CN110610219B - A color ring two-dimensional code and its generation and decoding method - Google Patents

Abstract

The invention discloses a color annular two-dimensional code and a method for generating and decoding the same. The two-dimensional code includes a black and white positioning area, and the positioning area includes a solid circle and a first ring and a second ring located outside the solid circle. Two rings, the first ring and the second ring are two concentric rings; for the colored data area, the data area is a third ring concentric with the positioning area, the positioning The area is located inside the third ring, and the third ring is divided into a plurality of data blocks. The two-dimensional code generation method is as follows: converting a data stream into a quaternary number, and coloring a plurality of data blocks according to the corresponding relationship between the quaternary number and the color. When decoding, first find the center of the positioning area, and then scan and decode in polar coordinates. By adopting the color coding and the decoding method based on scanning, the new two-dimensional code can effectively improve the anti-distortion capability of the image while reaching the basic information capacity.

Description

A color ring two-dimensional code and its generation and decoding method

technical field

The invention relates to the field of two-dimensional codes, in particular to a color annular two-dimensional code and a method for generating and decoding the same.

Background technique

In recent years, the application of QR codes has become more and more extensive, especially in the fields of mobile payment and online social networking. Due to its large information capacity and fast identification, it has been rapidly popularized in people's daily life. Although two-dimensional codes have been widely promoted, in many scenarios, existing two-dimensional codes still have certain limitations. The most prominent one is the lack of anti-image distortion capabilities of two-dimensional codes. In fact, the correct recognition of the matrix two-dimensional code represented by QR Code is based on a foundation: the two-dimensional code is printed on a flat surface. If the plane on which the QR code is located is convex or concave, such as when the QR code is printed on a sphere, the recognition rate of the QR code will drop significantly. For curved surfaces such as cylinders, cones, and even non-rigid surfaces such as fabrics, the recognition ability of QR codes is very limited. The Chinese invention patent with the announcement number CN103793735A proposes a new circular two-dimensional barcode and its encoding and decoding method to improve the anti-image distortion ability of the two-dimensional code. However, the two-dimensional code uses a ring as the data unit, and the data density is very low. At the same time, the data is encoded by different grayscale values, which requires high precision of the two-dimensional code reading device, so the practical application of the two-dimensional code is limited. Therefore, the application of two-dimensional codes at this stage mainly focuses on the identification of flat surfaces.

With the development of the Internet of Things, the demand for the identification of two-dimensional codes on various objects is increasing. The low-cost and high-information characteristics of two-dimensional codes make them have great advantages over RFID chips. Therefore, if the anti-image distortion capability of the two-dimensional code can be greatly improved, the application of the two-dimensional code will be further expanded.

SUMMARY OF THE INVENTION

Aiming at the problems existing in the above-mentioned prior art, the present invention proposes a color annular two-dimensional code and a method for generating and decoding the same. By adopting color coding and a new decoding method, the basic information capacity can be achieved, and the image quality can be effectively improved. Distortion resistance.

In order to solve the above technical problems, the present invention is achieved through the following technical solutions.

According to a first aspect of the present invention, there is provided a color ring two-dimensional code, the two-dimensional code comprising:

A black and white positioning area, the positioning area includes a solid circle and a first ring and a second ring located outside the solid circle, and the first ring and the second ring are two concentric circles ring;

A colored data area, the data area is a third circular ring concentric with the positioning area, the positioning area is located inside the third circular ring, and the third circular ring is divided into a plurality of data blocks.

Preferably, the positioning area, wherein:

The solid circle is black, the first ring is white, the second ring is black, and the outer side of the solid circle is sequentially connected to the first and second rings, which are white and one black. ;or

The solid circle is white, the first ring is black, the second ring is white, and the outer side of the solid circle is followed by a black and a white first and second rings. .

Preferably, the ring widths of the first ring and the second ring are the same. Further, the ring width of the first ring and the second ring is 1/3 of the diameter of the solid circle.

Preferably, the third ring is a ring with multiple equal angles, forming a plurality of equal data blocks, wherein one of the data blocks is white as the starting point of data reading, and the other data blocks are They are respectively coded with four colors of red, green, blue and yellow, and are respectively coded as 0, 1, 2 and 3, and the adjacent data blocks have different colors.

Preferably, the third ring is a ring with an angle bisected by 16, and the inner diameter is equal to the outer diameter of the second ring, and the ring width is greater than or equal to 1/3 of the diameter of the solid circle.

According to a second aspect of the present invention, there is provided a method for generating a color circular two-dimensional code, the method: converting a data stream into a quaternary number, and skipping the same result of adjacent quaternary bytes, according to the four There is a corresponding relationship between the base number and the color, and the multiple data blocks in the third circle of the data area are colored.

According to a third aspect of the present invention, there is provided a decoding method for a color ring two-dimensional code, comprising:

S1: Convert the color pixels of the original color ring QR code image, when the solid circle in the positioning area is black, the color pixels are converted to white; when the solid circle in the positioning area is white, the color pixels are converted to black;

S2: Scan the QR code image processed by S1 to find the center of the positioning area;

S3: Taking the center of the positioning area as the coordinate origin, convert the original color ring QR code image to the polar coordinate system;

S4: Scan along the r-axis of the polar coordinate system to find the data area, and scan the decoded data area along the φ-axis of the polar coordinate system.

Preferably, before S1, the method further includes performing white balance processing on the original color circular two-dimensional code picture.

Preferably, after S1, the method further includes performing grayscale, binarization, and Gaussian filtering on the image in sequence.

Preferably, in S3, the scanning along the r-axis of the polar coordinate system to find the data area means that when each row of pixels is scanned, the first color pixel encountered is identified as the pixel sampling point of the data area.

Preferably, the scanning of the decoded data area along the φ axis of the polar coordinate system refers to identifying the color of the pixel sampling points of each row along the φ axis of the polar coordinate system, and when a color jump is encountered, it is determined that a new pixel is reached. data block.

Compared with the prior art, the advantages of the present invention are:

The above-mentioned color ring two-dimensional code of the present invention adopts color coding, and the information capacity of the new two-dimensional code is improved compared with the traditional ring two-dimensional code.

The above-mentioned decoding method of the color ring two-dimensional code of the present invention can improve the anti-image distortion ability of the two-dimensional code by using the scanning-based decoding method, and can deal with barrel distortion, pincushion distortion, perspective distortion and printing on irregular geometry. distortion, there is a better decoding effect.

Description of drawings

Embodiments of the present invention are further described below in conjunction with the accompanying drawings:

1 is a structural diagram of a color ring two-dimensional code according to an embodiment of the present invention;

Fig. 2 is the decoding flow chart of the color annular two-dimensional code according to an embodiment of the present invention;

Fig. 3 is a decoding flow chart of a color ring two-dimensional code according to a preferred embodiment of the present invention;

4 is a two-dimensional code image in a polar coordinate system according to a preferred embodiment of the present invention;

5 is a structural diagram of a color ring two-dimensional code according to another preferred embodiment of the present invention;

Label description: 1-solid circle, 2-first circle, 3-second circle, 4-third circle, 5-data block, 501-white data block, 502-black data block.

Detailed ways

The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

Referring to Figure 1, it is a schematic diagram of a colored annular two-dimensional code in an embodiment of the present invention. The colored annular two-dimensional code shown in the figure includes: a black and white positioning area and a colored data area, and the positioning area includes a solid circle 1 The first ring 2 and the second ring 3 are located outside the solid circle 1. The first ring 2 and the second ring 3 are two concentric rings; the data area is a third ring that is concentric with the positioning area 4. The positioning area is located inside the third circular ring 4 , and the third circular ring 4 is divided into a plurality of data blocks 5 .

In the embodiment shown in FIG. 1 , the solid circle 1 of the positioning area is black, the first ring 2 is white, the second ring 3 is black, and the outer side of the solid circle 1 is followed by a white and a black first ring 2. The second ring 3, that is, the black solid circle 1 is located at the innermost position, then the first ring 2 is covered outside the black solid circle 1, and the second ring 3 is covered outside the first ring 2. In a preferred embodiment, the ring widths of the first ring 2 and the second ring 3 are the same, and the ring width of the first ring 2 and the second ring 3 is 1/3 of the diameter of the solid circle 1 . The third ring 4 is sheathed outside the second ring 3, and the solid circle 1 and the three rings are concentrically arranged. In the embodiment shown in FIG. 1 , the third ring 4 is a ring divided by 16 equal angles, forming 16 equal data blocks 5, one of which is a white data block 501, and the white data block 501 is read as data The other 15 data blocks 5 are coded with four colors of red, green, blue and yellow, which are respectively coded as 0, 1, 2 and 3, and the adjacent data blocks 5 have different colors.

In the above embodiment, a ring with 16 equal parts is used. In other embodiments, it can also be other equal parts. Generally, the equal parts are divided into multiples of 4. The more equal parts, the greater the data density. The higher the resolution requirement is; the fewer the equal divisions, the lower the resolution requirement for the scanning device, but the data density will also be lower. In the above-mentioned embodiment, it is preferably divided into 16 equal parts, and the information capacity is of the order of 10 ⁷ at this time, which can ensure that the data density is similar to the data density of several traditional small-sized two-dimensional codes. For example, the data volume of Micro QR Code under the same size is 10 ⁵ The DataMatrix is 10 ⁶ , that is, the smallest equal division that guarantees the data density. Similarly, in other embodiments, other colors can also be used. The more colors are used, the higher the resolution requirements of the device are. Therefore, in order to achieve basic information capacity, the above embodiment preferably uses four color codes. Further, the color of a pixel is represented by a ternary number composed of three RGB channels. When identifying a color, it is usually determined according to the range of the ternary number of the color. For example, it is recognized as red within the range of (255,0,0). When the combination of red, green, blue, and yellow is used, the decoding does not need to involve the specific range of the data. It only needs to compare the relative size of the ternary to determine which of the four colors is. For example, the value of the red channel (the first number) is much larger than the value of the green channel (the second number) and the value of the blue channel (the third number), it is considered to be red, green and blue are the same, and yellow is blue The complementary color of the color, the first number and the second number are close in value, far greater than the third number, that is, it is judged as yellow. The decoding method designed in this way is simpler and more stable. Therefore, using the four colors of red, green, blue and yellow in the above embodiment can increase the data volume of the two-dimensional code to the level of the existing common small-sized two-dimensional code, and at the same time has the highest stability.

In a preferred embodiment, the third ring 4 is a ring bisected by 16 angles, and the inner diameter is equal to the outer diameter of the second ring 3 , and the ring width is greater than or equal to 1/3 of the diameter of the solid circle 1 .

In the above embodiment, the diameter ratio of the solid circle and the ring of the two-dimensional code is 1:1:3:1:1. Of course, in other embodiments, it can also be other ratios, such as 1:1:4: 1:1 is also possible, but the size of the positioning area will be larger. A diameter ratio of 1:1:3:1:1 is a more preferred ratio.

In another preferred embodiment of the present invention, a method for generating a color circular two-dimensional code is provided. Specifically, a circular two-dimensional code template is first generated, including a black and white positioning area and a color data area. The specific structure is implemented as above. The colored circular QR code in the example. Then convert the data, take the data 410720541 as an example, first convert it into a quaternary number 120132301210131, check that no adjacent bytes are the same, press 0, 1, 2, 3 to correspond to red, green, blue, yellow, respectively, The obtained color sequence of the data area is "green blue red green yellow blue yellow red green blue green red green yellow green", after the white data block 501 is colored counterclockwise according to the color sequence.

In another embodiment of the present invention, a decoding method for the above-mentioned color ring two-dimensional code is provided. Referring to Figure 2, the decoding method can be performed as follows:

S1: Convert the color pixels of the original color ring QR code image to white;

S2: Scan the QR code image processed by S1 to find the center of the positioning area; since the two rings in the positioning area are concentric with the solid circle, the center of the positioning area and the solid circle are the same; scan each line during positioning Pixel, if the color ratio of the pixel is black:white:black:white:black=1:1:3:1:1, it is considered as the positioning area.

S3: Take the center of the positioning area obtained by S2 as the coordinate origin, and convert the original color ring QR code image to the polar coordinate system;

S4: Scan along the r-axis of the polar coordinate system to find the data area, and scan the decoded data area along the φ-axis of the polar coordinate system; among them: Scanning along the r-axis to find the data area refers to the first color encountered when scanning each row of pixels. The pixel is identified as the pixel sampling point of the data area; the scanning and decoding data area refers to identifying the color of the pixel sampling point of each row along the φ axis of the polar coordinate, and it is determined that a new data block 5 is reached when the color jumps.

After reading the color of each data block 5 in the data area in sequence starting from the white data block 501, the quaternary data can be obtained according to the corresponding relationship between the color and the quaternary number, and then converted into a decimal number, that is, Raw data is available.

Figure 4 is a two-dimensional code image in polar coordinate system, the horizontal axis is the r axis, the vertical axis is the phi axis, and the pixel color order of each row is black, white, black, color (or white, only in the white data block. Several lines are white, the last lines in the figure), other colors (because there may be various colors around the QR code, which are represented by other colors here), the first color pixel encountered by the scan is used as the pixel sampling of the data area . In practice, a setting is added to distinguish the white pixels in the data area from the white pixels in the second ring. When the white pixel is encountered for the second time, it is considered as the white pixel of the data block. For example, the last few lines, the color order is Black, white, black, white, the second white pixel is the pixel of the data block.

In another preferred embodiment of the present invention, a decoding method for the above-mentioned color ring two-dimensional code is provided. Referring to Figure 3, the decoding method can be performed as follows:

S1: Perform image preprocessing on the color ring QR code image; image preprocessing includes white balance, which can remove the influence of light on image color;

S2: Convert the color pixels of the two-dimensional code image preprocessed by S1 to white; further, after converting to white, grayscale, binarization, and Gaussian filtering of the image can be performed in turn; grayscale And binarization is to facilitate subsequent positioning operations, and Gaussian filtering is to eliminate noise in some images;

S3: Scan the QR code image processed by S2 to find the center of the positioning area;

S4: Take the center of the positioning area obtained in S3 as the coordinate origin, and convert the original color ring QR code image to the polar coordinate system;

S5: Scan along the r-axis of the polar coordinate system to find the data area, and scan the decoded data area along the φ-axis of the polar coordinate system; this step is the same as the embodiment shown in FIG. 2 and will not be repeated.

5, it is a schematic diagram of a color ring two-dimensional code in another preferred embodiment of the present invention, including: a black and white positioning area and a colored data area, and the positioning area includes a solid circle 1 located outside the solid circle 1. The first ring 2, the second ring 3, the first ring 2 and the second ring 3 are two concentric rings; the data area is a third ring 4 concentric with the positioning area, and the positioning area is located in the third ring. Inside the ring 4 , a plurality of data blocks 5 are divided on the third ring 4 . The difference from Fig. 1 is: the solid circle 1 of the positioning area is white, the first ring 2 is black, the second ring 3 is white, and the outer side of the solid circle 1 is followed by a black and a white first ring. 2. The second ring 3, that is, the white solid circle 1 is located in the innermost, then the black first ring 2 is covered outside the white solid circle 1, and the white second ring 3 is covered in the black first ring 2 outside. The third ring 4 is a ring divided by 16 equal angles, forming 16 equal data blocks 5, one of which is a black data block 502, and the black data block 502 is used as the starting point of data reading, and the other 15 data blocks 5 They are coded with four colors of red, green, blue and yellow respectively, which are coded as 0, 1, 2 and 3 respectively, and the adjacent data blocks 5 have different colors. Other settings are the same as those in the embodiment shown in FIG. 1 , and will not be described again.

Corresponding to the color ring two-dimensional code shown in Figure 5, a decoding method for the color ring two-dimensional code is provided, including:

S1: Preprocess the color ring QR code image with white balance. The white balance is to remove the influence of light on the color of the image;

S2: Convert the color pixels of the two-dimensional code image preprocessed by S1 to black; further, after converting to black, grayscale, binarization, and Gaussian filtering of the image can be performed in turn; grayscale And binarization is to facilitate subsequent positioning operations, and Gaussian filtering is to eliminate noise in some images;

S3: Scan the QR code image processed by S2 to find the center of the positioning area;

S4: Take the center of the positioning area obtained in S3 as the coordinate origin, and convert the original color ring QR code image to the polar coordinate system;

S5: Scan along the r-axis of the polar coordinate system to find the data area, and scan the decoded data area along the φ-axis of the polar coordinate system; this step is the same as the embodiment shown in FIG. 2 .

Parts not described in detail above can be implemented with reference to the technologies in the embodiments shown in FIGS. 1-3 , which are easy to implement for those skilled in the art and will not be repeated here.

The two-dimensional code data area proposed by the above embodiments of the present invention is only a circular ring, and the data area is divided by dividing the circular ring equally, which improves the data density. The precision requirements for the equipment are lower. In the background art, the two-dimensional code data area of CN103793735A needs multiple rings, and the outermost layer needs two rings to separate the pixel interference around the two-dimensional code, while the two-dimensional code of the present invention only needs one ring, and the color The operation of turning white or black allows the data area to be reused as a static area during positioning, which functions to separate pixel interference around the two-dimensional code without adding two more rings, which further improves the data density of the two-dimensional code. For example, the maximum data size of the above-mentioned two-dimensional code of the present invention is about 2*10 ⁷ . Under the same other conditions, the size of the two-dimensional code of CN103793735A with the same data amount is 19.75 of the two-dimensional code of the present invention. times.

To sum up the above embodiments of the present invention, by using color coding and scanning-based decoding methods, the new two-dimensional code can effectively improve the anti-distortion capability of the image while achieving the basic information capacity.

Only preferred embodiments of the present invention are disclosed herein, and the present specification selects and specifically describes these embodiments to better explain the principles and practical applications of the present invention, rather than limiting the present invention. Any modifications and changes made by those skilled in the art within the scope of the description should fall within the protection scope of the present invention.

Claims (10)

1. A colored annular two-dimensional code which characterized in that: the two-dimensional code includes:

the positioning area comprises a solid circle, a first circular ring and a second circular ring, wherein the first circular ring and the second circular ring are positioned outside the solid circle, and the first circular ring and the second circular ring are two concentric circular rings;

the colored data area is a third circular ring concentric with the positioning area, the positioning area is positioned on the inner side of the third circular ring, a plurality of data blocks are divided on the third circular ring, and the colors of the adjacent data blocks are different;

wherein:

the decoding method of the two-dimensional code comprises the following steps:

s1: color conversion is carried out on color pixels of the original color annular two-dimensional code picture, and when the solid circle of the positioning area is black, the color pixels are converted into white; when the solid circle of the positioning area is white, the color pixel is converted into black;

s2: scanning the two-dimensional code picture processed by the S1 to find the center of the positioning area;

s3: converting the color two-dimensional code picture into a polar coordinate system by taking the center of the positioning area as the origin of coordinates;

s4: and scanning along the r axis of the polar coordinate system to find a data area, and scanning along the phi axis of the polar coordinate system to decode the data area.

2. The color annular two-dimensional code according to claim 1, wherein: the positioning region, wherein:

the solid circle is black, the first ring is white, the second ring is black, and the first ring and the second ring which are white and black are sequentially connected to the outer side of the solid circle; or

The solid circle is white, the first ring is black, the second ring is white, and the outer side of the solid circle is sequentially connected with the first ring and the second ring which are black and white.

3. The color annular two-dimensional code according to claim 2, wherein: the widths of the first circular ring and the second circular ring are the same.

4. The color annular two-dimensional code according to claim 2, wherein: the ring width of the first ring and the second ring is 1/3 of the diameter of the solid circle.

5. The color annular two-dimensional code according to claim 1, wherein: the third ring is a ring with multiple equal angles, and a plurality of equal data blocks are formed, wherein one data block is white and serves as a starting point of data reading, and the other data blocks are respectively coded by four colors of red, green, blue and yellow, and are respectively coded as 0, 1, 2 and 3.

6. The color annular two-dimensional code according to claim 5, wherein: the third ring is a ring with an angle 16 equal to the outer diameter of the second ring, and the width of the third ring is greater than or equal to 1/3 the diameter of the solid circle.

7. A method for generating a color annular two-dimensional code according to any one of claims 1-6, wherein: and converting the data stream into a quad number, skipping the result that adjacent quad bytes are the same, and coloring a plurality of data blocks in a third ring of the data area according to the corresponding relation between the quad number and the color.

8. A method for decoding a color annular two-dimensional code according to any one of claims 1 to 6, characterized in that: the method further includes, before S1, white balancing the original color annular two-dimensional code picture.

9. The method for decoding color annular two-dimensional code according to claim 8, wherein: after S1, the method further includes performing graying, binarization, and gaussian filtering on the image in sequence.

10. The method for decoding color annular two-dimensional code according to claim 8, wherein: in the step S3, the first step,

the step of scanning along the r axis of the polar coordinate system to find the data area means that when each line of pixels is scanned, the first color pixel encountered is regarded as the pixel sampling point of the data area;

the step of scanning the decoded data area along the phi axis of the polar coordinate system refers to identifying the color of the pixel sampling point of each row along the phi axis of the polar coordinate system, and when color jump occurs, the new data block is judged to arrive.

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