JP2007048322A - Reading method of two-dimensional information code - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To record data at high density by carrying out display using colors, to enable error detection and to shorter a reading time. <P>SOLUTION: A plurality of cells 4 are arranged in a matrix-like form, and data display colors are allocated to and set in positioning patterns 2a-2e as specific patterns so as to include all of them. White, black, red, green and blue are set as the data display colors; white and black having high contrast are set in the positioning pattern 2a; and white is set in the other parts by combining it with the other colors. In reading, by reading the positioning pattern, its presence range can be surely detected and the data display color used as a reference can be identified, and the color of each cell 4 in a data area 3 can be surely determined. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for reading a two-dimensional information code having as constituent elements information display unit cells arranged in a matrix and a specific pattern serving as a position reference for specifying the positions of the information display unit cells.

  As this type of two-dimensional information code, there is generally one in which black and white cells are arranged in a matrix to display data values. However, since one cell is expressed by bit information of white or black, reading processing is performed. Can be decoded by a simple binarization process, but the density cannot be increased any more as the amount of information.

  Therefore, it is considered to display information at a high density by colorizing the display of cells as a unit for displaying information. As the method, for example, in addition to black and white in one cell, colors such as red, blue, and green are displayed corresponding to the data value, so that the cell data is represented by two values “0” and “1”. Is increased to five values “0” to “4”. The reading process is performed by determining the color of the cell at the time of reading and making it correspond to the data value.

In the above colorization, it is important to accurately read the color displayed in the cell, and in order to ensure this, conventionally, for example, by implementing a color sample near the matrix. (For example, refer to Patent Document 1). In addition, there is a method for generating a color information code for a barcode (for example, see Patent Document 2).
JP-A-10-283446 JP 2000-67191 A

  The conventional techniques as described above have not been sufficiently technically available in the following points, which has been a problem in practical use. That is, when data is recorded at a high density using many colors, firstly, it is difficult to detect the existence area of the two-dimensional information code, and secondly, an error occurs in determining the color of the information display unit. There are problems such as easy to do.

  Since such problems occur, as a result, there is a technical problem that the time required for reading becomes longer and the amount of error correction increases, and it is necessary to solve these problems. .

  The present invention has been made in view of the above circumstances, and an object of the present invention is to quickly detect the existence area when displaying using colors, and to shorten the time required for reading. Another object of the present invention is to provide a method for reading a two-dimensional information code that can reduce the amount of error correction.

  According to the first aspect of the present invention, as the components of the two-dimensional information code, information display unit cells arranged in a matrix, and a specific pattern serving as a position reference for specifying the positions of the information display unit cells And three or more data display colors that can be read by optical means are set corresponding to the data values shown for each information display unit cell, and displayed in the information display unit cell from among the data display colors. The data display color corresponding to the data value is displayed, and since the color reference cell indicated by assigning all the data display colors used for the information display unit cell to the specific pattern is displayed, this color reference cell is included. The specific pattern is read and its position and data display color are taken in, so that the data display color used in the information display unit cell can be read reliably. As a result, the existence range can be reliably recognized, and data can be displayed at a high density in the information display unit cell. In other words, it can be displayed using a small two-dimensional information code. become able to.

  Then, when reading the above two-dimensional information code, the process of setting the data display color assigned to the positioning pattern as the detection color, and the binarization of the first stage for the image data based on the detection color A process of detecting a positioning pattern in the binarized image data; calculating first and second color reference cell positions included in the detected positioning pattern; and first and second reference colors Included in each of the specific patterns, a process of detecting the position of the specific pattern including the color reference cells of other colors based on the detected position and size of the positioning pattern, and The process of calculating the position of the color reference cell, detecting each reference color and storing it in the storage means, and displaying information based on the detected reference color stored in the storage means The process of identifying the data display color of the unit cell, the process of restoring the recorded data based on the data display color of the information display unit cell, and checking the restored data for errors, and correcting any errors. Therefore, the existence range can be detected quickly and surely based on the data display color information read from the specific pattern, and the information display unit cell information can be read.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Here, regarding the description of the two-dimensional information code, first, various examples of the two-dimensional information code are shown, and then the reading method will be described.

(1) Outline description of two-dimensional information code (1-1) Example of two-dimensional information code FIG. 1A shows a two-dimensional information code 1 which is an example of a two-dimensional information code according to the present invention. ing. The two-dimensional information code 1 is displayed by a method such as printing on a label or the like in the same manner as a general barcode, and is attached to an article. In the two-dimensional information code 1, for example, various information such as a product serial number, a product name, a unique identification number, a manufacturing date, and a manufacturer are recorded.

  As shown in the figure, the two-dimensional information code 1 is composed of positioning patterns 2a to 2e as specific patterns, a data area 3, and the like. The data area 3 is set so that a data value and a correction code for error correction at the time of reading the data value are displayed in a predetermined area.

  The two-dimensional information code 1 is formed by arranging a large number of square information display unit cells (hereinafter simply referred to as cells) 4 in a matrix, for example, 26 cells vertically and horizontally, and a part of them is positioned in the positioning patterns 2a to 2e. The remaining area is used as a data area 3.

  Each cell 4 is represented using one of the first to fifth data display colors. As the data display colors, the first to fifth colors “white”, “black”, “red”, “green”, and “blue” are assigned, respectively. The first data display color “white” and the second data display color “black” are selected with the highest contrast. As the third to fifth data display colors, three primary colors of light are selected in consideration of optical reading. These data display color selection settings are not limited to those in the present embodiment, and any color can be used as long as it is a color that can be optically read and identified.

  Now, the positioning patterns 2a to 2e are the first large positioning pattern 2a arranged in the upper left as shown in the figure, and the small size sub-patterns arranged in the lower left, lower right, upper right, and center respectively. The second to fifth positioning patterns 2b to 2e. The first positioning pattern 2a is composed of three parts, an outer frame, a middle frame, and a center part, and the other positioning patterns 2b to 2e are composed of an outer frame and a center part.

  And as for each positioning pattern 2a-2e, as shown in following Table 1, the color of each part is set. In this embodiment, the middle frame or the center is set to “white”, and the outer frame is sequentially set to another color (in the drawing, it is displayed with shading, but the corresponding data display color is It is shown in the figure).

上記のような構成とすることで、セル４に用いるデータ表示色のすべてについて、位置決めパターン２ａ〜２ｅで示しているので、読み取り時には、これらを読み取って位置と範囲を特定する際に色情報もすべて得ることができるので、セル４のデータを確実に読み取ることができる。なお、具体的な読取処理については、後述する。

With the above configuration, all the data display colors used in the cell 4 are indicated by the positioning patterns 2a to 2e. Therefore, when reading, color information is also obtained when reading these to identify the position and range. Since all data can be obtained, the data in the cell 4 can be read reliably. The specific reading process will be described later.

(1-2) Modification A of two-dimensional information code
Next, FIGS. 1B and 1C show a modification of the two-dimensional information code 1 described above. In this modification, the data display color of the positioning pattern is set to be different. In FIG. 5B, for example, the data display color indicating the second positioning pattern 2b is set to a different color.

  Here, for example, the center of the second positioning pattern 2b is set to “red” as the third color, and the peripheral portion is set to “black” as the second color. In addition, the data display colors used for the other positioning patterns 2a, 2c to 2e can be exchanged and set in a similar manner. In any case, any one of the positioning patterns 2a to 2e may include the first color (white) to the fifth color (green).

  In FIG. 8C, for example, when the color of the background portion K of the portion displaying the two-dimensional information code is dark such as “black”, it is used for the outer frame portion of each positioning pattern 2a to 2e. This is a case of using a two-dimensional information code in which the data display color is set to a light color system such as “white”. In this case, in (1-1), in the middle frame or the central portion of the positioning patterns 2a to 2e, which is a portion using “white” as the first color, the second color “ Display using “black”. That is, the display is made by inverting “white” and “black”. As a result, the contrast with the background color is increased to ensure reading.

(1-3) Modified example B of two-dimensional information code
2D, 2E, and 2F show two-dimensional information codes 5, 6, and 7 in which different specific patterns are set. First, the two-dimensional information code 5 shown in FIG. 4D is a matrix in which 15 cells are arranged in a matrix in each of vertical and horizontal directions. 5d is provided.

  In this two-dimensional information code 5, the positioning pattern 5a located at the upper left is set by “white” and “black” in the same manner as described above, and “black” is excluded from the four-color reference pattern 5b located at the lower right. This is a pattern composed of four cells 4 in which the other four colors (“white”, “red”, “green”, “blue”) are arranged corresponding to each cell 4.

  In addition, the timing patterns 5c and 5d are set in units of a left vertical column and an upper horizontal column, respectively. In these timing patterns 5c and 5d, “white” and other colors are alternately arranged to show all data display colors. For example, in the timing pattern 5c, white, green, white, red, white, blue, white, green, white, and red data display colors are set in the respective cells 4 in order from the left.

  In FIG. 8E, the two-dimensional information code 6 is a matrix in which 31 cells are arranged in a matrix in the vertical and horizontal directions. As a specific pattern, the positioning pattern 6a arranged in the upper left, lower left, lower right, upper right Three color reference patterns 6b to 6d arranged respectively, and specific patterns 6g to 6k located at the center of each side and the center of the whole are provided.

  In the color reference patterns 6b to 6d, “red”, “green”, and “blue” are arranged in the outer frame, and “white” is arranged in the center. For the specific patterns 6g to 6k, the outer frame is arranged as “black” and the central portion as “white”.

  In FIG. 8 (f), the two-dimensional information code 7 has 19 cells each in vertical and horizontal directions and is arranged in a matrix, and has a medium size between the two-dimensional information codes 5 and 6 described above. is there. In the two-dimensional information code 8 as well, the positioning pattern 7a is arranged in the upper left part and is shown as a color reference pattern in the other corners as described above.

(2) Block Structure of 2D Information Code Next, the block structure of the 2D information code 1 will be briefly described. In the two-dimensional information code 1 used in this embodiment, as shown in FIG. 3B, a block B is configured with four cells 4 as one set. This block size is set on the condition that it can cover the data size when 8 blocks are one block in the conventional method expressed by “white” and “black”. That is, the block B is configured to indicate one data in units of 4 cells.

  That is, in the case of two colors of “white” and “black”, if 8 cells are used, the range of data values that can be taken is 28, which is 256. On the other hand, in the case of this embodiment shown in five colors, 54 is 625 because four cells are used. This data value range corresponds to 9 cells (9 bits = 512 data values) in terms of the expression “white” and “black”. This correspondence is shown in the cell layout diagram of FIG.

  Next, a data expression method will be described. As described above, as the data display colors, the first to fifth colors “white”, “black”, “red”, “green”, and “blue” are assigned, respectively. The following values are associated with each color. That is, the first color “white” for the data value “0”, the third color “red” for the data value “1”, the fifth color “green” for the data value “2”, A fourth color “blue” is set for the data value “3”, and a second color “black” is set for the data value “4”.

  Next, the relationship between the data value of block B and the color will be described. Now, considering the case where the data value is “0”, in the case of FIG. Similarly, in the present embodiment, all of the four cells 4 are set to “white”. However, in this embodiment, in order to avoid that all the blocks B of the data area 3 of the two-dimensional information code 1 become “white”, a certain value is added to the data value to be displayed. The data that has been raised is displayed.

  This is because the range of data values that can be expressed by this block B is “625” with respect to the range of “512” of 9-bit data values shown in FIG. There is room to express. Therefore, even if the data value is “0”, the raised value is set to “86”, that is, “1, 2, 3, 0 ( When data are arranged in order from the bottom digit), the data display colors “red”, “green”, “blue”, and “white” are set.

  As a result, in the expression of the data value “255” of the conventional method as shown in FIG. 4D, the data value of each cell is “1,1,1,1,1,1,1,1,0”. Therefore, 8 cells become “black” and the remaining one cell becomes “white”, whereas the data value “255” is converted as it is, and the data value “0, 1, 0, 2” , And adding “86”, that is, “1, 2, 3, 0”, to the data value “1, 3, 3, 2”, the four cells 4 have “red”, “green”, The data display colors “blue” and “white” are set.

  As a result, a block B that can represent the same amount of data as a block corresponding to 9 cells (9 bits) obtained by adding 1 cell to 8 cells of the conventional method is expressed using 4 cells 4. Furthermore, by shifting (raising) the data value, the displayed color can always include a plurality of data display colors, and the boundaries of the information display unit cells can be easily identified. It becomes easy to process.

(3) Generation process of two-dimensional information code Next, a process in the case of generating the above-described two-dimensional information code 1, 5, 6, 7, etc. will be described with reference to FIG. This will be described with reference to the dimension information code 1). This generation processing is performed by a control device capable of data processing such as a computer.

  First, the control device generates an error correction code for the data value of the two-dimensional information code 1 to be generated by calculation (step S1). Next, the data and the error correction code are divided into blocks B (step S2). For each block B obtained, an error detection code for each block is calculated and added to calculate a block value (step S3). , S4).

  The control device assigns a data display color corresponding to the data value of the obtained block B, arranges it in a two-dimensional area, and generates image data (steps S5 and S6). Subsequently, the control device generates image data using the set data display color corresponding to the positioning block set as the specific pattern (step S7).

  If there is blank data in the data area 3, image data is generated by arranging blocks set in the data display color indicating the raised data “86” corresponding to the data value “0” in the area. (Step S8). Through the above processing, the two-dimensional information code 1 is obtained, and the control device outputs the image data. The output image data can be displayed in various ways in accordance with the case where the two-dimensional information code 1 is displayed by printing, the case where the two-dimensional information code 1 is displayed by an electric means on the display device, or the like.

(4) Reading process of two-dimensional information code (4-1) Configuration of reading device Next, processing when reading the two-dimensional information code 1, 5, 6, 7 and the like configured as described above by the reading device 10 explain. FIG. 4 shows the electrical configuration of the two-dimensional information code reader 10.

  The reading device 10 includes, for example, a hand-held type and a stationary type, and each includes an optical reading unit and a data processing unit. As an optical reading unit, LEDs 11 and 12 that project white light from a plurality of directions onto a recording surface D such as a sheet on which the two-dimensional information code 1 to be read is recorded and images of the recording surface D are displayed. A lens 13 for photographing and a CCD (Charge Coupled Device) image sensor 14 are provided.

  The entire internal control is performed by the control unit 15. The control unit 15 is provided with an internal memory, an interface, and the like mainly using a CPU, and stores a reading processing program. The above-described output terminal of the CCD image sensor 14 is connected to the memory 18 via the amplifier circuit 16 and the A / D conversion circuit 17. In addition, the output terminal of the A / D conversion circuit 17 is connected to the memory 18 via the specific ratio detection circuit 19.

  An image signal photographed by the CCD image pickup device 14 is amplified in an analog manner by an amplifier circuit 16, converted into a digital signal through an A / D conversion circuit 17, and stored in a memory 18 as binarized image data. The In this embodiment, the captured image of the two-dimensional information code 1 captured by the CCD image sensor 14 is captured as a color image, converted into a digital signal, and then light / dark image data, R (red) image data, G Each of (green) image data and B (blue) image data is stored in the memory 18.

  The CCD image pickup device 14 and the specific ratio detection circuit 19 are supplied with a synchronization signal from a synchronization signal generation circuit 20. The synchronization signal generation circuit 20 provides a synchronization signal also to the address generation circuit 21, and provides an address signal to the memory 18. The LEDs 11 and 12, the amplifier circuit 16, the A / D conversion circuit 17, the specific ratio detection circuit 19 memory 18, and the synchronization signal generation circuit 20 are configured to receive a control signal from the control unit 15 and to exchange information. Yes.

  The reading device 10 is provided with an operation switch 22 for performing various operation inputs, and the control unit 15 receives inputs. Further, the control unit 15 is provided with an LED 23, a buzzer 24, a liquid crystal display 25, and the like for displaying a control state and performing a notification operation. Furthermore, a communication interface 26 for communicating with an external device is connected.

(4-2) Explanation of Reading Processing FIG. 6 shows the processing contents of the reading processing program, and the control unit 15 gives a control signal to each unit to execute the reading processing. First, the light emitting LEDs 11 and 12 are turned on, and an image of the recording surface D is taken by the CCD image pickup device 14. At this time, white light is projected from the LEDs 11 and 12, and the two-dimensional information code 1 displayed in the color recorded on the recording surface D is photographed (step P1).

  The image signal from the CCD image pickup device 14 is divided into three RGB signals, and at this time, light / dark image data is obtained from these signals by calculation and stored in the memory 18 together with the RGB image data (step). P2). Next, the control unit 15 performs a decoding process on the two-dimensional information code 1 based on the read image data. First, the specific patterns, that is, the positioning patterns 2a to 2e are searched from the light / dark image data (step P3).

  When detecting the position of the specific pattern, the control unit 15 specifies the existence area of the two-dimensional information code 1 based on the position (step P4). Next, each color reference value assigned to the positioning patterns 2a to 2e of the specific pattern is acquired, and a threshold for determining each data display color is set (step P5). This principle will be described later.

  Thereafter, the control unit 15 determines and specifies the data display color of each cell in the data area 3 based on the threshold value obtained as described above (step P6). Next, each cell 4 in the data area 3 is divided into the set block B (step P7), and the data value set in each block is obtained (step P8). At this time, the presence / absence of an error is also checked, and if an error exists, an error correction process is performed using a correction code (step P9). When the above processing is repeated and data values are obtained for all blocks, the data is output (step P10).

  In the above case, the threshold value setting process performed in step 5 of the control unit 15 can be obtained by a logical calculation as follows. FIG. 7 shows the principle. That is, when the image data is converted from an analog signal to a digital signal, it is necessary to discriminate each of the RGB signals. For example, in the R image signal level, the “red” signal level and the “white” signal level are determined. There is no big difference in level, and it becomes a level similar to “bright”. On the other hand, in the signal level of the R image, the signal levels of “black”, “green”, and “blue” are not significantly different, and are similar to “dark”.

  As for this tendency, in the signal level of the G image, “green” and “white” are “bright” levels, and “black”, “red”, and “blue” are “dark” levels. Similarly, in the signal level of the B image, “blue” and “white” are “bright” levels, and “black”, “red”, and “green” are “dark” levels. Therefore, in all the determinations, “white” when the signal level is “light”, “black” when the signal level is “dark”, and only when the image data has its own data display color “ When “bright” is “dark” in other image data, it can be determined as the data display color. By setting the threshold value as described above, the data display color for each cell can be reliably determined based on each image data.

  Since each data display color is arranged at a predetermined position in the specific pattern, when setting a threshold for determining the data display color, the threshold is set with reference to this. For example, an intermediate level between red and white brightness levels and blue, green, and black brightness levels is set. By performing this for each data display color, it is possible to set a threshold value that can be reliably determined.

(5) Description of split display of two-dimensional information code FIG. 8 shows a display example when split display of the two-dimensional information codes 1, 5, 6, 7 and the like. This is a display method that is effective when, for example, the size of the two-dimensional information code 1 is large and the display area for displaying the code is limited. In other words, when the area for displaying pre-generated or generated data is narrow and all cells cannot be displayed at once, the two-dimensional information code that is configured to be large is divided and displayed sequentially. It is a thing.

  A method of the division display will be briefly described. The size of the number of displayable cells is set with respect to the size corresponding to the original number of cells of the two-dimensional information code to be displayed. At this time, the number of divisions (for example, 4) is determined from the corresponding number of cells.

  Next, the data value of the original two-dimensional information code is divided into the number of divisions described above and given an order according to the order (A, B, C, D). Each divided data value is converted into a corresponding partial two-dimensional information code having the number of cells set as described above (see FIG. 5B). Thereby, a set of partial two-dimensional information codes is generated. When the display is performed, the display is switched and displayed at a predetermined timing in the order of order (see (a) in the figure).

  During the reading process, the sequentially fetched two-dimensional information code is decoded, and when it is recognized that there is an order, when a predetermined number is fetched, it is fetched as a set of two-dimensional information code data. Thereby, even in a compact display area, it is possible to display a two-dimensional information code corresponding to a large size. In this embodiment, as described above, since the two-dimensional information code is set to be displayed in color, a more compact display can be performed, in other words, an efficient display with a large amount of information can be performed. Will be able to.

The present invention is not limited to the above embodiment, and can be modified or expanded as follows.
Although only the error detection code is added to the data block B, an error correction code having an error correction function may be included. As a result, the function of correcting the error location can be achieved by the individual block, so that it can be recognized quickly and accurately.

  In addition to the five colors described above, various data display colors can be used as long as they can be read optically. The data display color is not limited to five colors, and a data display color within a possible range of three or more colors can be used. Can be used.

Display example of two-dimensional information code showing one embodiment of the present invention Display example of two-dimensional information code shown in different patterns Diagram for explaining data block Two-dimensional information code generation processing program Electrical configuration diagram of two-dimensional information code reader Two-dimensional information code reading processing program Illustration of level judgment of image signal Illustration of split display of 2D information code

Explanation of symbols

  1, 5, 6 and 7 are two-dimensional information codes, 2a to 2e are positioning patterns (specific patterns), 3 is a data area, 4 is an information display unit cell, 5c and 5d are timing patterns, 10 is a reader, Reference numeral 12 denotes an LED, 14 denotes a CCD image pickup device, 15 denotes a control unit, 18 denotes a memory, and 19 denotes a specific ratio detection circuit.

Claims (1)

The information display unit cells arranged in a matrix and specific patterns serving as position references for specifying the positions of the information display unit cells are used as constituent elements, and the data values shown for each of the information display unit cells Correspondingly, three or more data display colors readable by optical means are set, and the information display unit cell displays a data display color corresponding to a data value displayed in the cell from among the data display colors. The specific pattern is a two-dimensional reading of a two-dimensional information code provided to be displayed including a color reference cell assigned with all the data display colors used for the information display unit cell. In the information code reading method,
The process of setting the data display color assigned to the positioning pattern as the detection color,
A process of performing binarization of the first stage on the image data based on the detected color;
The process of detecting the positioning pattern in the binarized image data,
Calculating the first and second color reference cell positions included in the detected positioning pattern, detecting the first and second reference colors and storing them in the storage means;
Determining a position of a specific pattern including a color reference cell of another color based on the detected position and size of the positioning pattern;
Calculating the position of the color reference cell included in each specific pattern and detecting each reference color and storing it in the storage means;
Identifying the data display color of the information display unit cell based on the detected reference color stored in the storage means;
Restoring the recorded data based on the data display color of the information display unit cell;
A method for reading a two-dimensional information code, comprising: checking errors of restored data and performing correction processing if there is an error.

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