JPH11353436A - Emblem code and its coding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the emblem code which can be read mechanically by a computer and can represent its meaning in form that a human understands and it coding method. SOLUTION: Each cell 1 in a data are 10 constituting a two-dimensional code is given color information. Paying attention to lightness and a color as two feature quantities of color information, mechanically read information is represented by a difference in lightness (light and dark) and a design shape that a human can recognize is represented by a difference in color (green and yellow). Those two feature quantities are put on over the other, cell by cell, to multiply the mechanically read information and design shape. The meachanically read information is demodulation by extracting only feature quantities regarding the lightness from multiplied emblem codes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a code which can be machine-recognized by a data processing device and which can represent the meaning of the information of the code in a form which can be recognized by a human, and a coding method thereof.

[0002]

2. Description of the Related Art A bar code or a two-dimensional code has conventionally been used as a technique for representing information by a code printed on paper or the like. Many of these are brightness information (black and white)
It is configured by arranging unit figures having only ones on a plane.

[0003] These barcodes and two-dimensional codes can be easily, accurately and quickly read by a machine using a laser or CCD.

[0004]

Since bar codes and two-dimensional codes are representations of binary data, it is very difficult for a human to read the meaning. Therefore, it is necessary to supplement the meaning by placing characters around, etc., but when the amount of information is large like some barcodes or most two-dimensional codes, this method There is a natural limitation in printing space for printing.

Since bar codes and two-dimensional codes are represented by inorganic arrangement of black and white unit figures, there is no room for design considerations. Therefore, especially when printed on magazines, books, etc., designs that do not conform to the intentions of the author / publisher are included, and this is regarded as a problem as spoiling the aesthetic appearance.

Heretofore, a method of replacing one code with a plurality of codes by using a predetermined operation has been devised (Japanese Patent Laid-Open No. 9-198479). This method merely replaces the offending code with a plurality of codes to prevent the code from being expressed in an undesired pattern, and cannot express a pattern intended by the creator of the code.

Further, a method has been devised in which a signature or a signature image is added to an electronic document and a part of the signature is deformed so that machine-readable information as authentication information is included in the image in a form that is difficult for humans to perceive. (Japanese Unexamined Patent Publication No. Hei 10
-11509). However, since this method requires reference to the original image at the time of decoding and does not have an error correction function, it cannot be expressed as a code printed on paper like a conventional two-dimensional code. Has low portability and reliability.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a code which can be machine-readable by a data processing device, and which can express information meant by the data so that a human can recognize it, and a coding method therefor. It is in. Hereinafter, a code that can be machine-readable by the data processing device and that can express the information that it means so that a human can recognize it is called a representation code.

[0009]

According to a first aspect of the present invention, there is provided a machine readable machine which comprises a plurality of unit figures arranged two-dimensionally and indicates contents to be transmitted by a set of information given to each unit figure. And each unit graphic is represented by two types of feature values related to color, machine-readable information is represented by the one feature value, a design shape is represented by the other feature value, and the machine-readable information is represented by the other feature value. It is a symbolic code characterized by being overlaid on top.

According to a second aspect of the present invention, there is provided a method of encoding a machine-readable code which comprises a plurality of unit figures arranged two-dimensionally and represents contents to be transmitted by a set of information given to each unit figure. In addition, each unit graphic is represented by two kinds of feature amounts related to color, machine-readable information is represented by the one feature amount, a design shape is represented by the other feature amount, and is superimposed on the machine-readable information. In the encoding method.

[0011]

According to the first aspect of the present invention, each cell, which is a unit figure constituting a two-dimensional code, has color information, and two types of feature amounts of the color information are focused on. A two-dimensional code is provided in which a feature is used by a machine to read information, and the other feature is used by a human to recognize a design shape. More specifically, in order to represent information read by a machine (information of a conventional two-dimensional code) (hereinafter referred to as machine read information), one of the feature amounts is discretely changed to a plurality of levels, and a design read by a human. In order to represent shape information, the other feature amount is discretely changed to a plurality of levels. Therefore, it is possible to provide a two-dimensional code which can express an arbitrary design shape while being a two-dimensional code expressing machine-readable information. As a result, even if a two-dimensional code is printed on a printed material such as paper, a large amount of information can be easily read by a camera or a scanner as machine-readable information, and the contents can be easily read by humans. Is obtained.

According to the second aspect of the present invention, each cell which is a unit figure constituting a two-dimensional code is provided with color information, and attention is paid to two kinds of feature amounts of the color information. Is used for reading information, and the other feature is used for human to recognize the design shape.
Provide a method of expressing a dimensional code. More specifically, one feature value is discretely changed to a plurality of levels to represent machine-readable information, and the other feature value is discretely changed to a plurality of levels to represent design shape information read by a human. . Therefore, according to this method, an arbitrary design shape can be represented in a two-dimensional code representing machine-readable information. As a result, even when the two-dimensional code is printed on a printed material such as paper, a large amount of information can be expressed as machine-readable information without obstruction, and the effect that the contents can be easily recognized by humans can be obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.
As a common premise, the code creator prepares an intended design shape in the form of an icon 20 as shown in FIG. 2 in which each cell is expressed by two types of gray levels, white and black. The data area 10 of the symbolic code to be created is divided into a plurality of cells 11, and the number of vertical and horizontal cells in the data area is determined by the icon 2
Each cell 11 is associated with each cell 21 of the icon 20.

In the present embodiment, each cell in the data area is represented by two types of feature amounts relating to colors "brightness" and "hue", and the machine-readable information is represented by one of the feature amounts. Are represented by the other feature amount and are superimposed on the machine-readable information and a coding method thereof. For human beings, the greater the difference in brightness and color, the easier it is to recognize the design shape, and when reading with a machine, the greater the difference in brightness or color, the easier it is to read correctly. .

A description will be given of the selection of a feature quantity relating to color in this embodiment. The color system includes Lab color system and HSB.
There are many color systems such as a color system and an RGB color system. At least one of the elements representing colors in each color system is selected as one type of feature amount related to the color. Here, the description will be made using the Lab color system among a number of color systems. The Lab color system refers to colors L, a, b as shown in FIG.
In the color system represented by the following three elements, L represents brightness, the hue in the circumferential direction around the L axis, and the component ratio (%) of two colors having a complementary color relationship in the normal direction. That is, when the spectral intensities of two complementary colors are I ₁ and I ₂ , a = [(I ₁ −I
₂ ) / (I ₁ + I ₂ )] × 100. The a-axis shows the component ratio difference between magenta and its complementary green color, and the b-axis shows the component ratio difference between yellow and its complementary blue color. Here, La
The feature amount represented by the value L of the b color system is defined as “brightness”, and the feature amount represented by the coordinates (a, b) of an arbitrary point on the ab plane is defined as “hue”. There are two types of feature amounts related to colors in the example. Of course, in the case of the HSB color system, the feature amount represented by the value of B (lightness) and H
A feature amount represented by at least one of the values of (hue) and S (saturation) may be selected and used as two types of feature amounts.

FIG. 14 is a block diagram of an apparatus for implementing the present invention. The data processing device 1 creates a representation code,
The reading device is generally a computing device such as a computer, and is connected to the display device 2, the printing device 3, the image input device 4, the data input device 5, and the external storage device 6, and manages each device. I have. The display device 2 is connected to the data processing device 1 and is generally a display or the like. The printing device 3 is connected to the data processing device 1 and is generally a printer or the like. The image input device 4 is connected to the data processing device 1 and is generally a scanner, a digital camera, or the like. The data input device 5 is connected to the data processing device 1 and is generally a keyboard or the like. The external storage device 6 is connected to the data processing device 1 and is generally a hard disk or the like.

In the first embodiment, machine read information is expressed by using brightness as one characteristic amount, and a design shape is expressed by using hue as the other characteristic amount. That is, in correspondence with the tone of each cell of the icon, each cell on the data area is given a different color tone determined by different points on the ab plane to express the design shape, The machine-readable information is expressed by giving the cell a brightness determined by several different L values. In the first embodiment, the coordinate values (a, b) correspond to (−100, 0),
By giving each cell two types of shades, green and yellow, represented by two points (0, 100), the design shape is expressed, and for each cell, the L value corresponding to a bright color and the dark color are supported. By giving two types of L values, machine read information is represented. FIG. 1 shows an example of the data area of the created code. In this embodiment, since both the brightness and the hue are divided into two layers, “bright” is replaced by “1”,
“Dark” is binarized with “0”, pure green “1”, and pure yellow “0”. Hereinafter, the binarization variable of the brightness is α,
Let the binarization variable of the hue be β. α = 0,1, β = 0,
It is one.

Here, it is important that the difference in brightness can be correctly recognized without being affected by the difference in color when the machine reads the image. Therefore, at the time of code creation, for example, the brightness is set to 2 for each color in the following manner.
Value. As shown in FIG. 4, two L values are determined by changing the brightness value, that is, the L value, for each hue of the point represented by the coordinates (a, b) (here, green 41 and green 4).
2 and yellow 43 and yellow 44 have the same (a, b) coordinates but different L values.) By making the two values of the brightness, that is, the L value common to all the shades (the same L value is given to the green 41 and the yellow 43 and the green 42 and the yellow 44, respectively), the shades are different. Even so, the difference in brightness can be determined. For example, even if a camera capable of capturing only a grayscale image is used, the difference in brightness can be correctly recognized.

FIG. 5 shows a procedure for creating a code according to the first embodiment. This procedure is performed by the data processing device 1. First,
Source information (for example, a character string, a numerical value, an ID, etc.) to be stored as a code is input to the data processing device 1 by the data input device 5 (step 51). The data processing device 1 encodes the input source information into binary values of 0 and 1 (step 52) and adds an error correction code (step 53).
Obtain valuation information. The binarized information is arranged on each cell of the data area (step 54). That is, in the memory of the data processing device 1, an address A = wy * x + F corresponding to the coordinates (x, y) of the data area shown in FIG.
(Where w is the number of cells per row in the data area and F is the offset address), the binarized information is sequentially stored. Thereby, the binarization variable α (x, y) of the brightness of each cell in the output image in which the brightness and the hue are superimposed.
Is determined.

Further, the data processing device 1 converts an icon image formed at a binary level of light and dark shown in FIG. 2 into an image input device in order to determine a design shape of an output image in which brightness and color are superimposed. Input from step 4 (step 55). The icon image may be created by the data input device 1 instead of being input from the image input device 4. That is, the gray value read for each cell of the icon image is binarized into 1 and 0 according to the level, and the binarized data is stored in the memory of the data processing device 1 in the cell coordinates ( x, y) corresponding to address B = w
It is sequentially stored in y + x + G (G is an offset address). Thereby, the design shape of the output diagram is obtained. Next, the binarized data and the tint binarized data are associated (step 56). That is, in the binary data of light and dark stored at the address B, “1” is defined as pure green and “0” is defined as pure yellow, so that the design shape of the output diagram is expressed in shades. Become. As a result, the binarization variable β (x, y) of the color of each cell in the output image in which the brightness and the color are superimposed is determined.

The binarization variable α (x, y) of the brightness obtained in step 54 and the color tone 2 obtained in step 56
The binarized data (α, β) of the output image in which the brightness and the hue are superimposed by rearranging the set of the quantification variables β (x, y) to the address corresponding to the cell coordinates (x, y) Is obtained.

Next, the above α (x, y) and β (x, y)
, R, G, B for driving the printing apparatus 3 using data such as input contrast and output brightness based on
Data is generated (step 57). Then, based on the R, G, B data, the output is output from the printing device 3 (step 58), and as shown in FIG. 1, the output in which the binarized brightness and the binarized color are superimposed. An image is obtained. The binarized brightness is machine-readable information serving as information for the computer, and the binarized hue is a design shape that can be recognized by humans.

In the case where the brightness is binarized by inputting the above-described icon image, a statistical method such as cluster analysis is used based on the distribution of the brightness value obtained for each cell. be able to.

FIG. 6 shows a code reading procedure according to the first embodiment. The symbolic code to be read is the image input device 4
Is read by the data processing device 1. The data processing device 1 cuts out a target data area from the read image of the symbolic code (step 61). Next, the brightness value, that is, the L value of each cell in the data area is obtained (step 62), the brightness is binarized, and the brightness binarization variable α
(X, y) is demodulated (step 63). Also in this binarization, a technique such as cluster analysis can be used for the read brightness value as described above. Further, when an error is detected by the error correction code of the binarized information (step 64), the data error is corrected (step 65). The data obtained as a result is converted into information such as a character string, a numerical value, and an ID, if necessary, and displayed on the display device 2 or output to the external storage device 6 as a file (step 66).

In the icon of FIG. 2, the design is expressed by two gradations. However, the icon of three or more gradations as shown in FIG. A design shape of a symbolic code can be created by associating colors.

Further, by expressing the brightness not in binary but in multiple values, the amount of machine-readable information can be increased.

In the second embodiment, machine read information is expressed by using a color as one characteristic amount, and a design shape is expressed by using brightness as the other characteristic amount. That is, the design shape is expressed by giving each cell in the data area a brightness determined by several different L values in accordance with the gradation of each cell of the icon, and the design shape is expressed. , Ab plane to represent machine-readable information by giving several shades determined by different points.
In the second embodiment, a design shape is expressed by giving two types of L values, an L value corresponding to a bright color and an L value corresponding to a dark color, corresponding to the two types of gradations in FIG. , For each cell, the coordinate values (a, b) are (100, 0),
(0, -100), (-100, 0), (0, 100)
The machine-readable information is expressed by giving four types of shades, magenta, blue, green, and yellow, represented by the four points. FIG. 8 shows an example of the data area of the created code. In this embodiment, the brightness is divided into two layers,
“Bright” is “1” and “dark” is “0” and binarized, the color is divided into four layers, pure magenta is “3”, pure blue is “2”, pure green is “1”, Pure yellow is quaternized as “0”. Hereinafter, the binarization variable of brightness is α, and
Let β be a valuation variable. α = 0,1, β = 0,1,2,3
It is.

Here, when a machine reads, it is important that a difference in color can be correctly recognized without being affected by a difference in brightness. Therefore, at the time of code creation, for example, a color is selected by the following method. FIG.
As shown in (1), the color value, that is, the coordinates (a, b) are determined while the brightness value, that is, the L value is fixed. It is important to determine the coordinates (a, b) so that the distances on the ab plane are as large as possible so that the color layers are easily separated at the time of reading.

FIG. 10 shows a procedure for creating a code according to the second embodiment. First, source information (for example, a character string, a numerical value, or an ID) to be recorded as a code is input to the data processing device 1 by the data input device 5 (step 101). The data processing device 1 converts the input source information into 0, 1, 2, 3
(Using two bits) (step 10
2) Add an error correction code to obtain quaternary information (step 103). The quaternary information is arranged on each cell in the data area (step 104). That is, the address B corresponding to the cell coordinates (x, y) of the data area shown in FIG.
= W · y + x + G, and the quaternary information is sequentially stored. Thus, the quaternary variable β (x, y) of the color of each cell in the output image in which the color and the brightness are superimposed is determined.

Further, the data processing device 1 inputs an icon image formed at a binary level of light and dark as shown in FIG. 2 in order to determine the design shape of the output image in which the hue and the brightness are superimposed. Input from the device 4 (step 105).
The icon image may be created by the data processing device 1 instead of being input from the image input device 4. That is, the gray value read for each cell of the icon image is binarized into 1, 0 according to the level, and the binarized data is stored in the memory of the data processing device 1 in the cell coordinates ( x, y) address A = w
・ They are sequentially stored in y + x + F. Thereby, the design shape of the output diagram is obtained. Next, the binarized data is made to correspond to the binarized data of brightness (step 106). That is, in the binary data of light and dark stored at the address A, “1” is defined as “bright” and “0” is defined as “dark”, so that the design shape of the output diagram is expressed by brightness. It will be. Thereby, the binarization variable α (x, y) of the brightness of each cell in the output image in which the hue and the brightness are superimposed.
Is determined.

The set of the quaternary variable β (x, y) of the color obtained in step 104 and the binarized variable α (x, y) of the brightness obtained in step 106 are represented by the cell coordinates (x , Y)
Is obtained, the multi-valued data of the output image in which the hue and the brightness are superimposed is obtained.

Next, the above α (x, y) and β (x, y)
, R, G, B for driving the printing apparatus 3 using data such as input contrast and output brightness based on
Data is generated (step 107). Then, based on the R, G, and B data, the printing is performed by the printing device 3 (step 108), and as shown in FIG. 8, an output in which the quaternized color and the binarized brightness are superimposed. An image is obtained. The quaternized color is machine-readable information serving as information for a computer, and the binarized brightness is a design shape that can be recognized by humans.

When reading by the machine, the color of the color determined by the coordinates (a, b) is determined using a statistical method such as cluster analysis based on the distribution of the color values obtained for each cell. Perform separation and obtain machine readable information.

FIG. 11 shows a code reading procedure according to the second embodiment. The code to be read is read into the data processing device 1 by the image input device 4. The data processing apparatus 1 cuts out a data area from the image of the read code (step 111). Next, the color of each cell in the data area, that is, the coordinates (a, b) is obtained (step 112), and the obtained color value of each cell is quaternized by the above-described cluster analysis or the like, and the color 4 is obtained. The valuation variable β (x,
y) is demodulated (step 113). When a data error is detected by the error correction code of the quaternary information (step 114), the data error is corrected (step 115). The data obtained as a result is converted into information such as a character string, a numerical value, and an ID, if necessary, and displayed on the display device 2 or output to the external storage device 6 as a file (step 116).

In the second embodiment, the icon prepared by the code creator can be a multi-tone image as shown in FIG. In this case, each gradation of a given image is replaced by several different types of brightness.

In any of the embodiments, it is necessary to cut out a code at the time of reading. For this purpose, it is also effective to arrange a positioning symbol composed of a monochrome cell as described in Japanese Patent Application Laid-Open No. 7-254037 in an area other than the data area. As shown in FIG. 12, positioning symbols 12 are provided at the corners of the data area of the symbolic code. Desirably, three corners are provided. At the time of reading, the read image is binarized in terms of brightness or color and the positioning symbol 12 is detected. Then, the data area of the symbolic code is cut out using the position of the symbol 12 as a clue. After that, the color tone and brightness of each cell are examined in the original multi-tone image. Such a method can be adopted.

In addition to the method of separating brightness or hue using a statistical method at the time of reading, as shown in FIG. 13, a calibration cell 13 is arranged outside the data area of the symbolic code. By referring to this at the time of reading, it is also possible to use it as a reference for layering brightness or hue. In other words, all combinations of brightness and color of the cells appearing in the data area are arranged at a position defined in advance as a series of calibration cells 13. When determining the brightness or hue of the cell in the data area as the machine read information, the distance on the L axis or the distance on the ab plane between the cell to be read and the calibration cell 13 is determined. The distance is calculated, and the calibration cell having the minimum distance is determined. In this method, the brightness or the hue of the read cell is determined based on the predetermined hierarchical index of the brightness or the hierarchical index of the hue of the calibration cell. It is also effective to arrange a plurality of the calibration cells 13 in consideration of the fact that the calibration cells 13 become dirty or noise is generated at the time of reading.

[Brief description of the drawings]

FIG. 1 is a plan view showing a data area of a symbolic code according to a first embodiment.

FIG. 2 is a plan view showing an icon for giving a design shape to the symbolic code so that the meaning of the code can be visually recognized by a human.

FIG. 3 is an explanatory diagram showing a Lab color system.

FIG. 4 is an explanatory diagram showing a relationship between a color hierarchy representing a representation code and a brightness hierarchy.

FIG. 5 is a flowchart showing a processing procedure by the data processing device for creating a symbolic code according to the first embodiment;

FIG. 6 is a flowchart showing a processing procedure by a data processing device for reading a symbolic code according to the first embodiment;

FIG. 7 is a plan view showing icons for giving a design shape in three or more levels of brightness in a symbolic code according to a modification of the present invention.

FIG. 8 is a plan view showing a data area of a symbolic code according to the second embodiment.

FIG. 9 is an explanatory diagram showing a relationship between a hierarchy of brightness and a hierarchy of color in the symbolic code of the second embodiment.

FIG. 10 is a flowchart showing a processing procedure by a data processing device for creating a symbolic code according to the second embodiment.

FIG. 11 is a flowchart showing a processing procedure by a data processing device for reading a symbolic code according to the second embodiment.

FIG. 12 is a plan view showing a symbolic code using a positioning symbol.

FIG. 13 is an explanatory diagram showing a symbolic code using a calibration cell as an index for layering brightness and color when reading machine-readable information of the symbolic code.

FIG. 14 is a block diagram showing an apparatus for implementing the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Data processing device 2 ... Display device 4 ... Image input device 10 ... Data area 11 ... Cell 12 ... Positioning symbol 13 ... Calibration cell 20 ... Icon 21 ... Pixel

Claims (2)

[Claims] 1. A machine-readable code which is composed of a plurality of unit figures arranged two-dimensionally and indicates contents to be transmitted by a set of information given to each unit figure. In addition to being represented by a kind of feature, machine-readable information is represented by the one feature,
A representation code representing a design shape by the other feature amount and superimposed on the machine-readable information. 2. A machine readable code encoding method comprising a plurality of unit figures arranged two-dimensionally and representing contents to be transmitted by a set of information given to each unit figure. Is expressed by two types of feature amounts related to color, machine-readable information is expressed by the one feature amount, and the design shape is expressed by the other feature amount and is superimposed on the machine-readable information. .