JP2022154970A - Code reading device - Google Patents

Abstract

To provide a technique for reading an information code by utilizing gradation of colors of an image acquired from a camera.SOLUTION: A code reading device executes code processing of acquiring an image indicating a specific code from a camera and reading information recorded in the specific code from the image. The specific code is constituted from 3 or more colors in black-white gradation. The specific code includes a first information code having a first pattern and a second information code having a second pattern. The first pattern is a pattern in 2 colors of a first color of 3 or more colors and a second color being the second color of the 3 or more colors and closer to white than the first color. The second pattern is a pattern in 2 colors of a third color of the 3 or more colors and a fourth color being the fourth color of the 3 or more colors and closer to white than both of the second color and the third color.SELECTED DRAWING: Figure 1

Description

The technology disclosed in this specification relates to a code reader for reading information recorded in an information code.

Patent Literature 1 discloses a code reader equipped with a camera capable of capturing an information code (for example, a bar code). The code reader reads the information recorded in the information code from the image showing the information code when the camera captures the information code.

Japanese Patent Application Laid-Open No. 2020-161106

In recent years, the resolution of color gradations in cameras has increased. Code readers may also have cameras with relatively high resolution. The code reader binarizes the image acquired from the camera and reads the information in the barcode represented by the binarized image. High-resolution color gradation is redundant for simple binarization. In the conventional simple binarization method, among high-resolution color gradations, colors other than the two colors (for example, black and white) used for the information code were not used for reading the information code.

This specification provides a technique for reading an information code using color gradation of an image acquired from a camera.

The code reading device disclosed in the present specification includes a camera capable of imaging a specific code, acquires an image showing the specific code from the camera, and reads information recorded in the specific code from the image. a processing execution unit that executes code processing for reading, wherein the specific code is composed of three or more colors between a black-and-white gradation that is a gradation of black and white; A first information code having one pattern and a second information code having a second pattern, wherein the first information code records first information and the second information code records second information, wherein the first pattern is a first color among the three or more colors and a second color among the three or more colors, and the second color closer to the white color than the first color, and the second pattern includes the third color among the three or more colors and the three A two-color pattern of a fourth color among the above colors, the fourth color being closer to the white than both the second color and the third color, and the image wherein the black-and-white gradation is expressed at a predetermined resolution, and the code processing is a first conversion process for converting the image into a first image expressed at a first resolution lower than the predetermined resolution. wherein the first resolution is a resolution obtained by reducing the predetermined resolution centering on a color between the first color and the second color; a second conversion process for converting an image into a second image expressed at a second resolution lower than the predetermined resolution, wherein the second resolution is the predetermined resolution as the third color; converting the first information recorded in the first information code from the second conversion processing, which is a resolution reduced centering on the color between the fourth color and the first image; A first reading process for reading, and a second reading process for reading the second information recorded in the second information code from the second image. Here, the first color may be, for example, the black, and the fourth color may be the white. Also, the specific code may be composed of four or more colors, and the third color may be a color closer to white than the second color.

The particular code read by the code reader described above has a black and white gradation from the first color to the fourth color. For example, assume that a conventional code reader reads a particular code. In this case, since the image of the specific code is simply binarized, from the image after binarization, depending on the contrast ratio between the fourth color and the other colors (that is, the first to third colors) Only the information represented, ie the second information in the second information code, can be read. On the other hand, according to the above configuration, the code reading device displays the image showing the specific code at the first resolution centering on the color between the first color and the second color. The first information recorded in the first information code is read from the first image by changing to one image, and the image showing the specific code is changed to a color between the third color and the fourth color. is changed to a second image represented by a second resolution centered on , and the second information recorded in the second information code is read from the second image. That is, the code reader reduces the predetermined resolution representing the black-and-white gradation to the first resolution and the second resolution, and can read the first information that cannot be read by the conventional code reader. .

Also, the control method of the code reading device, the computer program for the code reading device, and the storage medium storing the computer program are novel and useful.

1 is a conceptual diagram of an embodiment; FIG. 1 is a block diagram of a code reader; FIG. It is a flowchart figure which shows the process which a code reader performs. FIG. 4 is a diagram for explaining the resolution of black-and-white gradation;

(Configuration of code reader 10; FIGS. 1 and 2)
The code reader 10 of this embodiment is a portable device for reading information recorded in an information code (for example, a bar code, a two-dimensional code, a multi-level bar code, etc.). Note that the appearance of the code reading device 10 shown in FIG. 1 is merely an example. For example, the code reading device 10 may have the same appearance as a smartphone, or may be a stationary device. .

The code reader 10 includes an operation section 12 , a display section 14 , a camera 20 and a control section 30 . The operation unit 12 has a plurality of keys. A user can input various instructions to the code reader 10 by operating the operation unit 12 . The display unit 14 is a display for displaying various information. Further, the display unit 14 may function as a touch panel (that is, the operation unit 12) capable of accepting user operations.

Camera 20 includes a light source such as an LED light and a CCD image sensor. The color gradation resolution of the camera 20 is 12 bits. The image acquired from the camera 20 is represented by a 4096-tone color gradation. Note that, in a modified example, the resolution of the camera 20 may be 8 bits, 14 bits, or the like.

The control unit 30 includes a CPU 32 and a memory 34 configured by a nonvolatile memory or the like. The CPU 32 executes various processes according to programs 40 stored in the memory 34 .

The code reader 10 can read not only the information recorded in the conventional bar code 200 but also the information recorded in the special code 100 .

As shown in FIG. 1, the special code 100 consists of four colors: white, light gray, dark gray, and black, between a black and white gradation that is a gradation between black and white. The special code 100 includes an upper bar code 100a and a lower bar code 100b. The upper barcode 100a is a barcode having a two-color pattern of black and dark gray. The lower barcode 100b is a barcode having a two-color pattern of light gray and white. It should be noted that the special code 100 shown in FIG. 1 is schematic.

(Processing of code reader 10; FIG. 3)
Processing executed by the CPU 32 of the code reader 10 according to the program 40 will be described with reference to FIG. The processing in FIG. 3 is processing for reading information recorded in the special code 100 . The processing in FIG. 3 is triggered by the code reading device 10 receiving an instruction to read information in the special code 100 via the operation unit 12 .

In S<b>10 , the CPU 32 activates the camera 20 and causes the camera 20 to capture the special code 100 . Thereby, the CPU 32 acquires an image from the camera 20 . In addition, below, the image acquired from the camera 20 is described as a "captured image." Here, for example, when the captured image includes an image of a special code 100 (hereinafter referred to as a "code image"), the code image is a 12-bit (that is, 4096-gradation) black-and-white gradation as shown in FIG. resolution.

In S20, the CPU 32 converts the captured image into a first image expressed with a lower 8-bit resolution lower than the 12-bit resolution. The lower 8-bit resolution is a resolution obtained by reducing the 12-bit resolution centering on colors between black and dark gray (for example, gradation colors of the 4th bit). As shown in FIG. 4, in the lower 8-bit resolution, the dark gray gradation is closer to the white side than the 4th bit gradation. When the captured image includes the code image, when the image corresponding to the code image in the first image is binarized, the white, light gray, and dark gray portions in the image are converted to white. and black parts in the image are converted to black. That is, the image IM1 of FIG. 1 is obtained by binarizing the first image. The black and white pattern indicated by image IM1 is the same as the black and white pattern of barcode 100a in the upper row.

In S22, the CPU 32 determines whether information can be read from the first image. For example, the CPU 32 determines that information can be read from the first image when a feature representing a pattern of the special code 100 (hereinafter referred to as "code pattern") is detected from the first image. It judges (YES at S22), and proceeds to S24. On the other hand, when the code pattern is not detected from the first image, the CPU 32 determines that information cannot be read from the first image (NO in S22), skips S24, and proceeds to S30. .

In S24, the CPU 32 binarizes the first image. Then, the CPU 32 reads the information recorded in the upper bar code 100a by decoding the binarized image (for example, the image IM1 in FIG. 1). After completing S24, the CPU 32 proceeds to S30.

In S<b>30 , the CPU 32 converts the captured image into a second image represented by a higher 8-bit resolution lower than the 12-bit resolution. The upper 8-bit resolution is a resolution obtained by reducing the 12-bit resolution centering on colors between white and light gray (for example, gradation colors of the 8th bit). As shown in FIG. 4, in the upper 8-bit resolution, the light gray gradation is closer to black than the 8-bit gradation. When the captured image includes the code image, when the image corresponding to the code image in the second image is binarized, the light gray, dark gray, and black portions in the image are converted to black. and the white parts in the image are converted to white. That is, the image IM2 of FIG. 1 is obtained by binarizing the second image. The black and white pattern indicated by image IM2 is the same as the black and white pattern of the lower bar code 100b.

S32 is similar to S22, except that a second image is used. When the CPU 32 determines that information can be read from the second image (YES in S32), the process proceeds to S34. On the other hand, when the CPU 32 determines that it is impossible to read information from the second image (NO in S32), it skips S34 and proceeds to S40.

In S34, the CPU 32 binarizes the second image. Then, the CPU 32 reads the information recorded in the lower bar code 100b by decoding the binarized image (for example, the image IM2 in FIG. 1). After completing S34, the CPU 32 proceeds to S40.

In S40, the CPU 32 outputs the reading result of the special code 100. FIG. If the special code 100 is read successfully, the reading result contains two pieces of information recorded in the special code 100 . If the reading of the special code 100 fails, the reading result will contain information indicating the reading failure. For example, the CPU 32 outputs the reading result by displaying the reading result on the display unit 14 . Alternatively, the CPU 32 may output the reading result by transmitting the reading result to an external device (for example, a server). Also, in another modification, the CPU 32 may output a voice indicating the reading result. When S40 ends, the process of FIG. 3 ends.

(Effect of this embodiment)
For example, assume that a conventional code reader reads a special code 100 . In this case, since the image of the special code 100 is simply binarized, the binarized image is represented by the contrast ratio between white and other colors (i.e., light gray, dark gray, and black). Only the information on the lower bar code 100b can be read. On the other hand, according to the configuration of this embodiment, the code reader 10 changes the code image to the first image (see image IM1 in FIG. 1) represented by the lower 8-bit resolution, While reading the information in the upper bar code 100a from the image, the code image is changed to the second image (see image IM2 in FIG. 1) represented by the higher 8-bit resolution, and the lower bar code is read from the second image. Read the information in 100b. That is, the code reader 10 reduces the 12-bit resolution to a lower 8-bit resolution and a higher 8-bit resolution, and can read the information in the upper bar code 100a that could not be read by the conventional code reader. can.

For example, it is assumed that a special code 100 is used at a store. For example, the upper barcode 100a records information such as the expiration date of the product in the store, and the lower barcode 100b records an identification code (for example, a POS code) for identifying the product in the store. . By reading the special code 100 using the code reader 10, the manager of the store can obtain not only the identification code but also information such as the expiration date. On the other hand, a store clerk can obtain an identification code by reading the special code 100 using a conventional code reader (for example, a scanner connected to a POS cash register). For example, a comparative example in which an information code used by a salesperson is prepared in addition to an information code used by an administrator is assumed. In this comparative example, two information codes are displayed at separate locations for one product. On the other hand, according to the configuration of this embodiment, it is sufficient to display one special code 100 at one place for one product. By using one special code 100, a worker can obtain different information depending on the position of the worker handling the product.

(correspondence relationship)
The special code 100, the upper bar code 100a, and the lower bar code 100b are examples of the "specific code,""first information code," and "second information code," respectively. Black, dark gray, light gray, and white are examples of "first color,""secondcolor,""thirdcolor," and "fourth color," respectively. The code reader 10, the camera 20, and the control unit 30 are examples of the "code reader,""camera," and "processing execution unit," respectively. The 12-bit resolution, the lower 8-bit resolution, and the upper 8-bit resolution are examples of the "predetermined resolution,""firstresolution," and "second resolution," respectively. S20, S24, S30, and S34 in FIG. 3 are examples of "first conversion processing,""first reading processing,""second conversion processing," and "second reading processing," respectively.

Specific examples of the technology disclosed in this specification have been described above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. For example, the following modifications may be adopted.

(Modification 1) The "first information code (and second information code)" is not limited to a barcode, and may be, for example, a multi-stage barcode, a two-dimensional code, or the like.

(Modification 2) In the above embodiment, the special code 100 consists of four colors: white, light gray, dark gray and black. Alternatively, special code 100 may consist of four colors: lightest grey, light grey, dark grey, and darkest grey. In other words, the special code 100 may consist of any four colors between black and white gradations. In this modification, the darkest gray and lightest gray are examples of the "first color" and the "fourth color", respectively.

(Modification 3) In the above embodiment, the captured image is converted into the first image represented by the lower 8-bit resolution (S20 in FIG. 3). Instead of this, the captured image is represented at a resolution in a range between arbitrary gradations on the black side (for example, a range from the 7th bit gradation to the 2nd bit gradation, and a range from the 9th bit gradation to the 2nd bit gradation). image. In this modified example, the resolution in the range between arbitrary gradations on the black side is an example of the “first resolution”.

(Modification 4) In the above embodiment, the special code 100 consists of four colors: white, light gray, dark gray and black. Alternatively, special code 100 may consist of three colors: white, gray and black. In this modified example, gray is an example of "second color and third color". Also, in other variations, the special code 100 may consist of more than five colors. Generally speaking, the "specific code" may consist of three or more colors.

The technical elements described in this specification or in the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims as of the filing. In addition, the techniques exemplified in this specification or drawings achieve multiple purposes at the same time, and achieving one of them has technical utility in itself.

10: Code reader 12: Operation unit 14: Display unit 20: Camera 30: Control unit 32: CPU
34: Memory 40: Program 100: Special code 100a: Upper bar code 100b: Lower bar code IM1, IM2: Image after binarization

Claims (3)

a camera capable of imaging a specific code;
a processing execution unit that acquires an image showing the specific code from the camera and executes code processing that reads information recorded in the specific code from the image;
with
the specific code is composed of three or more colors between a black and white gradation that is a gradation of black and white;
The specific code includes a first information code having a first pattern and a second information code having a second pattern,
The first information code records first information,
The second information code records second information,
The first pattern is a first color among the three or more colors and a second color among the three or more colors, and is closer to the white than the first color. a two-color pattern of the second color and
The second pattern is a third color among the three or more colors and a fourth color among the three or more colors, wherein the second color and the third color A two-color pattern of the fourth color that is closer to the white than both of the
In the image, the black-and-white gradation is expressed at a predetermined resolution,
The code processing is
a first conversion process for converting the image into a first image expressed at a first resolution lower than the predetermined resolution, wherein the first resolution converts the predetermined resolution to the first color; the first conversion process being a reduced resolution centered on a color between and the second color;
a second conversion process for converting the image into a second image expressed at a second resolution lower than the predetermined resolution, wherein the second resolution converts the predetermined resolution to the third color; the second conversion process being a reduced resolution centered on a color between and the fourth color;
a first reading process of reading the first information recorded in the first information code from the first image;
a second reading process of reading the second information recorded in the second information code from the second image;
A code reader. the first color is the black;
2. The code reader according to claim 1, wherein said fourth color is said white. The specific code is composed of four or more colors,
3. The code reader according to claim 2, wherein said third color is closer to said white than said second color.

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