JP2003076962A - Two-dimensional code, read method for two-dimensional code, program and computer readable recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a two-dimensional code of a large capacity and a small size capable of securing sufficient positioning accuracy, the read method, a program and a computer readable recording medium. SOLUTION: Around a data part 2, a first graphic provided with line segments LS11-LS14, LS31-LS34, LS51-LS54 and LS71-LS74 arranged at a pitch corresponding to the size of a small area and header lines R21-R24, R41-R44, R61-R64 and R81-R84 respectively vertically extended from the almost center part of the line segments and an L-shaped second graphic LC whose both ends are continued to end parts of the LS54 and the LS74 are arranged. The header lines R21-R24 and R41-R44 are arranged to the outer side of the data part 2 and the header lines R61-R64 and R81-R84 are arranged to the data part 2. On the basis of the header lines, information of a data density and positioning information are acquired at the time of decoding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-dimensional code and a method for reading the same, and more particularly to a two-dimensional code for improving data density, a method for reading the same, a program for causing a computer to execute the reading method, and a computer reading method. It relates to a possible recording medium.

[0002]

2. Description of the Related Art Since a two-dimensional code can encode a plurality of types of characters and has an error correction function, it has been used in fields such as distribution and product management, and various types of two-dimensional codes have been developed. Came.

The conventional two-dimensional code is used only as an alternative to the one-dimensional bar code, and therefore, for example, a management code and information accompanying it,
The required specifications were sufficient if a small amount of information could be stored.

In recent years, there has been an increasing momentum to support the independence of various people with disabilities and actively promote social participation. In such a movement, the inventor of the present application examined the use of the two-dimensional code in developing the text-to-speech device for the visually impaired. From the point of view of practicality, it is required that the information of one page of text, specifically, about 800 characters in Japanese can be stored as a symbol of 2 cm ² and can be printed by a commercially available laser printer. .

[0005]

However, if the above-mentioned required specifications are to be realized by the conventional two-dimensional code,
If printing is performed at a desired density, a sufficient reading rate cannot be obtained. On the other hand, if printing is performed at a readable density, the size becomes too large.

One of the causes of such a problem is as follows.
Since the conventional two-dimensional code is not designed to store the above-mentioned large amount of information, increasing the capacity increases the overhead of the print area other than the data cells.

A problem with the read rate is that the positioning accuracy cannot be sufficiently ensured when sampling the data cells. Conventionally, as one method of indicating the print pitch of the data cell, a bright / dark figure having the same size as the data cell is used.
There have also been attempts to arrange cells alternately. However, with this method, it has been difficult to improve the accuracy due to the characteristics peculiar to the printer, such as toner particles being scattered or faint when printing is performed at high density with the current laser printer.
On the other hand, it has been found that if the positioning can be performed with sufficient accuracy, the data reading can be sufficiently combined by image processing or error correction code processing even if there is some toner scattering or blurring in printing.

The present invention has been made in view of the above circumstances, and an object thereof is to print with a general-purpose laser printer,
It is to provide a large-capacity and small-size two-dimensional code capable of ensuring sufficient positioning accuracy, a reading method thereof, a program, and a computer-readable recording medium.

[0009]

The present invention solves the above problems by the following means.

That is, according to the present invention, a bit of the binarized data is symbolized as a square data cell of a bright portion or a dark portion and arranged so as to form a two-dimensional matrix; A two-dimensional arrangement including a first figure which is arranged in a peripheral part and which gives information on a printing pitch of the cell, and a second figure which is arranged in a peripheral part of the data part and gives information on a rotation direction of the cell. Code,
In the data section, a small square region in which the N data cells are arranged adjacent to each other in the first and second directions orthogonal to each other (N is a natural number) is L in the first direction. L is a natural number), and M pieces (M is a natural number) are arranged adjacent to each other in the above-mentioned 2 direction, and the shape of the peripheral edge of the data part is the first side in the above-mentioned second direction. It is a rectangle having a second side orthogonal to the first side and third and fourth sides orthogonal to each other and facing the first and second sides, respectively, and the first figure is It is arranged close to the data part along the first side, and is spaced apart from each other at a pitch according to the size of the small area, starting from the vicinity of the intersection of the first side and the second side. And (M + 1) first line segments arranged in the same direction and the first direction and the data It provided so as to protrude from approximately the center of the first line segment toward outward (M +
1) The number of the second line segment and the size of the small area, which are arranged close to the data section along the second side and whose origin is the vertex of the first second line segment. (L + 1) third line segments that are spaced apart from each other at a pitch according to, and from the center of the second line segment in the second direction toward the outside of the data section. The (L + 1) fourth line segments provided so as to respectively project, and the vertices of the fourth line segments which are arranged apart from the data part along a line parallel to the third side. (M + 1) fifth line segments which are spaced apart from each other at a pitch according to the size of the small area, starting from one point on the line connecting the line and the corresponding extended line of the second line segment, respectively. It is arranged so as to extend from substantially the center of the fifth line segment toward the data section (M 1) Sixth line segments and a line parallel to the fourth side are spaced apart from the data part, and one point on the line connecting the vertices of the second line segment is used as a starting point. The (L + 1) seventh line segments are arranged at a pitch according to the size of the small regions and are spaced apart from each other, and are arranged on the corresponding extended line of the fourth line segment.
And an eighth line segment provided so as to project from substantially the center of the line segment toward the data portion, the second figure has the (M + 1) th fifth segment at both ends thereof. The line segment is an L-shaped figure provided so as to be continuous with the (L + 1) th seventh line segment, and the fifth line segment and the seventh line segment are the sixth line segment. A two-dimensional code is provided, wherein the apex and the eighth line segment are spaced apart from the data part such that they are spaced from the third side and the fourth side, respectively.

Further, according to the present invention, there is provided the above-described method for reading a two-dimensional code according to the present invention, wherein a procedure for obtaining an image of the two-dimensional code and a periphery of the obtained image are the above-mentioned edges. While contacting the corner portion of the second figure, at least a part of the first line segment and the first line segment
A procedure of cutting out a rectangular area surrounding the pattern so as to include at least a part of the seventh seventh line segment, a contact point with the corner portion, the first seventh line segment, and the above The contact point with the peripheral edge of the rectangular area and the contact point with the fifth line segment of the first piece and the peripheral edge of the rectangular area are specified as the first contact point, the second contact point, and the third contact point, respectively. A procedure for recognizing a contact point between the first first line segment or the first third line segment and the peripheral edge of the rectangular area as a fourth contact point, and the first contact point and the first contact point. A procedure for setting a ninth line segment connecting the second contact point and a tenth line segment connecting the first contact point and the third contact point, and a procedure for setting a ninth line segment parallel to the ninth line segment. By setting the virtual line of No. 1 and moving it from the second contact toward the fourth contact,
Of the line segment, the second line segment, the sixth line segment, and the third line segment, and setting a second virtual line parallel to the tenth line segment A procedure for recognizing the fifth line segment, the fourth line segment, the eighth line segment, and the first line segment by moving from the third contact toward the fourth contact. And a procedure for calculating the capacity of the data in the data part based on the recognized numbers of the second, fourth, sixth, and eighth line segments, and one of the sides forming the peripheral edge of the rectangular area. A procedure for setting the coordinate system having the X-axis or the Y-axis on two orthogonal sides to specify the coordinates of each cell in the data part, and converting the symbolized data into bit string data based on the cell coordinates. A method for reading a two-dimensional code is provided, which comprises:

Further, according to the present invention, there is provided a program for causing a computer to execute the above-described two-dimensional code reading method according to the present invention, and a computer-readable recording medium recording the program.

[0013]

DETAILED DESCRIPTION OF THE INVENTION Some embodiments of the present invention will be described below with reference to the drawings.

(1) Embodiment of two-dimensional code FIG. 1 is a schematic view showing an embodiment of a two-dimensional code according to the present invention. As shown in the figure, the two-dimensional code 1 of the present embodiment is arranged so as to surround the matrix data part 2 and the matrix data part 2 in which the binarized data is stored in the form of bright and dark square cells. Line segment LS11
To LS14 (first line segment), LS31 to LS34 (third line segment)
Line segment), LS51 to LS54 (fifth line segment), LS7
1 to LS74 (seventh line segment) and headline lines R21 to R2 vertically extending from substantially central portions of these line segments, respectively.
4 (second line segment), R41 to R44 (fourth line segment), R
61 to R64 (sixth line segment), R81 to R84 (eighth line segment), and L-shaped graphic LC whose both ends are continuous with the ends of LS54 and LS74.

The matrix data section 1 has an x direction and ay direction.
It is composed of nine small regions (see FIG. 2) arranged adjacent to each other in three directions (L = M = 3). In the small area, N (N is a natural number) data cells are arranged adjacent to each other in both the x and y directions. In the present embodiment, the number of small regions is the same in both the x direction and the y direction, but the number of small regions is not limited to this and can be changed independently in the x direction and the y direction.

The line segment described above is the first line segment in this embodiment.
And the graphic LC forms the second graphic in the present embodiment. From these, the data density information (print pitch) and the rotation angle of the matrix data portion are given by using the reading method described later. The width of each line segment is
The length of one side of the data cell is the same, and the length of each line segment is determined with the length of one side of the data cell as a basic unit.

The line segments LS11 to LS14 are arranged along the side a of the quadrangle forming the periphery of the matrix data portion 2 at a pitch that matches the size of the small area. Similarly, the line segments LS31 to LS34 are arranged along the side b at a pitch that matches the size of the small area. On the other hand, the line segments LS51 to LS54 are spaced apart from the side c and arranged along a line parallel to the side c at a pitch that matches the size of the small area. Similarly, line segments LS71 to L
S74 is also spaced apart from the side d and arranged along a line parallel to the side d at a pitch that matches the size of the small regions.

The heading lines R21 to R24 indicate the positions of the specific data cells in the row direction or the column direction, respectively. The headline lines R21 to R24 are arranged so as to extend from the line segments LS11 to LS14 toward the outside of the matrix data unit 2, respectively. Similarly, the headline lines R41 to R44 are arranged so as to extend from the line segments LS31 to LS34 toward the outside of the matrix data unit 2, respectively. On the other hand,
The headline lines R61 to R64 are arranged so as to extend from the line segments LS51 to LS54 toward the matrix data unit 2. Similarly, the headline lines R81 to R84 are arranged so as to extend from the line segments LS71 to LS74 toward the matrix data unit 2, respectively.

In the present embodiment, the lengths of the heading lines are all the same, but the heading lines R61 to R64 facing inward,
Line segments LS51 to LS54 and line segments LS71 to L so that R81 to R84 do not overlap the matrix data unit 2.
S74 is arranged apart from the peripheral edge of the matrix data section 2.

The number of heading lines can be increased or decreased independently in each of the horizontal and vertical directions depending on the number of small areas included in the matrix data section 2 and the arrangement of the small areas. Therefore, it is possible to configure the two-dimensional code of various sizes and shapes depending on the usage of the data volume and the place to print.

The L-shaped figure LC has line segments LS54 and L
Since there is a continuous orthogonal portion at the end of S74, the rotation angle of the data cell can be obtained by setting the rectangular area AR for clipping so as to contact the corner A in the image processing at the time of reading described later. Further, the corner A can be used as the origin of the two-dimensional code 1 to specify the position coordinates of each cell, as described later.

Thus, the two-dimensional code 1 of this embodiment is
In the above, since there is no special print pattern for cutting out, positioning, etc. in the matrix data section 2, it is possible to mount more data in a smaller area. Further, even if the data capacity is increased, the cutting and positioning can be performed only by the first and second figures surrounding the matrix data section 2, so that the area occupied by the entire two-dimensional code is proportional to the increase in the data capacity. Much smaller than what you do. This provides a two-dimensional code that stores a large amount of information at a high density.

(2) Embodiment of Method for Reading Two-Dimensional Code Next, the method for reading the two-dimensional code shown in FIG. 1 will be described as an embodiment of the method for reading a two-dimensional code according to the present invention. Here, only the reading procedure peculiar to the two-dimensional code according to the present invention is shown, and the detailed procedures and adjustments generally required for the reading process are omitted.

FIG. 2 is an explanatory view of the reading method of this embodiment, and FIG. 3 is a flow chart showing a schematic procedure of the reading method shown in FIG.

1) First, digital image data of the two-dimensional code 1 is taken in using an image pickup device such as a CCD (step S1).

2) Next, the distribution (histogram) in which vertical and horizontal dark cells exist in this image data is examined, and a rectangular area AR surrounding the two-dimensional code 1 is defined as shown in FIG. 2 (step S2). .

3) Next, a point in contact with each side of the peripheral edge of the rectangular area AR is searched (step S3). In the case of FIG.
Points A, E, F and H are obtained.

4) Subsequently, the dots on the straight line connecting the points A, E, F and H adjacent to each other are examined,
It is determined where a corner is formed by a dark line segment (step S4). In the case shown in FIG. 2, the straight line A
It can be seen that such a line segment exists at the intersection of E and the straight line AF and its vicinity. On the other hand, straight line EH and straight line FH
There are no dark areas that make up the corners. An intersection A between the straight line AE and the straight line AF is selected as the origin of the two-dimensional code 1 (step S5). Accordingly, the rotation angle of each data cell can be obtained by obtaining the angle θ between the straight line AE and the side of the rectangular area AR.

5) Next, a straight line AF that is parallel to the straight line AF
A line segment whose length is almost the same as that of the upper line segment LS54 is examined from the point A to the point E, the line segment LS14 is specified, the point B is specified from the end point thereof, and further, on the extension line of this line segment LS14. Point H is specified. Similarly, a line segment LS61 and a line segment LS31 which are parallel to the straight line AE from the point A to the point F and have substantially the same lengths as the line segment LS74 and the line segment LS71 on the straight line AE are examined, C and the point G are obtained, and the intersection D between the straight line BH and the straight line CG is specified (step S6).

6) Next, a virtual broken line (heading broken line) parallel to the line segment AF and having the same length is set, and scanning is started from the point A to bd1, bd2 ... In the direction of the point E. , Headlines R44 and R84, R43 and R83, R
42 and R82 are searched (step S7). At this time, a heading broken line bd1 connecting the heading lines R44 and R84
Since the distance from the point A to the point A and the length and pitch of each heading line are known constants with the size of the data cell as a unit, based on the positional relationship between the points A to D already specified in the above procedure. The position of each headline can be predicted. Similarly, an imaginary broken line that is parallel to the line segment AE and has the same length is set, and ac1 and ac are set in the direction from the point A toward the point F.
By scanning 2 ..., heading lines R24 and R64,
R23 and R63 and R22 and R62 are searched (step S7). Here, the number of headline lines recognized as extending vertically from the line segment AC to the matrix data unit 2 (four lines of R61 to R64 in the present embodiment) and the line segment BD to the matrix data unit 2 Is the same as the number of each heading line recognized as extending vertically toward the outside of the line (4 lines of R21 to R24 in this embodiment), and similarly, from the line segment AB to the matrix data portion 2 To the outside of the matrix data part 2 from the line segment CD and the number of headline lines recognized as vertically extending toward (4 in this embodiment, R81 to R84). If the number of heading lines (four in this embodiment, R41 to R44) is the same, it can be confirmed that each heading line is normally searched. Further, as described above, the number of heading lines is independently determined in each of the horizontal direction and the vertical direction according to the number of data in the matrix data portion 2, and therefore the number of heading lines recognized in each line segment. According to the above, the capacity of the matrix data is determined.

7) Then, as shown by the broken line in FIG.
Line segments bd1 to bd3 and ac1 to ac3 that form a lattice shape by sequentially connecting the points on the heading lines recognized by the two parallel sides of the polygon ABCD are assumed again, and the intersections n11 to n11 of these line segments are assumed. The coordinates of n33 are calculated (step S8). These coordinates correspond to the coordinates of the data cells in the matrix data unit 2 extracted at equal intervals.

8) Further, from the coordinates of the intersection obtained in 7) above, the coordinate value of each cell is obtained from the known number of cells between the header lines, and the binary value of each cell is sampled to obtain the bit string data. (Step S9).

9) Finally, since an error correction code is added in advance to the bit string data of the two-dimensional code 1, error correction is performed using this. As a result, the original data is restored (step S10).

As described above, according to the two-dimensional code reading method of the present embodiment, the index line segment having a length determined with the length of one side of the data cell as a basic unit is stored in the matrix data section 2 at a predetermined pitch. Since the data cells in the matrix data unit 2 are equally divided by using the peripheral arrangement, and the position coordinates thereof are obtained, the binarized data can be restored with high accuracy by simple image processing, and the data capacity can be increased. Can also get quickly.

(3) Program and Recording Medium The series of procedures of the above-described two-dimensional code reading method may be incorporated into a program and read by a computer capable of processing image data to be executed. As a result, the two-dimensional code reading method according to the present invention can be realized using a general-purpose computer. Further, a series of procedures of the above-mentioned two-dimensional code reading method may be stored in a recording medium such as a flexible disk or a CD-ROM as a program to be executed by a computer capable of processing image data, and may be read and executed by the computer. . The recording medium is not limited to a portable one such as a magnetic disk or an optical disk, and may be a fixed recording medium such as a hard disk device or a memory. Further, a program incorporating a series of procedures of the above-described two-dimensional code reading method may be distributed via a communication line (including wireless communication) such as the Internet.
Furthermore, a program incorporating a series of procedures of the above-mentioned two-dimensional code reading method may be encrypted, modulated, or compressed in a state in which it is stored in a recording medium via a wired or wireless line such as the Internet. It may be stored and distributed.

Although some of the embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments.
Needless to say, various modifications can be made within the technical scope.

[0037]

As described in detail above, according to the present invention,
Provided are a large-capacity and small-size two-dimensional code which can be printed by a general-purpose laser printer and can secure sufficient positioning accuracy, a reading method thereof, a program, and a computer-readable recording medium.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of a two-dimensional code according to the present invention.

FIG. 2 is an explanatory diagram of an embodiment of a two-dimensional code reading method according to the present invention.

FIG. 3 is a flowchart illustrating a schematic procedure of the reading method shown in FIG.

[Explanation of symbols]

1 two-dimensional code 2 matrix data parts bd1 to bd3, ac1 to ac3 virtual broken lines LS11 to LS14 first line segments LS31 to LS34 third line segments LS51 to LS54 fifth line segment) LS71 to LS74 seventh line segment LC L-shaped figure (second figure) R21 to R24, R41 to R44, R61 to R64, R
81-R84 Heading line (2nd, 4th, 6th, 8th line segments)

Claims (5)

[Claims] 1. A data part arranged so that bits of binarized data are symbolized as square data cells of a light part or a dark part to form a two-dimensional matrix, and arranged in a peripheral part of the data part, A two-dimensional code comprising: a first figure that gives information about the print pitch of the cell; and a second figure that is provided around the data part and that gives information about the direction of rotation of the cell. The data portion has L square (L) small areas each having N (N is a natural number) adjacent to each other in the first and second directions orthogonal to each other. Is a natural number) and M pieces (M is a natural number) are arranged adjacent to each other in the second direction, and the shape of the peripheral edge of the data part is the first side in the second direction and the first side. The second side orthogonal to the side of 1 and each other A rectangular shape having a third side and a fourth side that are orthogonal to each other and that face the first side and the second side, respectively, and the first figure is close to the data section along the first side. (M + 1) first line segments that are arranged in such a manner that they are spaced apart from each other at a pitch corresponding to the size of the small area, starting from the vicinity of the intersection of the first side and the second side. And (M + 1) second line segments which are provided so as to respectively project from the substantially center of the first line segment in the first direction toward the outside of the data section, It is arranged close to the data part along the side of 2 and is separated from each other at a pitch according to the size of the small area with the apex of the first line segment as a starting point ( L + 1) third line segments, in the second direction and toward the outside of the data portion The (L + 1) fourth line segments provided so as to respectively project from substantially the center of the second line segment, and are arranged apart from the data section along a line parallel to the third side. And (M + 1) fifth line segments spaced apart from each other with a pitch on the line connecting the vertices of the fourth line segment according to the size of the small region, and the corresponding (M + 1) sixth line segments which are respectively arranged on the extension lines of the second line segment and which extend from substantially the center of the fifth line segment toward the data section side. , Spaced apart from the data part along a line parallel to the fourth side, and starting from one point on the line connecting the vertices of the second line segment, with a pitch according to the size of the small region, (L + 1) seventh line segments arranged apart from each other, and corresponding extended lines of the fourth line segment And an eighth line segment that is respectively arranged above and that is provided so as to project from substantially the center of the seventh line segment toward the data section. An L-shaped graphic provided so as to be continuous with the (M + 1) th fifth line segment and the (L + 1) th seventh line segment, wherein the fifth line segment and the seventh line segment A minute is arranged apart from the data part such that the apex of the sixth line segment and the apex of the eighth line segment are separated from the third side and the fourth side, respectively. Dimension code. 2. The length of each of the first line segment to the eighth line segment is determined with a length of one side of the data cell as a basic unit. Two-dimensional code. 3. The method for reading a two-dimensional code according to claim 1, wherein the image of the two-dimensional code is acquired, and a margin is the second figure in the acquired image. A rectangular region that is in contact with the corner portion of and surrounds the pattern so as to include at least a part of the fifth line segment of the first piece and at least a part of the seventh line segment of the first piece. And a contact point with the corner portion, a contact point between the seventh line segment of the first piece and the peripheral edge of the rectangular area, and a fifth line segment of the first piece and the rectangular area. The first contact point with the peripheral edge
Of the first line segment or the third line segment of the first piece and the peripheral edge of the rectangular area are identified as the first contact point, the second contact point and the third contact point. A procedure for recognizing the contact point of No. 4 and a ninth line segment connecting the first contact point and the second contact point are set, and a first line connecting the first contact point and the third contact point is set.
The procedure of setting a line segment of 0, and setting a first virtual line parallel to the ninth line segment and moving the virtual line from the second contact toward the fourth contact, Of the line segment, the second line segment, the sixth line segment, and the third line segment, and setting a second virtual line parallel to the tenth line segment, A procedure for recognizing the fifth line segment, the fourth line segment, the eighth line segment, and the first line segment by moving from the third contact toward the fourth contact. And a procedure for calculating the capacity of the data in the data part based on the recognized numbers of the second, fourth, sixth, and eighth line segments, and one of the sides forming the periphery of the rectangular area, A step of setting a coordinate system having two orthogonal sides as an X-axis or a Y-axis and specifying coordinates of each cell in the data part; Two-dimensional code reading method comprising, a step of converting the symbolized data on bit array data based on. 4. A program for causing a computer to execute the method for reading a two-dimensional code according to claim 3. 5. A computer-readable recording medium recording a program for causing a computer to execute the method for reading a two-dimensional code according to claim 3.