CN110610219A - A color circular two-dimensional code and its generation and decoding method - Google Patents

Abstract

The invention discloses a color circular 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; the colored data area, the data area is a third ring concentric with the positioning area, the positioning The zone is located inside the third ring, and the third ring is divided into multiple data blocks. The method for generating the two-dimensional code is as follows: converting the 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. The invention adopts the color coding and scanning-based decoding method, and the new two-dimensional code can effectively improve the anti-distortion ability of the image while reaching the basic information capacity.

Description

A color circular 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 circular 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 widespread, 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 promoted on a large scale, in many scenarios, existing two-dimensional codes still have certain limitations, the most prominent being the insufficient ability of two-dimensional codes to resist image distortion. In fact, the correct recognition of the matrix-type two-dimensional code represented by QR Code is based on one foundation: the two-dimensional code is printed on a flat surface. If the plane where the QR code is located is raised or depressed, 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 two-dimensional codes is very limited. The Chinese invention patent with the notification number CN103793735A proposes a new circular two-dimensional barcode and its encoding and decoding method to improve the two-dimensional code's ability to resist image distortion. However, the two-dimensional code uses a circle as the data unit, and the data density is very low. At the same time, the data is encoded by different gray values, which requires high precision for the two-dimensional code reading equipment, 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 on 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 content of two-dimensional codes make them have greater advantages over RFID chips. Therefore, if the ability to resist image distortion of the two-dimensional code can be greatly improved, the application of the two-dimensional code will be further expanded.

Contents of the invention

Aiming at the problems existing in the above-mentioned prior art, the present invention proposes a color ring-shaped two-dimensional code and its generation and decoding method, adopts color coding and a new decoding method, and can effectively improve the image quality while achieving the basic information capacity. Anti-distortion ability.

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 circular 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 outside the solid circle, the first ring and the second ring are two concentric circles ring;

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

Preferably, the positioning area, wherein:

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

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

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 circular ring is a circular ring with multi-divided angles, forming a plurality of equal data blocks, wherein one of the data blocks is white as the starting point for data reading, and the other data blocks are white. The four colors of red, green, blue and yellow 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 of 16 equal parts, 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, a method for generating a colored circular two-dimensional code is provided, the method: converting the data stream into a quaternary number, and skipping the same result of adjacent quaternary bytes, according to the quaternary The corresponding relationship between the base number and the color, color the multiple data blocks in the third ring of the data area.

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

S1: Color-convert the color pixels of the original color circular 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 picture processed by S1 to find the center of the positioning area;

S3: Taking the center of the positioning area as the coordinate origin, transform the original color circular QR code image into the polar coordinate system;

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

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 sequentially performing grayscale, binarization, and Gaussian filtering on the image.

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 to reach a new data block.

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

The above-mentioned colored circular 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 circular two-dimensional code.

The decoding method of the above-mentioned color ring-shaped two-dimensional code of the present invention can improve the anti-image distortion ability of the two-dimensional code by adopting the decoding method based on scanning, and it can cause distortion in dealing with barrel distortion, pincushion distortion, perspective distortion and printing on irregular geometry. Distortion, have a better decoding effect.

Description of drawings

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

Fig. 1 is a structural diagram of a colored circular two-dimensional code according to an embodiment of the present invention;

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

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

Fig. 4 is a two-dimensional code image under the polar coordinate system of a preferred embodiment of the present invention;

Fig. 5 is a structural diagram of a colored circular two-dimensional code of another preferred embodiment of the present invention;

Description of symbols: 1-solid circle, 2-first ring, 3-second ring, 4-third ring, 5-data block, 501-white data block, 502-black data block.

Detailed ways

The present invention will be described in detail below in conjunction with 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 those skilled in the art can make several modifications and improvements without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

Referring to Fig. 1, it is a schematic diagram of a colored circular two-dimensional code in an embodiment of the present invention. The colored circular 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 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 concentric with the positioning area 4. The positioning area is located inside the third ring 4, and the third ring 4 is divided into multiple data blocks 5.

In the embodiment shown in Figure 1, the solid circle 1 of the positioning area is black, the first ring 2 is white, and the second ring 3 is black, and the outer side of the solid circle 1 is sequentially connected with a white and a black first ring 2. The second ring 3, that is, the black solid circle 1 is located at the innermost, 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 widths of the first ring 2 and the second ring 3 are 1/3 of the diameter of the solid circle 1 . The third ring 4 is wrapped around the second ring 3, and the solid circle 1 and the three rings are concentrically arranged. In the embodiment shown in Figure 1, the third ring 4 is a ring with an angle of 16 equal parts, 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 in four colors: red, green, blue, and yellow, and coded as 0, 1, 2, and 3 respectively, and adjacent data blocks 5 have different colors.

In the above embodiment, a ring with 16 equal divisions is used. In other embodiments, other equal divisions can also be used. Generally, the equal division is a multiple of 4. The more equal divisions, the greater the data density. The higher the resolution requirement; the fewer the number of divisions, the lower the resolution requirement for the scanning device, but the data density will also be lower. In the above embodiment, 16 equal divisions are preferred. At this time, the information capacity is on the order of 10 ⁷ , which can ensure that the data density is similar to that 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 , which is the minimum 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 requirement of the device is. Therefore, in order to achieve the basic information capacity, the above embodiment is preferably coded with four colors. 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, the range of (255,0,0) is identified as red. When the four-color combination of red, green, blue, and yellow is used, the decoding does not need to involve the specific range of the data, and only needs to compare the relative size of the ternary numbers to determine which of the four colors it is. For example, the value of the red channel (the first number) is much greater than the value of the green channel (the second number) and the value of the blue channel (the third number), it is considered red, green and blue are the same, yellow is blue The complementary color of the color, the value of the first number is close to the second number, and far greater than the third number, that is, it is judged as yellow. The decoding method designed in this way is more concise 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-size two-dimensional code, and at the same time have the highest stability.

In a preferred embodiment, the third ring 4 is a ring with an angle 16 equally divided, 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 embodiments, 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 preferred ratio.

In another preferred embodiment of the present invention, a method for generating a colored circular two-dimensional code is provided, specifically: first generate a circular two-dimensional code template, including a black and white positioning area and a colored data area, and 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 4-ary number 120132301210131, check and find that there are no adjacent bytes that are the same, press 0, 1, 2, 3 to correspond to red, green, blue, and yellow respectively, The color sequence of the obtained data area is "green blue red green yellow blue yellow red green blue green red green yellow green" and the white data block 501 is colored counterclockwise according to the color sequence.

In another embodiment of the present invention, a method for decoding the above-mentioned colored circular two-dimensional code is provided. Referring to Fig. 2, the decoding method can be carried out as follows:

S1: Convert the color pixels of the original color circular QR code picture to white;

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

S3: Taking the center of the positioning area obtained in S2 as the coordinate origin, transforming the original color circular two-dimensional code image into the polar coordinate system;

S4: Scan along the r-axis of the polar coordinate system to find the data area, and scan along the φ-axis of the polar coordinate system to scan the decoded data area; where: scanning along the r-axis to find the data area refers to the first color encountered when scanning each row of pixels Pixels are identified as pixel sampling points in the data area; scanning and decoding the data area refers to identifying the color of the pixel sampling points in each row along the φ axis of the polar coordinates, and when a color jump occurs, it is determined to reach a new data block 5 .

After reading the color of each data block 5 in the data area sequentially from the white data block 501, the 4-ary data can be obtained according to the corresponding relationship between the color and the 4-ary number, and then converted into a 10-ary number, that is Raw data are available.

Figure 4 is a two-dimensional code image in the polar coordinate system. The horizontal axis is the r axis, and the vertical axis is the φ axis. The order of pixel colors in each row is black, white, black, and color (or white, only in the white data block. A few lines are white, the last few lines in the picture), other colors (because there may be various colors around the QR code, other colors are used here instead), the first color pixel encountered by scanning 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 a white pixel is encountered for the second time, it is considered to be a white pixel in the data block, such as the last few lines, and 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 of the above-mentioned colored circular two-dimensional code is provided. Referring to Fig. 3, the decoding method can be carried out as follows:

S1: Perform image preprocessing on the color circular 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 in S1 to white; further, after converting to white, the image can be grayscaled, binarized, and Gaussian filtered in sequence; grayscaled And binarization is to facilitate subsequent positioning operations, and Gaussian filtering is to eliminate some image noise;

S3: scan the two-dimensional code picture processed in S2, and find the center of the positioning area;

S4: Taking the center of the positioning area obtained in S3 as the coordinate origin, transforming the original color circular two-dimensional code image into 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 here.

Referring to Fig. 5, it is a schematic diagram of a color circular two-dimensional code in another preferred embodiment of the present invention, including: a black and white positioning area and a colored data area, the positioning area includes a solid circle 1 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 at the third Inside the ring 4 , the third ring 4 is divided into a plurality of data blocks 5 . The difference from that shown in Figure 1 is that the solid circle 1 in the positioning area is white, the first ring 2 is black, and the second ring 3 is white, and the outer side of the solid circle 1 is sequentially connected with a black first ring and a white first ring 2. The second ring 3, that is, the white solid circle 1 is located in the innermost, and then the black first ring 2 is covered outside the white solid circle 1, and the white second ring 3 is covered by the black first ring 2 outside. The third ring 4 is a ring with an angle of 16 equal parts, 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 for data reading, and the other 15 data blocks 5 They are coded in four colors: red, green, blue, and yellow, respectively, coded as 0, 1, 2, and 3, and 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 repeated here.

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

S1: Perform white balance preprocessing on the color circular QR code image, the white balance is to remove the influence of light on the image color;

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

S3: scan the two-dimensional code picture processed in S2, and find the center of the positioning area;

S4: Taking the center of the positioning area obtained in S3 as the coordinate origin, transforming the original color circular two-dimensional code image into 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 that are not described in detail above can be implemented with reference to the technology 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 ring, and the data area is divided by equally dividing the ring to improve the data density. At the same time, the complexity of the decoding algorithm is lower through the transformation of the coordinate system and color coding. The accuracy requirements for the equipment are lower. The two-dimensional code data area of CN103793735A in the background technology requires 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 through the color The operation of turning white or black enables the data area to be reused as a static area during positioning, which functions to separate the pixel interference around the QR code without adding two more rings, which further improves the data density of the QR code. For example, the maximum data volume of the above-mentioned two-dimensional code of the present invention is about 2*10 ⁷ . Under the same conditions, the size of the above-mentioned two-dimensional code of CN103793735A with the same data volume is 19.75 of the two-dimensional code of the present invention. times.

To sum up the above embodiments of the present invention, by adopting 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.

What is disclosed here are only preferred embodiments of the present invention. The purpose of selecting and describing these embodiments in this description is to better explain the principle and practical application of the present invention, not to limit the present invention. Any modifications and changes made by those skilled in the art within the scope of the description shall 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 color 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, and a plurality of data blocks are divided on the third circular ring.

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, a plurality of equal data blocks are formed, one data block is white and serves as a starting point of data reading, the other data blocks are respectively coded by four colors of red, green, blue and yellow, the codes are respectively 0, 1, 2 and 3, and the colors of the adjacent data blocks are different.

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 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.

9. The method for decoding color annular two-dimensional code according to claim 8, wherein: before S1, the method further includes performing white balance processing on the original color annular two-dimensional code picture;

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.