. 4A is an explanatory diagram for explaining the relationship between each color and brightness in the red component image, and FIG. 4B is an explanatory diagram for explaining the relationship between each color and brightness in the green component image. ) Is an explanatory diagram for explaining the relationship between each color and light and dark in a blue component image. FIG. 5 is a flowchart illustrating a reading process for reading the two-dimensional code of this embodiment.

  As shown in FIG. 1, the two-dimensional code 1 according to the present embodiment includes a plurality of cells C arranged in a matrix, and includes a plurality of code blocks 10, a first specific pattern 2, The configuration includes two specific patterns 3 and 4. This two-dimensional code 1 is configured as a cell aggregate in which cells C having a square outer shape are aggregated and arranged in a matrix. In the example of FIG. 1, the number of cells is the same number (35 cells × 35 cells). ). In addition, the code area (area where the cell C is arranged) constituting the two-dimensional code 1 is a rectangular area whose outer shape is rectangular (in the example of FIG. 1, a square area whose outer shape is square).

  In FIG. 1, only some of the cells are denoted by reference symbol C, and the other cells are omitted. In FIG. 1, the positions of some error correction code blocks 12 are conceptually indicated by alternate long and short dash lines, and other error correction code blocks are not shown. Further, the positions of some data code blocks 11 are conceptually shown by two-dot chain lines, and the other data code blocks 11 are not shown. Further, in FIG. 1, an area (data recording area) in which data is recorded is conceptually indicated by a broken line AR1, and a specific cell configuration (specific cell configuration of each code block 10) in the data recording area AR1. Etc.) are omitted.

  The two-dimensional code 1 of the present embodiment is configured as a so-called color code using three or more types of cells having different colors, densities, or luminances. In FIG. 1, black cells, white cells, A configuration using eight color cells of a red cell, a green cell, a blue cell, a cyan cell, a magenta cell, and a yellow cell is shown. Throughout this embodiment and other embodiments, the black cell is indicated by Cb, the white cell is indicated by Cw, the green cell is indicated by Cg, the red cell is Cr, the blue cell is Cu, the yellow cell is Cy, and the cyan cell. Is represented as Cn, and the magenta cell as Cm.

  The code block 10 that constitutes a part of the two-dimensional code 1 is a set of a plurality of cells C. In the two-dimensional code 1 of FIG. 1, the data code block 11 and the error correction code block 12 include It is divided. The data code block 11 and the error correction code block 12 are both unmasked blocks that have not been subjected to mask processing, and can be decoded without the need for cancellation of mask processing or the like.

  The data code block 11 is a block in which encoded data (data code word) obtained by encoding data to be decoded is expressed by a plurality of cells. In the example of FIG. 1, a plurality of cells are gathered in a matrix. It has a configuration. Each cell constituting the data code block 11 is selected and used from a plurality of predetermined types of cells (the above-described eight color cells in the example of FIG. 1). In FIG. 1, the data code block 11 in which eight cells are arranged in a matrix of 4 rows and 2 columns is conceptually illustrated by a two-dot chain line, but the number of cells and the block configuration of the data code block 11 are illustrated. May be other than this.

  Each data code block 11 is composed of an array of cells corresponding to encoded data (data code words) to be decoded. Specifically, the cell display color is associated with a numerical value. For example, the first color “white” for the data value “0” and the second color “red” for the data value “1”. ”, The third color“ green ”for the data value“ 2 ”, the fourth color“ blue ”for the data value“ 3 ”, and the fifth color“ magenta ”for the data value“ 4 ”. The sixth color “yellow” for the data value “5”, the seventh color “cyan” for the data value “6”, the eighth color “black” for the data value “7”, Are associated with each other.

  The error correction code block 12 is composed of error correction code words for performing error correction of the data code block 11. The error correction code word constituting the error correction code block 12 is generated based on the encoded data (data code word) constituting the data code block 11. As a method for generating an error correction code word based on a data code word, for example, a known Reed-Solomon error correction method can be used.

  In the present embodiment, an error correction code word generation method (JISX0510: 2004, 8.5 error correction) defined in JIS X0510: 2004 is used as a method for generating an error correction code word based on a data code word. . In this method, the error correction code word is represented by a polynomial g (x) used in error correction detection and correction (JISX0510: 2004 appendix A) after the data code word for the data code block 11 is represented in binary. Is the remainder obtained by dividing the data code word. The error correction code block 12 is configured as a block in which the error correction code word generated in this way is expressed by a plurality of cells. Here, the error correction code word is generated using the method defined in JISX0510, but the method of generating the error correction code word is not limited to this, and various known methods can be used.

  The 1st specific pattern 2 is arrange | positioned in the predetermined | prescribed corner | angular part 5a among four corner | angular parts (part which comprises the corner | angular in a rectangular area) 5a-5d provided in the rectangular area of the two-dimensional code 1. FIG. is there. In the example of FIG. 1, the outer shape of the first specific pattern 2 is configured in a rectangular shape (specifically, a square shape), and a prescribed corner portion 5 a in the rectangular region is defined by two sides that form the outer edge of the first specific pattern 2. The angular position of is determined. The first specific pattern 2 functions as an element for specifying the position of each cell C in the rectangular area. Specifically, when the two-dimensional code 1 is read by the optical information reader. It is used to specify the position of the prescribed corner 5a in the obtained image data, and is used to specify the direction of the two-dimensional code 1 in the image data. Throughout this specification, the first specific pattern 2, the second specific pattern 3, 4 and the color reference pattern described later are constant regardless of the data (data to be decoded) included in the two-dimensional code. It is configured as a pattern.

  The first specific pattern 2 has one cell of the first color (black cell 2a) arranged at the center, and a plurality of types of cells 2b to around the first color cell (black cell 2a). 2i surrounds the rectangle. Further, the annular cell group (multi-color cell group) is surrounded by a first color cell (black cell 2j) in an annular and rectangular shape, which is configured as the outermost cell group. ing. The outermost cell group has an outer shape of a rectangular shape (square shape), and the outer shape of the first specific pattern 2 as a whole is a rectangular shape (square shape).

  The second specific patterns 3 and 4 are boundary sides (first boundary sides 6 a, 6 a, and 4) that are in contact with the first specific pattern 2 among the four sides (four boundary sides 6) forming the boundary of the code region (rectangular region). 6b). The second specific patterns 3 and 4 are used to separate the code area (rectangular area) of the two-dimensional code 1 from the background. By recognizing 4, the positions of the first boundary sides 6a and 6b can be specified.

  The second specific pattern 3 is adjacent to the end of the first specific pattern 2 and is disposed adjacent to the first boundary side 6a over the entire region from the adjacent position to the corner 5b. The second specific pattern 3 is partly constituted by the color reference patterns 21 and 22, and the other part other than the color reference patterns 21 and 22 is constituted by the black and white alternating patterns 3a and 3b composed of white cells and black cells. Has been.

  The black-and-white alternating pattern 3 a arranged between the first specific pattern 2 and the color reference pattern 21 has a white cell adjacent to the first specific pattern 2 as one end, and a white cell adjacent to the color reference pattern 21 It is composed of 11 cells as the other end, and is arranged in a line along the first boundary side 6a. In the black-and-white alternating pattern 3a, a black cell is disposed adjacent to a white cell at one end (a white cell adjacent to the first specific pattern 2), and a white cell is disposed adjacent to the black cell. The white cells and the black cells are alternately arranged for each cell.

  The same applies to the black-and-white alternating pattern 3b arranged between the two-color reference patterns 21 and 22. The white cell adjacent to the color reference pattern 21 is one end, and the white cell adjacent to the color reference pattern 22 is the other end. It is composed of 11 cells as a part, and is arranged in a line along the first boundary side 6a. The black-and-white alternating pattern 3b is also white in a form in which a black cell is arranged adjacent to a white cell at one end (a white cell adjacent to the color reference pattern 21), and a white cell is arranged adjacent to the black cell. Cells and black cells are alternately arranged for each cell.

  Each of the color reference patterns 21 and 22 includes a plurality of cells arranged in a matrix (in the example of FIG. 1, a matrix of 3 rows and 3 columns). In the example of FIG. , 22 have the same configuration. These color reference patterns 21 and 22 are patterns that serve as a standard for the cell display color used for each cell in the rectangular area. As shown in FIG. Black, white, red, green, blue, magenta, cyan, yellow). In FIG. 2A, only the color reference pattern 21 is shown, but since the color reference pattern 22 has the same configuration, an enlarged view of the color reference pattern 22 is omitted.

  As shown in FIG. 1, the color reference pattern 21 is disposed adjacent to a substantially central position of the first boundary side 6a, and a cell adjacent to the first boundary side 6a (that is, a part of the outer edge is the first). A cell row 30 including cells 21a, 21b, and 21c) arranged at the position of the boundary side 6a is configured as a boundary portion of the rectangular area. The cell row 30 including the cells 21a, 21b, and 21c is configured with a predetermined color arrangement (described later) for separating the rectangular area and the background of the rectangular area, and a part of the second specific pattern 3 The one end side is adjacent to the black-and-white alternating pattern 3a and the other end side is adjacent to the black-and-white alternating pattern 3b.

  The color reference pattern 22 is disposed adjacent to the end of the first boundary side 6a, and a cell adjacent to the first boundary side 6a (that is, a part of the outer edge is disposed at the position of the first boundary side 6a. The cell row 31 including the cells 22a, 22b, and 22c) is configured with a predetermined color arrangement (described later) for separating the rectangular area and the background of the rectangular area. The cell row 31 is configured as a part of the second specific pattern 3, and one end side is adjacent to the black and white alternating pattern 3b, and the other end portion is configured as a corner 5b of a rectangular region. The color reference pattern 22 has a function as an end pattern indicating the end of the first boundary side 6a.

  The second specific pattern 4 is adjacent to the end of the first specific pattern 2 and is disposed adjacent to the first boundary side 6b over the entire region from the adjacent position to the corner 5c. The second specific pattern 4 is partly constituted by the color reference patterns 23 and 24, and the other part other than the color reference patterns 23 and 24 is constituted by the black and white alternating patterns 4a and 4b composed of white cells and black cells. Has been.

  The black-and-white alternating pattern 4 a arranged between the first specific pattern 2 and the color reference pattern 23 has a white cell adjacent to the first specific pattern 2 as one end, and a white cell adjacent to the color reference pattern 23. It is composed of 11 cells as the other end, and is arranged in a line along the first boundary side 6b. In this black and white alternating pattern 4a, a black cell is disposed adjacent to a white cell at one end (a white cell adjacent to the first specific pattern 2), and a white cell is disposed adjacent to the black cell. The white cells and the black cells are alternately arranged for each cell.

  The same applies to the black-and-white alternating pattern 4b arranged between the two color reference patterns 23 and 24. The white cell adjacent to the color reference pattern 23 is one end, and the white cell adjacent to the color reference pattern 24 is the other end. It is composed of 11 cells as a part, and is arranged in a line along the first boundary side 6b. Also in this black and white alternating pattern 4b, white cells are arranged in such a manner that a black cell is arranged adjacent to a white cell at one end (a white cell adjacent to the color reference pattern 23) and a white cell is arranged adjacent to the black cell. Cells and black cells are alternately arranged for each cell.

  Each of the color reference patterns 23 and 24 is formed by arranging a plurality of cells in a matrix (a matrix of 3 rows and 3 columns). In this embodiment, the two color reference patterns 23 and 24 have the same configuration. Furthermore, these color reference patterns 23 and 24 have the same configuration as the above-described color reference patterns 21 and 22. These color reference patterns 23 and 24 are also patterns that serve as a standard for the cell display color used for each cell in the rectangular area, and the all cell display colors used in the two-dimensional code 1 are the same as the color reference patterns 21 and 22 described above. (Black, white, red, green, blue, magenta, cyan, yellow) are displayed.

  As shown in FIG. 1, the color reference pattern 23 is disposed adjacent to a substantially central position of the first boundary side 6b, and a cell adjacent to the first boundary side 6b (that is, a part of the outer edge is the first). A cell row 32 composed of cells 23a, 23h, 23g) located on the boundary side 6b is configured as a boundary portion of the rectangular area. The cell row 30 is configured with a predetermined color array (described later) for separating the rectangular area and the background of the rectangular area, and is configured as a part of the second specific pattern 4. The black-and-white alternating pattern 4a is adjacent, and the other end is adjacent to the black-and-white alternating pattern 4b.

  The color reference pattern 24 is arranged adjacent to the end of the first boundary side 6b, and a cell adjacent to the first boundary side 6b (that is, a part of the outer edge is located on the first boundary side 6b). 24a, 24h, and 24g) is configured with a predetermined color arrangement (described later) for separating the rectangular area and the background of the rectangular area. The cell row 33 is configured as a part of the second specific pattern 4, and one end side is adjacent to the black and white alternating pattern 4b, and the other end portion is configured as a corner 5c of a rectangular region. Note that the color reference pattern 24 has a function as an end pattern indicating the end of the first boundary side 6b.

Next, the “predetermined color arrangement for separating the rectangular area and the background of the rectangular area” will be described.
When the color reference pattern 21 used in the two-dimensional code 1 captures a rectangular area and acquires an image of a predetermined color component, in the image of the predetermined color component, other than the cell column 30 and the cell column 30 The portions (that is, the black and white alternating patterns 3a and 3b) are configured to be a continuous specific pattern.

Hereinafter, a configuration example when the “predetermined color component image” is the “green component image” will be described.
In the green component image (G image), there is no significant difference between the signal level of “green” and the signal levels of “white”, “yellow”, and “cyan”, and these levels are similar to “bright”. On the other hand, in the green component image, there is no significant difference between the signal levels of “black”, “red”, “blue”, and “magenta”, which are levels similar to “dark”. FIG. 4B shows the correspondence between each color and light and dark in the green component image.

  In the present embodiment, the specific pattern 3 is configured by paying attention to the above properties. First, as shown in FIG. 3, the other portions (black and white alternate patterns 3a and 3b) other than the cell rows 30 and 31 are bright discrimination cells (cells determined to be bright in the green component image) in the green component image. The dark discrimination cells (cells that are discriminated as dark in the green component image) are arranged in an alternating pattern 3a'3b 'in which cells are alternately arranged. In the example of FIG. 1, the black cells constituting the black and white alternating patterns 3a and 3b are dark discrimination cells in the green component image, and the white cells are light discrimination cells in the green component image.

  In addition, as shown in FIG. 3, the cell row 30 is configured to be an alternating pattern 30 ′ continuous with the alternating pattern 3 a ′ of the black and white alternating pattern 3 a in the green component image. It is configured so that “is continuous with the alternating pattern 3b of the black and white alternating pattern 3b”.

  In the configuration of FIG. 1, the end portion on the cell row 30 side in the black-and-white alternating pattern 3a is composed of white, black, white, and the end is composed of white cells, and the alternating pattern 3a ′ shown in FIG. The cell array 30 has an end side that is bright, dark, and bright, and an end portion that is configured by a light discrimination cell. Accordingly, the end cell 21a on the black and white alternating pattern 3a side in the cell row 30 is a black color that becomes a dark discrimination cell in the green component image so that the alternating pattern 30 ′ of the cell row 30 is dark, light, and dark. Consists of cells, the subsequent cell 21b is configured by a cyan cell that is a light discrimination cell in the green component image, and the subsequent end cell 21c is configured by a red cell that is a dark discrimination cell in the green component image is doing.

  As shown in FIGS. 2B and 3, the alternating pattern 30 ′ of the cell row 30 in the green component image is dark (dark discrimination cell 21 a ′), bright (bright discrimination cell 21 b ′), dark ( The dark discrimination cell 21c ′) and the end portion are constituted by the dark discrimination cell 21c ′. Therefore, the configuration on the cell row 30 side of the black and white alternating pattern 3b is white, black, white, and so on so that the alternating pattern 3b 'of the black and white alternating pattern 3b becomes the following light, dark, light, and so on. They are lined up (FIG. 1).

  As shown in FIG. 1, the black-and-white alternating pattern 3b is composed of white, black, white on the end side on the cell row 31 side and white cells on the end side, and the green shown in FIG. In the component image, the alternating pattern 3b ′ of the black-and-white alternating pattern 3b is composed of... Bright, dark, and bright on the end side on the cell row 31 side, and the end is composed of light discrimination cells. Accordingly, the end cell 22a on the black and white alternating pattern 3b side in the cell row 31 is replaced with the dark discrimination cell 22a ′ in the green component image so that the alternating pattern 31 ′ of the cell row 31 is dark, light, and dark. And the subsequent cell 22b is a cyan cell that becomes the light discrimination cell 22b 'in the green component image, and the subsequent end cell 22c is the dark discrimination cell 22c' in the green component image. It is comprised by the red cell which becomes.

  Further, the cell row 31 is configured such that the end on the corner 5b side in the alternating pattern 31 ′ configured by the green component image becomes the dark discrimination cell 22c ′, and the dark pattern of the alternating pattern 31 ′. The corner 5b of the rectangular area is indicated by the discrimination cell 22c ′.

  Because of this configuration, when a green component image as shown in FIG. 3 is acquired, the regularity of the alternating pattern in which light and dark are alternately arranged for each cell is adjacent to the first specific pattern 2. From the position to the position of the corner 5b, the entire first boundary side 6a can be easily specified.

  In addition, the color reference pattern 22 includes a cell column 39 including cells adjacent to the second boundary side 6c (that is, cells 22c, 22d, and 22e in which a part of the outer edge is disposed at the position of the second boundary side 6c). ing. The cell row 39 is configured to have an alternating pattern 39 ′ in which dark discrimination cells 22c ′ and 22e ′ are arranged at both ends and a light discrimination cell 22d ′ is arranged in the center in the green component image shown in FIG. Has been. Accordingly, the positions of the first boundary side 6a and the second boundary side 6c are accurately indicated by the alternating pattern 31 ′ and the alternating pattern 39 ′, respectively, and the corner position of the corner 5b is determined by the dark discrimination cell 22c ′ at the top. In this case, the boundary near the corner 5b of the rectangular area can be specified more accurately.

  The second specific pattern 4 is configured in the same manner. First, with respect to the other portions (black and white alternate patterns 4a and 4b) other than the cell rows 32 and 33, the light discrimination cell (the cell that is discriminated to be bright in the green component image) and the dark discrimination in the green component image shown in FIG. The cells (cells that are determined to be dark in the green component image) are alternately arranged in an alternating pattern 4a'4b '. In the example of FIG. 1, the black cells constituting the black-and-white alternating patterns 4a and 4b are dark discrimination cells in the green component image, and the white cells are bright discrimination cells in the green component image.

  In addition, the cell row 32 is configured to be an alternating pattern 32 ′ that is continuous with the alternating pattern 4a ′ of the black and white alternating pattern 4a in the green component image shown in FIG. 3, and further, the alternating pattern 32 ′. Is also continuous with the alternating pattern 4b ′ of the black and white alternating pattern 4b.

  In the configuration of FIG. 1, the end side on the cell row 32 side in the black and white alternating pattern 4 a is composed of white, black, white, and the end is composed of white cells, and the green component image shown in FIG. The alternating pattern 4a ′ is composed of light, dark, and light, and the end is composed of a light discrimination cell. Therefore, the end cell 23a on the black and white alternating pattern 3a side in the cell row 32 is replaced with the dark discrimination cell 23a ′ in the green component image so that the alternating pattern 32 ′ of the cell row 32 becomes dark, light, and dark. And the subsequent cell 23h is composed of a yellow cell that becomes the light discrimination cell 23h 'in the green component image, and the subsequent end cell 23g is a dark discrimination cell 23g' in the green component image. It is comprised by the blue cell which becomes.

  Further, as shown in FIG. 3, the alternating pattern 32 ′ of the cell row 32 in the green component image is composed of dark, bright, and dark, and the end is composed of a dark discrimination cell 23g ′. Therefore, the configuration on the cell row 32 side in the black and white alternate pattern 4b is arranged such as white, black, white,... So that the alternating pattern 4b ′ of the black and white alternate pattern 4b becomes the following light, dark, and light. (FIG. 1).

  As shown in FIG. 1, the black-and-white alternating pattern 4b is composed of white, black, white on the end side on the cell row 33 side and white cells on the end side, as shown in FIG. Further, the alternating pattern 4b ′ of the black and white alternating pattern 4b configured in the green component image is composed of bright, dark, and bright on the end side on the cell row 33 side, and the end portion is defined by the light discrimination cell. It is configured. Therefore, the end cell 24a on the black and white alternating pattern 4b side in the cell row 33 is replaced with the dark discrimination cell 24a ′ in the green component image so that the alternating pattern 33 ′ of the cell row 33 is dark, light, and dark. And the subsequent cell 24h is composed of a yellow cell that becomes the light discrimination cell 24h ′ in the green component image, and the subsequent end cell 24g is a dark discrimination cell 24g ′ in the green component image. It is comprised by the blue cell which becomes.

  Further, the cell row 33 is configured such that the end on the corner portion 5c side in the alternating pattern 33 ′ configured by the image of the green component becomes the dark discrimination cell 24g ′, and the darkness of the alternating pattern 33 ′. The corner 5c of the rectangular area is indicated by the discrimination cell 24g ′.

  Because of this configuration, when a green component image as shown in FIG. 3 is acquired, the regularity of the alternating pattern in which light and dark are alternately arranged for each cell is adjacent to the first specific pattern 2. It is easy to specify the entire first boundary side 6a from the position to the position of the corner 5c.

  Further, the color reference pattern 24 includes a cell row 34 including cells adjacent to the second boundary side 6d (that is, cells 24g, 24f, and 24e in which a part of the outer edge is arranged at the position of the second boundary side 6d). ing. In this cell row 34, each cell 24g, 24f, 24e becomes three dark discrimination cells 24g ', 24f', 24e 'in the green component image shown in FIG. 3, and a dark continuous color pattern 34' in which only the dark discrimination cells are continuous. It is comprised so that. Therefore, the positions of the first boundary side 6b and the second boundary side 6d are accurately indicated by the alternating pattern 33 ′ and the dark continuous pattern 34 ′, respectively, and the corner position of the corner 5c is indicated by the dark discrimination cell 24g ′ at the top. Is more accurately shown, and the boundary in the vicinity of the corner 5c of the rectangular area can be specified more accurately during reading.

  The color reference pattern 25 having the same configuration as the color reference patterns 21 to 24 is also arranged at the diagonal position of the first specific pattern 2 in the code area (rectangular area) of the two-dimensional code 1. The color reference pattern 25 functions as an end pattern indicating the corner 5d of the code area (rectangular area), one outer edge is disposed along the second boundary side 6c, and is perpendicular to the one outer edge. The other outer edge is arranged along the second boundary side 6d, and the angular position of the corner 5d in the rectangular region is defined by these right-angled outer edges. In the present embodiment, the boundary sides that are not adjacent to the first specific pattern 2 are the second boundary sides 6c and 6d.

  The color reference pattern 25 includes a cell row 36 including cells adjacent to the second boundary side 6c (that is, cells 25c, 25d, and 25e in which part of the outer edge is disposed at the position of the second boundary side 6c). . The cell row 36 is configured to have an alternating pattern 36 ′ in which dark discrimination cells 25c ′ and 25e ′ are arranged at both ends and a light discrimination cell 25d ′ is arranged in the center in the green component image shown in FIG. Has been. In addition, the cell array 35 is formed of cells adjacent to the second boundary side 6d (that is, cells 25g, 25f, and 25e in which a part of the outer edge is disposed at the position of the second boundary side 6d). In this cell row 35, each of the cells 25g, 25f, and 25e becomes three dark discrimination cells 25g ', 25f', and 25e 'in the green component image shown in FIG. 3, and a dark color continuous pattern 35' in which only the dark discrimination cells are continuous. It is comprised so that.

  In the present embodiment, a first specific pattern 2 (reference pattern) serving as a position reference for the cell C in the rectangular area is provided at a prescribed corner 5a of the rectangular area. Since the first specific pattern 2 has annular and rectangular black cells arranged on the outer periphery, dark discrimination cells are arranged on the outer periphery in a rectangular shape in any color component image. Therefore, the background and the rectangular area can be distinguished using these dark discrimination cells.

  In addition, a plurality of color reference patterns 22, 24, and 25 are arranged at corners 5b, 5c, and 5d other than the prescribed corner 5a, and the color reference patterns 22, 24, and 25 are the color reference patterns. The corner cells arranged at the four corners are constituted by dark discrimination cells which are discriminated as dark in the green component image shown in FIG. That is, all the cells at the four corners of the color reference pattern 22 configured in a 3 × 3 matrix form are dark discrimination cells in the green component image, and the color having the same configuration as the color reference pattern 22 As for the reference patterns 24 and 25, all the cells at the four corners are dark discrimination cells in the green component image. Therefore, it is possible to dispose the dark discrimination cells at the corners 5b, 5c, and 5d in the green component image while making the color reference patterns 22, 24, and 25 all have the same color arrangement, and to accurately identify each corner. It becomes like this.

In addition, on the second boundary side 6c side and the second boundary side 6d side, color reference patterns 26 and 27 are provided at approximately the center positions of the respective boundary sides.
The color reference pattern 26 includes a cell row 37 including cells adjacent to the second boundary side 6c (that is, cells 26c, 26d, and 26e in which a part of the outer edge is disposed at the position of the second boundary side 6c). . The cell row 37 is configured to have an alternating pattern 37 ′ in which dark discrimination cells 26c ′ and 26e ′ are arranged at both ends and a light discrimination cell 26d ′ is arranged at the center in the green component image shown in FIG. Has been. The alternating pattern 37 ′ plays a role of specifying the second boundary side 6c together with the alternating patterns 39 ′ and 36 ′ adjacent to both ends of the second boundary side 6c.

  In addition, the color reference pattern 27 includes a cell row 35 including cells adjacent to the second boundary side 6d (that is, cells 27g, 27f, 27e in which a part of the outer edge is disposed at the position of the second boundary side 6d). ing. In this cell row 35, each cell 27g, 27f, 27e becomes three dark discrimination cells 27g ', 27f', 27e 'in the green component image shown in FIG. 3, and a dark continuous color pattern 38' in which only the dark discrimination cells are continuous. It is comprised so that. The dark color continuous pattern 38 'plays a role of specifying the second boundary side 6c together with the dark color continuous patterns 34' and 35 'adjacent to both ends of the second boundary side 6c.

  In the two-dimensional code 1 of FIG. 1, the same pattern 28 having the same configuration as the color reference patterns 21 to 27 is also arranged at a position away from the boundary of the rectangular area (the central position of the rectangular area in FIG. 1). . This same pattern 28 is also a pattern serving as a standard for the cell display color used for each cell in the rectangular area. Similar to the color reference patterns 21 to 27, all the cell display colors (black, White, red, green, blue, magenta, cyan, yellow). The same pattern 28 may be used as a predetermined reference position in the rectangular area. In this case, the same pattern 28 can function as an alignment pattern.

  Further, in the first specific pattern 2, cells of six colors other than the black cell and the white cell are arranged in the same manner as the arrangement of these six colors in the respective color reference patterns 21 to 27. According to this configuration, the first specific pattern 2 can be used as a color reference region.

  In the two-dimensional code 1 of the present embodiment, the first specific pattern 2 is arranged at the prescribed corner 5a of the code area (rectangular area), while the boundary side 6 of the code area (rectangular area) A part of the error correction code blocks 12 is arranged on the boundary side other than the side where the second specific patterns 3 and 4 are arranged (that is, on the second boundary sides 6c and 6d side). Yes. The error correction code block 12 on the second boundary side 6c side has a configuration in which at least one cell having a color, density, or luminance different from that of the background is arranged at a position adjacent to the second boundary side 6c. That is, it is known that the error correction code block 12 has a very low probability that cells of the same color as the background are continuously arranged due to the nature thereof. In this embodiment, such a property of the error correction code block 12 is known. At least one cell having a color, density, or luminance different from that of the background is arranged at a position adjacent to the second boundary side 6c. The same applies to the error correction code block 12 on the other second boundary side 6d side, and at least one cell (black cell) having a color, density or brightness different from that of the background is arranged at a position adjacent to the second boundary side 6d. It is configured to do. In the example of FIG. 1, the background is configured as white, and the error correction code block 12 is arranged so that at least one black cell or the like having a color different from the background is adjacent to the second boundary sides 2c and 2d. Therefore, the second boundary sides 2c and 2d can be specified with high accuracy using the black cell or the like as a mark.

Next, a reading process for reading the two-dimensional code 1 according to the present embodiment will be described.
The reading process is performed by an optical information reading apparatus including an image pickup unit that picks up a color image and an information processing unit.
As shown in FIG. 5, in the reading process, first, a process of acquiring image data of the two-dimensional code 1 is performed (S1). In this process, image data is acquired for each color component and stored in a memory. By this process, red component image data (R image data), green component image data (G image data), and blue component image data (B image data) are stored in the memory.

  Thereafter, bright and dark image data is calculated from the image data of each color component and stored in the memory (S2). In this process, a light / dark image in which a bright region and a dark region are distinguished from each other in the image data of each color component is generated and stored as data. Specifically, light / dark image data for the red component is acquired from the image data for the red component (R image data), and light / dark image data for the green component is acquired from the image data for the green component (G image data). Bright and dark image data for the blue component is acquired from the component image data (B image data) and stored in memory. The light and dark image of the green component for the two-dimensional code 1 of FIG. 1 has the structure shown in FIG. 3, and the data of such a light and dark image is stored in the memory in S2.

  After the process of S2, a process for specifying a two-dimensional code area is performed (S3). In the present embodiment, the two-dimensional code region is specified based on the green component light and dark image shown in FIG. Specifically, in the green component image shown in FIG. 3, the alternating pattern constituted by the specific pattern 2 ′ of the first specific pattern 2 and the second specific patterns 3 and 4, and the color reference patterns 22 and 24. , 25, 26, and 27, a pattern constituted by each cell row constituting the boundary portion of the rectangular region (the above-described alternating pattern or dark continuous pattern) is detected, and the boundary portion of the rectangular region is specified based on these patterns To do.

  Thereafter, the color reference pattern arranged in the two-dimensional code 1 is searched (S4). Then, a discrimination criterion for each color is set based on the retrieved color reference pattern (S5). As a method for setting a discrimination standard based on a color reference pattern, a method for setting a discrimination standard based on any one of the color reference patterns may be used. The discrimination standard is set based on a plurality of color reference patterns. It may be a method to do. Hereinafter, as an example, an example in which a discrimination criterion is set based on the color reference pattern 21 will be described.

  Each cell of the color reference pattern 21 is handled as a standard color of each color, and is used to set a threshold value for determining which color each cell constituting the two-dimensional code 1 corresponds to. . Specifically, a threshold for determining each black cell of the two-dimensional code 1 is set based on at least the black cell 21a or 21e, and a threshold for determining each red cell of the two-dimensional code 1 is at least a red cell. The threshold for determining each green cell of the two-dimensional code 1 is set based on at least the green cell 21d, and the threshold for determining each blue cell of the two-dimensional code 1 is at least a blue cell. It is set based on 21g. Further, a threshold value for determining each cyan cell of the two-dimensional code 1 is set based on at least the cyan cell 21b, and a threshold value for determining each magenta cell of the two-dimensional code 1 is at least the magenta cell 21f. Is set based on at least the yellow cell 21h, and the threshold for determining each white cell of the two-dimensional code 1 is set to the white cell 21i. It is set based on.

  The threshold setting process can be performed as follows, for example. First, when converting image data acquired by the light receiving sensor from an analog signal to a digital signal, it is necessary to determine each of the RGB signals. For example, in an R image (an image composed of R components), there is no significant difference in signal levels obtained from each color of “red”, “white”, “magenta”, and “yellow”. It becomes a level similar to “Ming”. On the other hand, in the R image, there is no significant difference in the signal levels obtained from the colors of “black”, “green”, “blue”, and “cyan”, and in the R image, these are all levels similar to “dark”. This tendency is that the signal level obtained from each color of “green”, “white”, “cyan”, “yellow” becomes “bright” level in the G image (image composed of G components), and “black”, “red” ”,“ Blue ”, and“ magenta ”, the signal level obtained from each color becomes the“ dark ”level. Similarly, in the B image (image composed of the B component), the signal level obtained from each color of “blue”, “white”, “cyan”, and “magenta” becomes the “bright” level, and “black” “red” “ The signal level obtained from each color of “green” and “yellow” becomes the “dark” level.

  Accordingly, when all of the R image, G image, and B image are “bright”, it is determined as “white”, and when all of the R image, G image, and B image are “dark”, “black” is determined. Determined. Also, it is determined as “red” when the image is “bright” only when the image is R, and “red” when it is “dark” when the image is B, and only when it is “bright” when the image is G image. When it is “dark”, it is determined as “green”, and when it is B image, it is determined as “bright” when it is “bright” and R image, and when it is “dark” when it is G image.

  Also, if the image is “bright” for the G image and B image and “dark” for the R image, it can be determined as “cyan”, and “bright” can be determined for the R image and B image. When the image is “dark”, it can be determined as “magenta”, and when the image is R or G, it is “bright”, and when it is “B”, it is “yellow”. Can be determined.

  Since each color can be determined as described above, by setting threshold values for determining light and dark for each of the R image, G image, and B image, the cell colors constituting the two-dimensional code 1 are determined based on the image data. The determination can be made with certainty.

  A setting method for setting a threshold value for distinguishing light and darkness in the R image, a threshold value for distinguishing light and darkness in the G image, and a threshold value for distinguishing light and darkness in the B image based on the color reference pattern searched in S4 For example, when the color reference pattern 21 is used as a determination criterion, the threshold value of the R image includes a red cell 21d, a magenta cell 21f, a white cell 21i, and a yellow cell in the R image of the two-dimensional code 1. The average value of the brightness level of the cell 21h and the average value of the brightness levels of the blue cell 21g, the green cell 21d, the black cells 21a and 21e, and the cyan cell 21b are calculated. For example, a threshold value may be used. In this case, the threshold values for the G image and the B image can be set as in the case of the R image. Note that the threshold setting method is merely an example, and it goes without saying that another method may be used as long as it can be set using a color reference pattern as shown in FIGS.

  After the process of S5, the color of each cell in the data area is specified based on the threshold set in S5 (S6), and the decoding process is performed based on the specified result (S7). Then, the decoding result is output (S8).

According to the configuration of the present embodiment, for example, the following effects can be obtained.
In the two-dimensional code 1 of the present embodiment, since the color reference patterns 21 to 27 serving as the standard of the cell display color used for each cell in the rectangular area are provided, the color of each cell is highly accurate at the time of reading. Easy to judge. Furthermore, since the cell row of the color reference patterns 21 to 27 is configured as a boundary portion of the rectangular area, and is configured with a predetermined color arrangement for separating the rectangular area and the background, the code area and the background are highly accurate. The structure which can be separated can be realized more efficiently.

  In addition, since the color reference patterns 21 to 27 are configured in a matrix of 3 rows and 3 columns, the color reference patterns are configured in a compact manner, and the cell columns for separating from the background are appropriately configured using 3 cells. it can.

  The second specific patterns 3 and 4 for separating the rectangular area and the background are arranged along the boundary of the rectangular area, and the cell rows 30 and 31 of the color reference patterns 21 and 22 are the second specific patterns. It is configured as a part of the pattern 3. Further, the cell rows 32 and 3 of the color reference patterns 23 and 24 are configured as a part of the second specific pattern 4. In this way, not only the color reference patterns 21, 22, 23, 24, but also the rectangular regions using other parts (parts other than the color reference patterns 21, 22, 23, 24) in the second specific patterns 3, 4. Can be separated from the background, and can be separated with higher accuracy and better.

  Further, when a rectangular region is imaged and an image of a predetermined color component is acquired, portions (alternate patterns 30 ′, 31 ′) constituted by the cell rows 30, 31 in the image and the cell rows 30, 31 are obtained. The parts (alternate patterns 3a ′, 3b ′) constituted by other parts other than are configured to be a continuous specific pattern. Further, in the image, the portion constituted by the cell rows 32 and 33 (alternate patterns 32 ′ and 33 ′) and the portion constituted by other portions other than the cell rows 32 and 33 (alternate patterns 4a ′ and 4b ′). Are configured to be a continuous specific pattern. In this way, a specific pattern that can specify the boundary of the rectangular area when an image of a predetermined color component is acquired is configured, and the rectangular area can be separated with higher accuracy based on the specific pattern. In particular, the specific pattern is not constituted only by the color reference pattern or only by the other part other than the color reference pattern, but the specific pattern is constituted by continuing these, so that the color reference pattern can be arranged efficiently. A specific pattern can be provided longer.

  In addition, other parts of the second specific pattern 3 (parts other than the cell rows 30 and 31 forming part of the color reference patterns 21 and 22, that is, the black and white alternating patterns 3 a and 3 b) are included in the image of a predetermined color component. The light discrimination cells discriminated as bright and the dark discrimination cells discriminated as dark are arranged in an alternating pattern 3a ′, 3b ′. In this way, it becomes easy to specify the rectangular area with high accuracy while suppressing the influence of the background color. In particular, in an image of a predetermined color component, the cell rows 30 and 31 that form part of the color reference patterns 21 and 22 and other portions (black and white alternating patterns 3a and 3b) other than the cell rows 30 and 31 are consecutively alternated. Since the pattern is configured to be a pattern, the alternating pattern can be expressed in a wider area while arranging the color reference patterns 21 and 22 at the boundary, and the rectangular area can be separated with higher accuracy. Such an effect is the same in the second specific pattern 4.

  In addition, since the first specific pattern 2 (reference pattern) serving as a reference for the position of the cell in the rectangular area is provided at the predetermined corner 5a of the rectangular area, the first corner 5a is defined as the first specific pattern 2 (reference pattern). The specific pattern 2 can be specified with high accuracy. On the other hand, since the color reference patterns 22, 24 and 25 are arranged for the corners 5b to 5d other than the prescribed corner 5a, the color reference patterns 22, 24 and 25 are used for the corners 5b to 5d. It becomes possible to identify. Further, the corner cells of each color reference pattern 22, 24, 25 (respective cells arranged at the four corners of each color reference pattern 22, 24, 25) are dark discrimination cells (dark images in a predetermined color component image). In the image of the predetermined color component, dark colors are arranged at the corners 5b to 5d of the rectangular area, and the background color is light in the color component image. Sometimes, the corners 5b to 5d can be specified more accurately.

  In addition, since a plurality of color reference patterns are provided in the same color arrangement, the cell display color standard can be obtained using any of the plurality of color reference patterns 21 to 27. This is advantageous when reading is difficult. Further, since the plurality of color reference patterns 21 to 27 are configured in the same color arrangement, it is not necessary to use a complicated reading method or reading information for reading each pattern (for example, each color reference pattern 21 to 27). It is not necessary to set a unique reading method for each), and the reading can be simplified.

[Second Embodiment]
Next, a second embodiment will be described. FIG. 6 is an explanatory diagram schematically illustrating a two-dimensional code according to the second embodiment. FIG. 7A is an explanatory diagram for explaining a color reference pattern used in the two-dimensional code of FIG. 6, and FIG. 7B schematically shows a light / dark configuration of the color reference pattern when a green component image is acquired. It is explanatory drawing demonstrated. FIG. 8 is an explanatory diagram schematically illustrating a light / dark configuration when a green component image is acquired for the two-dimensional code of FIG. 6.

  The two-dimensional code 200 of the present embodiment is different from the two-dimensional code 1 of the first embodiment in the configuration of the first specific pattern 202, the second specific patterns 203 and 204, and the color reference patterns 221 to 228. The same as the two-dimensional code 1 of the first embodiment. For example, since the configuration in the data recording area AR is the same as that of the two-dimensional code 1 of the first embodiment, detailed description of the data code block 11 and the error correction code block 12 is omitted.

  The two-dimensional code 200 of the present embodiment is also configured so that a plurality of cells C are two-dimensionally arranged in a rectangular area, and the information encoded by the color, density, or luminance of each cell C is expressed in color. ing.

  Further, the two-dimensional code 200 of the present embodiment is also provided with color reference patterns 221 to 227 serving as a standard of cell display colors used for each cell C in the rectangular area. As shown in FIGS. 6 and 7A, each of the color reference patterns 221 to 227 is formed by arranging a plurality of cells in a 3 × 3 matrix, and the color reference patterns 221 to 227. In both cases, a part of the cell rows is configured as a boundary portion of the rectangular area. The color reference patterns 221 to 227 are configured to display all cell display colors (black, white, red, green, blue, magenta, cyan, yellow) used in the two-dimensional code 200. . In FIG. 7A, only the color reference pattern 221 is shown in an enlarged manner. However, since the color reference patterns 222 to 227 have the same configuration as the color reference pattern 221, the color reference patterns 222 to 227 are the same. The enlarged view of is omitted.

  The two-dimensional code 200 is provided with a first specific pattern 202 (reference pattern) that serves as a position reference of the cell C in the rectangular area at a specified corner 5c of the rectangular area. Second specific patterns 203 and 204 are arranged along first boundary sides 6 a and 6 b adjacent to 202. The first specific pattern 202 is the same as the first specific pattern 2 of the first embodiment in that the black cell is arranged at the center and the black cell is arranged in an annular and rectangular shape on the outermost periphery. Yes, only the arrangement of cells of six colors other than black and white arranged inside is different from the first specific pattern 2 of the first embodiment.

  The second specific pattern 203 corresponds to an example of a “specific pattern” and has a function of separating a rectangular area and a background. The second specific pattern 203 is disposed adjacent to the first boundary side 6a serving as the boundary of the rectangular region, and includes cell rows 230 and 231 that form part of the color reference patterns 221 and 222, and black It is constituted by black continuous patterns 203a and 203b in which cells are continuous.

  Also in this embodiment, when a rectangular region is imaged and a green component image is acquired, the image includes a portion constituted by the cell rows 230 and 231 and a portion other than the cell rows 230 and 231 in the image. The portion to be formed is configured to be a continuous specific pattern.

  More specifically, the black continuous pattern 203a corresponds to “another portion”, and is configured to be a dark continuous color pattern 203a ′ in which dark discrimination cells are continuous in the green component image shown in FIG. . Further, the cells 221a, 221b, and 221c constituting the cell row 230 of the color reference pattern 221 are configured as dark discrimination cells 221a ′, 221b ′, and 221c ′ in the green component image, respectively. That is, as shown in FIG. 7A, each of the cells 221a, 221b, and 221c is composed of a black cell, a magenta cell, and a red cell that are determined to be dark in the green component image. The image is configured as a dark continuous pattern 230 ′ as shown in FIG. 7B. The dark color pattern 230 ′ is continuous with the dark color continuous pattern 203a ′ in the image.

  Further, the black continuous pattern 203b adjacent to the cell row 230 is also configured to be a dark continuous pattern 203b ′ in which the dark discrimination cells are continuous in the green component image shown in FIG. Further, the cells 222a, 222b, and 222c constituting the cell row 231 of the color reference pattern 222 are configured as dark discrimination cells 222a ′, 222b ′, and 222c ′ in the green component image, respectively, and the dark continuous color pattern 203b ′. It is comprised so that it may become the continuous dark color continuous pattern 231 '.

  That is, the second specific pattern 203 includes a dark continuous color pattern 203a ′ by the black continuous pattern 203a, a dark continuous color pattern 230 ′ by the cell row 230, a dark continuous color pattern 203b ′ by the black pattern 203b, and a cell row 231 in the green component image. The continuous dark color pattern 231 ′ is continuously formed, and is configured by dark discrimination cells from the position adjacent to the first specific pattern 2 to the position of the corner 5b.

  The second specific pattern 204 also corresponds to an example of a “specific pattern” and has a function of separating a rectangular area and a background. The second specific pattern 204 is disposed adjacent to the first boundary side 6b serving as the boundary of the rectangular region, and the cell row 232 at the boundary portion of the color reference pattern 223 and the boundary portion of the color reference pattern 224 are arranged. The cell array 233 includes black and white alternating patterns 4a and 4b in which white cells and black cells are alternately arranged. The black and white alternating patterns 4a and 4b have the same configuration as the two-dimensional code 1 of the first embodiment. The second specific pattern 204 also includes portions (alternate patterns 232 ′ and 233 ′) constituted by the cell rows 232 and 233 and a black and white alternating pattern other than the cell rows 232 and 233 in the green component image shown in FIG. The parts (alternate patterns 4a ′, 4b ′) constituted by 4a, 4b (other parts) are configured to be a continuous specific pattern. The specific pattern of the second specific pattern 204 is substantially the same as the specific pattern (alternate pattern) of the second specific pattern 4 of the first embodiment, and a detailed description thereof will be omitted.

  Note that also in the two-dimensional code 200 of the present embodiment, a plurality of color reference patterns 222, 224, and 225 are respectively arranged at corners 5b, 5c, and 5d other than the prescribed corner 5a, and these color reference patterns. 222, 224, and 225 are constituted by dark discrimination cells in which the corner cells arranged at the four corners are determined to be dark in the green component image shown in FIG. For example, the color reference pattern 222 is configured such that any of the cells at the four corners is a dark discrimination cell in the green component image shown in FIG. 8, and the color reference having the same configuration as the color reference pattern 222 is configured. The same applies to the patterns 224 and 225, and any of the cells at the four corners is configured to be a dark discrimination cell in the green component image.

  In addition, on the second boundary side 6c side and the second boundary side 6d side, color reference patterns 226 and 227 are respectively provided at substantially center positions of the respective boundary sides. In addition, the same pattern 228 having the same configuration as the color reference patterns 221 to 227 is also arranged at a position away from the boundary of the rectangular area (the central position of the rectangular area in FIG. 6). This same pattern 228 is also a standard pattern of cell display colors used for each cell in the rectangular area. Similar to the color reference patterns 221 to 227, all cell display colors (black, White, red, green, blue, magenta, cyan, yellow).

  In the configuration of this embodiment, the black continuous patterns 203a and 203b (other portions) of the second specific pattern 203 become dark continuous patterns 203a ′ and 203b ′ in which dark discrimination cells are continuous in an image of a predetermined color component. It is configured as follows. In this way, it becomes easier to specify the boundary of the rectangular area more clearly when the background color is light in the image of the color component. In addition, in an image of a predetermined color component, a portion (dark continuous pattern 230 ′, 231 ′) constituted by cell rows 230, 231 forming a part of the color reference pattern 221 and a portion other than the cell row (that is, black) Since the dark continuous pattern is formed continuously with the portions (dark continuous patterns 203a ′ and 203b ′) configured by the continuous patterns 203a and 203b), the dark color is provided while arranging the color reference patterns 221 and 222 at the boundary portions. A continuous pattern can be expressed in a wider area, and rectangular areas can be separated with higher accuracy.

[Third Embodiment]
Next, a third embodiment will be described. FIG. 9 is an explanatory diagram schematically illustrating a two-dimensional code according to the third embodiment. FIG. 10 is an explanatory diagram schematically illustrating a light / dark configuration when a green component image is acquired for the two-dimensional code of FIG. 9.

  The two-dimensional code 300 of this embodiment is different from the two-dimensional code 1 of the first embodiment in the configuration of the first specific pattern 302, the second specific patterns 303 and 304, and the color reference patterns 321 to 328. The same as the two-dimensional code 1 of the first embodiment. For example, since the configuration in the data recording area AR is the same as that of the two-dimensional code 1 of the first embodiment, detailed description of the data code block 11 and the error correction code block 12 is omitted.

  The two-dimensional code 300 of the present embodiment is also configured so that a plurality of cells C are two-dimensionally arranged in a rectangular area, and the information encoded by the color, density, or luminance of each cell C is expressed in color. ing.

  In addition, the two-dimensional code 300 of the present embodiment is also provided with color reference patterns 321 to 227 serving as the standard of the cell display color used for each cell C in the rectangular area. As shown in FIG. 9, all of the color reference patterns 321 to 327 are formed by arranging a plurality of cells in a 3 × 3 matrix, and all of the color reference patterns 321 to 327 are partly. Are arranged as a boundary portion of the rectangular area. The color reference patterns 321 to 327 are configured to display all cell display colors (black, white, red, green, blue, magenta, cyan, yellow) used in the two-dimensional code 300. . In the example of FIG. 9, all the color reference patterns 221 to 227 have the same configuration.

  The two-dimensional code 300 is provided with a first specific pattern 302 (reference pattern) serving as a position reference of the cell C in the rectangular area at a specified corner 5c of the rectangular area. Second specific patterns 303 and 304 are arranged along first boundary sides 6 a and 6 b adjacent to 302. The first specific pattern 302 is the same as the first specific pattern 2 of the first embodiment in that the black cell is arranged in the center and the black cells are arranged in an annular and rectangular shape on the outermost periphery. Yes, only the arrangement of cells of six colors other than black and white arranged inside is different from the first specific pattern 2 of the first embodiment.

  The second specific pattern 303 is adjacent to the end of the first specific pattern 302, and is adjacent to the first boundary side 6a over the entire region from the adjacent position to the corner 5b. Part of the second specific pattern 3 is configured by color reference patterns 321 and 322, and the other part other than the color reference patterns 321 and 322 is configured by black and white alternating patterns 303a and 303b including white cells and black cells. Has been.

  The black-and-white alternating pattern 303 a arranged between the first specific pattern 2 and the color reference pattern 321 has a black cell adjacent to the first specific pattern 302 as one end and a white cell adjacent to the color reference pattern 21. It is composed of 11 cells as the other end, and is arranged in a line along the first boundary side 6a. In this black-and-white alternating pattern 303a, black cells are arranged adjacent to black cells at one end (black cells adjacent to the first specific pattern 2) (that is, two black cells are continuous), and then white cells are Two white cells and two black cells are alternately arranged in such a form that two are continuously arranged.

  The same applies to the black-and-white alternating pattern 303b arranged between the two-color reference patterns 321 and 322. The white cell adjacent to the color reference pattern 321 is one end and the black cell adjacent to the color reference pattern 322 is the other end. It is composed of 11 cells as a part, and is arranged in a line along the first boundary side 6a. Also in this black and white alternating pattern 303b, white cells are arranged adjacent to the white cells at one end (white cells adjacent to the color reference pattern 21) (that is, two white cells are continuous), and then the black cells are 2 Two white cells and two black cells are alternately arranged in such a form that they are continuously arranged.

  In addition, the color reference pattern 321 is disposed adjacent to a substantially central position of the first boundary side 6a, and a cell adjacent to the first boundary side 6a (that is, a part of the outer edge is a position of the first boundary side 6a). A cell row 330 composed of cells 321a, 321b, 321c) arranged in a rectangular area is configured as a boundary portion of the rectangular area. A cell column 330 including these cells 321a, 321b, and 321c is configured with a predetermined color arrangement (described later) for separating the rectangular area and the background of the rectangular area, and a part of the second specific pattern 303. The one end side is adjacent to the black-and-white alternating pattern 303a and the other end side is adjacent to the black-and-white alternating pattern 303b.

  The color reference pattern 322 is arranged adjacent to the end of the first boundary side 6a, and a cell adjacent to the first boundary side 6a (that is, a part of the outer edge is arranged at the position of the first boundary side 6a). The cell row 331 including the cells 322a, 322b, and 322c) is configured with a predetermined color arrangement (described later) for separating the rectangular area and the background of the rectangular area. The cell row 331 is configured as a part of the second specific pattern 303, and one end side is adjacent to the black and white alternating pattern 303b, and the other end portion is configured as a corner 5b of a rectangular area. The color reference pattern 322 has a function as an end pattern indicating the end of the first boundary side 6a.

  In the second specific pattern 303 configured in this manner, in the green component image shown in FIG. 10, the light and dark pattern 330 ′ of the cell row 330 is continuous with the alternating pattern 303a ′ of the black and white alternating pattern 303a. The light and dark pattern 330 ′ is continuous with the alternating pattern 303 b ′ of the black and white alternating pattern 303 b, and further, the light and dark pattern 331 ′ of the cell row 331 is continuous with the alternating pattern 303 b ′ and is adjacent to the first specific pattern 302. In the region from the position to the corner 5b, an alternating pattern is formed in which bright discrimination cells that are continuous every two cells and dark discrimination cells that are continuous every two cells are alternately arranged.

  The configuration of the other second specific pattern 304 is the same. The black and white alternating pattern 304a, the cell row adjacent to the first boundary 6b in the color reference pattern 323, the black and white alternating pattern 304b, and the first in the color reference pattern 324 are the same. In the green component image shown in FIG. 10, an alternating pattern 304 a ′, a light / dark pattern 332 ′, an alternating pattern 304 b ′, and a light / dark pattern 333 ′ are formed by the cell row adjacent to the boundary portion 6 b, and the first specific pattern 302 In the region from the adjacent position to the corner 5c, an alternating pattern is formed in which bright discrimination cells that are continuous by two cells and dark discrimination cells that are continuous by two cells are alternately arranged.

[Other Embodiments]
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.

  In the above embodiment, the configuration in which other portions other than the first specific pattern and the color reference pattern exist in the first boundary portion is illustrated, but a configuration in which such other portions do not exist may be employed. For example, any or all of the black-and-white alternating patterns 3a, 3b, 4a, and 4b in FIG. 1 may be omitted, and the error correction code block 12 and the data code block 11 may be disposed at that position. Alternatively, the black continuous patterns 203a and 203b and the black and white alternating patterns 4a and 4b may be omitted in the configuration of FIG. 6, and the error correction code block 12 and the data code block 11 may be arranged at the positions.

  In the above-described embodiment, the “green component image” is exemplified as the “predetermined color component image”, but a red component image or a blue component image may be used. For example, if all of the color reference patterns 21 to 28 in FIG. 1 are changed to the patterns as shown in FIG. 11, when the red component image is acquired, the same light / dark configuration as in FIG. 3 is obtained (see also FIG. 4A). The same effect as the first embodiment can be obtained. Further, if all the color reference patterns 21 to 28 in FIG. 1 are changed to the patterns as shown in FIG. 12, when a blue component image is acquired, the same light / dark configuration as in FIG. 3 is obtained (see also FIG. 4C). The same effect as the first embodiment can be obtained.

  In the above-described embodiment, an example in which the color reference pattern is configured by cells of eight colors has been described. However, the color reference pattern may be configured by a larger number of colors or a smaller number of colors. For example, FIG. 13A shows an example in which a color reference pattern is configured by cells of five colors (black, white, cyan, magenta, and yellow). Since the light and dark pattern as shown in FIG. 13B is obtained in the component image, even if all the color reference patterns 21 to 28 in FIG. 1 are changed to the color reference patterns as shown in FIG. Bright and dark array data is obtained, and the same effect as in the first embodiment is obtained. FIG. 14A shows an example in which a color reference pattern is configured by cells of four colors (black, cyan, magenta, and yellow). When such a color reference pattern is used, an image of a green component is shown. 14B, the light / dark pattern as shown in FIG. 3 is obtained even if all the color reference patterns 21 to 28 shown in FIG. 1 are changed to the color reference patterns shown in FIG. 14A. And the same effect as in the first embodiment can be obtained.

  In the above embodiment, an example in which the color reference pattern is configured in a matrix of 3 rows and 3 columns has been described, but a different matrix configuration may be used. For example, a 4 × 4 matrix configuration may be used. With such a configuration, the color reference pattern can be configured by cells of eight colors or more (for example, cells of 16 colors).

  In the above-described embodiment, the example in which the error correction code block 12 is arranged adjacent to the boundary side of the rectangular area has been described. However, the compressed data so as to be adjacent to one or both of the second boundary sides 6c and 6d. A compressed data code block may be arranged. This compressed data code block is a block of compressed data obtained by compressing data to be encoded using a known compression method. The compression algorithm is a known compression algorithm such as run-length coding or Huffman coding. Any of them may be used. For example, in the case of using run-length encoding, when information to be decoded is information “0000000000000001111”, 12 0s (1100 in binary number) and 4 1s (0100 in binary number) are arranged. It can be expressed as “0110010100” in which “0”, “1100”, “1”, and “0100” are arranged, and the number of numbers can be reduced. As a result, it is possible to suppress a long continuous cell having the same color as the background color in the compressed data code block. For example, when the background color is white or a color close to this and the white cell indicates “0”, it becomes difficult for white cells close to the background color to continue at the boundary of the rectangular region, and the rectangular region and the background are distinguished. It becomes easy.

FIG. 1 is an explanatory diagram schematically illustrating a two-dimensional code according to the first embodiment. FIG. 2A is an explanatory diagram for explaining a color reference pattern used in the two-dimensional code of FIG. 1, and FIG. 2B schematically shows a light / dark configuration of the color reference pattern when a green component image is acquired. It is explanatory drawing demonstrated. FIG. 3 is an explanatory diagram schematically illustrating a light / dark configuration when a green component image is acquired for the two-dimensional code of FIG. 1. FIG. 4A is an explanatory diagram for explaining the relationship between each color and brightness in the red component image, and FIG. 4B is an explanatory diagram for explaining the relationship between each color and brightness in the green component image. () Is an explanatory diagram for explaining the relationship between each color and brightness in a blue component image. FIG. 5 is a flowchart illustrating a reading process for reading the two-dimensional code of this embodiment. FIG. 6 is an explanatory diagram schematically illustrating a two-dimensional code according to the second embodiment. FIG. 7A is an explanatory diagram for explaining a color reference pattern used in the two-dimensional code of FIG. 6, and FIG. 7B schematically shows a light / dark configuration of the color reference pattern when a green component image is acquired. It is explanatory drawing demonstrated. FIG. 8 is an explanatory diagram schematically illustrating a light / dark configuration when a green component image is acquired for the two-dimensional code of FIG. 6. FIG. 9 is an explanatory diagram schematically illustrating a two-dimensional code according to the third embodiment. FIG. 10 is an explanatory diagram schematically illustrating a light / dark configuration when a green component image is acquired for the two-dimensional code of FIG. 9. FIG. 11 shows another example 1 of the color reference pattern, and is an explanatory diagram for explaining a configuration that functions effectively in a red component image. FIG. 12 illustrates another example 2 of the color reference pattern, and is an explanatory diagram illustrating a configuration that functions effectively in a blue component image. FIG. 13A illustrates another example 3 of the color reference pattern, and is an explanatory diagram illustrating an example configured by cells of five colors. FIG. 13B is an explanatory diagram illustrating a light / dark pattern in the green component image for the color reference pattern of FIG. FIG. 14A illustrates another example 4 of the color reference pattern, and is an explanatory diagram illustrating an example configured by cells of four colors. FIG. 14B is an explanatory diagram illustrating a light / dark pattern in the green component image for the color reference pattern of FIG.

Explanation of symbols

1, 200, 300 ... two-dimensional code 2, 202, 302 ... first specific pattern (reference pattern)
3, 4, 203, 204, 303, 304 ... second specific pattern (specific pattern)
3a, 3b, 4a, 4b, 303a, 303b, 304a, 304b ... black and white alternating pattern (other parts)
21-27, 221-227, 321-327 ... color reference pattern 203a, 203b ... black continuous pattern (other parts)
C ... cell

Claims (10)

A two-dimensional code in which a plurality of cells are two-dimensionally arranged in a rectangular region, and the information encoded by the color, density, or luminance of each cell is expressed in color,
A color reference pattern serving as a standard of the cell display color used for each cell in the rectangular area;
The color reference pattern is
A plurality of cells are arranged in a matrix, and at least some of the cell rows are configured as boundaries of the rectangular region,
Further, the two-dimensional code characterized in that the cell string configured as a boundary portion of the rectangular area is configured with a predetermined color arrangement for separating the rectangular area and the background of the rectangular area.   The two-dimensional code according to claim 1, wherein the color reference pattern is configured in a matrix of 3 rows and 3 columns. A specific pattern for separating the rectangular area and the background is disposed along a boundary of the rectangular area;
The two-dimensional code according to claim 1 or 2, wherein the cell string of the color reference pattern is configured as a part of the specific pattern.   When the rectangular pattern is captured and an image of a predetermined color component is acquired, the specific pattern is a portion configured by the cell row and a portion other than the cell row in the image. The two-dimensional code according to claim 3, wherein the two-dimensional code is configured to have a continuous specific pattern. The other part of the specific pattern is an alternating pattern in which the light determination cells determined to be light and the dark determination cells determined to be dark are alternately arranged in the image of the predetermined color component. Configured,
5. The two-dimensional code according to claim 4, wherein the cell row is configured to have an alternating pattern continuous with the alternating pattern of the other portion in the image of the predetermined color component. The other portion of the specific pattern is configured to be a dark continuous color pattern in which dark determination cells determined to be dark are continuous in the image of the predetermined color component,
5. The two-dimensional code according to claim 4, wherein the cell row is configured to be a dark continuous pattern that is continuous with the dark continuous pattern of the other portion in the image of the predetermined color component.   The color reference pattern is configured as a dark discrimination cell in which at least the cells at both ends of the cell row are determined to be dark in the image when the rectangular area is captured and an image of a predetermined color component is acquired. The two-dimensional code according to claim 1 or 2, characterized in that   8. The two-dimensional code according to claim 7, wherein in the color reference pattern, all cells constituting the cell row are configured as the dark discrimination cells. A reference pattern serving as a position reference of the cell in the rectangular area is provided at a predetermined corner of the rectangular area.
A plurality of the color reference patterns are respectively arranged at corners other than the prescribed corners;
The color reference pattern is configured such that corner cells arranged at four corners of the color reference pattern are dark discrimination cells that are determined to be dark in the image of the predetermined color component. The two-dimensional code according to any one of claims 4 to 8.   The two-dimensional code according to any one of claims 1 to 9, wherein a plurality of the color reference patterns are provided in the rectangular area in the same color arrangement.

Images