CN111199163A - Edge detection and positioning identification method of annular code - Google Patents

Edge detection and positioning identification method of annular code Download PDF

Info

Publication number
CN111199163A
CN111199163A CN201911420872.2A CN201911420872A CN111199163A CN 111199163 A CN111199163 A CN 111199163A CN 201911420872 A CN201911420872 A CN 201911420872A CN 111199163 A CN111199163 A CN 111199163A
Authority
CN
China
Prior art keywords
image
code
annular
annular code
algorithm
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
CN201911420872.2A
Other languages
Chinese (zh)
Inventor
徐波
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to CN201911420872.2A priority Critical patent/CN111199163A/en
Publication of CN111199163A publication Critical patent/CN111199163A/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/14—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation using light without selection of wavelength, e.g. sensing reflected white light
    • G06K7/1404—Methods for optical code recognition
    • G06K7/1439—Methods for optical code recognition including a method step for retrieval of the optical code
    • G06K7/1452—Methods for optical code recognition including a method step for retrieval of the optical code detecting bar code edges
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/14—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation using light without selection of wavelength, e.g. sensing reflected white light
    • G06K7/1404—Methods for optical code recognition
    • G06K7/1408—Methods for optical code recognition the method being specifically adapted for the type of code
    • G06K7/1417—2D bar codes
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
    • G06K7/00—Methods or arrangements for sensing record carriers, e.g. for reading patterns
    • G06K7/10—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation
    • G06K7/14—Methods or arrangements for sensing record carriers, e.g. for reading patterns by electromagnetic radiation, e.g. optical sensing; by corpuscular radiation using light without selection of wavelength, e.g. sensing reflected white light
    • G06K7/1404—Methods for optical code recognition
    • G06K7/1439—Methods for optical code recognition including a method step for retrieval of the optical code
    • G06K7/1443—Methods for optical code recognition including a method step for retrieval of the optical code locating of the code in an image

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Electromagnetism (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Artificial Intelligence (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Image Analysis (AREA)

Abstract

The invention discloses an edge detection and positioning identification method of an annular code, which belongs to the field of two-dimensional codes and specifically comprises the following steps: acquiring an image to be detected; preprocessing an image to be detected, determining the center coordinate and the radius of the annular code through a quadrant iteration center algorithm, framing a maximum circumscribed circle of the annular code and a circumscribed rectangle of the annular code, and intercepting the annular code image from the image to be detected according to the circumscribed rectangle; and preprocessing the annular code image, screening and identifying the locator through a preferred algorithm and correcting the locator through a perspective transformation algorithm. The invention sets the shape for the ring code, abandons the shape with the ratio of black and white as the locator, has stronger anti-interference and deformability, and enhances the positioning accuracy of the ring code.

Description

Edge detection and positioning identification method of annular code
Technical Field
The invention relates to the technical field of two-dimensional codes, in particular to an edge detection and positioning identification method for an annular code.
Background
The traditional square two-dimensional code usually embeds double-layer squares as positioning areas at three corners, the black-white ratio of the double-layer squares is 1:1:3:1:1, the position of the two-dimensional code is easy to position in a real scene by utilizing the isotropy of the rectangle, meanwhile, the coding area of the data code can be framed according to the square edges, and then black and white blocks of the data area are extracted according to specific positions and sequences, so that the decoding purpose is achieved. By utilizing the anisotropy, the interference of rotation, scaling and the like of a scene during shooting on two-dimensional code identification can be resisted, but once a positioning area is polluted, such as an outer rectangular frame is thickened, pixels are lost and the like, an error data area is easily obtained, and decoding failure is caused.
Novel two-dimensional codes, such as the radio-type "daisy code" used in WeChat applets, utilize a double-layered ring as a locator. In practical use, the locator is still found according to a certain proportion, the area where the two-dimensional code is located is determined, and then binary information is obtained according to the black and white blocks on each ray, although the coding area is not divided by the locating area, the locating accuracy is improved compared with the traditional two-dimensional code, but the mode of finding the locator according to the proportion usually has a disadvantage: the black-white ratio of the locator is slightly affected by the interference of illumination, dirt and the like in a general real scene, and the decoding failure can be caused.
Disclosure of Invention
The invention provides an edge detection and positioning identification method of an annular code, which solves the problem that in the prior art, if a two-dimensional code is polluted, a locator is searched based on proportion, an error data area is easily obtained, and decoding fails.
The technical scheme of the invention is realized as follows:
an edge detection and positioning identification method of annular codes specifically comprises the following steps:
s1, acquiring an image to be detected;
s2, preprocessing the image to be detected, determining the center coordinate and radius of the annular code through a quadrant iteration center algorithm, selecting the maximum circumscribed circle of the annular code and the circumscribed rectangle of the annular code, and intercepting the annular code image from the image to be detected according to the circumscribed rectangle;
and S3, preprocessing the annular code image, screening and identifying the locator through a preferred algorithm and correcting the locator through a perspective transformation algorithm.
As a preferred embodiment of the present invention, the step S2 is to pre-process the image to be detected, and specifically includes the following steps:
carrying out filtering binarization processing on an image to be detected;
extracting a connected region in the binary image, and filtering the connected region with the area smaller than a threshold value;
and storing the central points of the remaining connected regions into a list.
As a preferred embodiment of the present invention, the filtering binarization processing on the image to be detected specifically comprises
Eliminating partial noise of the image to be detected by a median filtering method, carrying out image binarization processing by an Otsu algorithm, and filtering small noise and repairing the contour by open operation.
As a preferred embodiment of the present invention, in step S2, the central coordinates and the radius of the ring code are determined by a quadrant iteration center algorithm, and the maximum circumscribed circle of the ring code and the circumscribed rectangle of the ring code are framed, which specifically includes the following steps:
calculating an average point of the central point, taking the average point as a coordinate origin, and dividing into four quadrants; calculating the circle center coordinates of the three point coordinates from the point coordinates closest to the average point in the three quadrants, dividing the circle center coordinates into four quadrants as a new coordinate origin for iterative operation, and determining the coordinates as the coordinates of the central position of the ring code, wherein the coordinates fluctuate within a small range from iteration to the central position;
fitting a circle or an ellipse according to the nearest point coordinate to obtain a circumscribed rectangle, and obtaining the inner ring radius of the annular code according to the circumscribed rectangle;
and obtaining the maximum radius of the annular code according to the central position coordinate of the annular code, the radius of the inner ring, the radius increment and the radius increment number, and solving the circumscribed rectangle of the annular code.
As a preferred embodiment of the present invention, the preprocessing of the ring code image in step S3 specifically refers to
Carrying out filtering binarization processing on the annular code image;
and extracting a connected region in the binary image, and filtering the connected region with the area larger than or smaller than a threshold value.
As a preferred embodiment of the invention, the filtering and binarization processing of the annular code image specifically comprises
Eliminating partial noise of the image to be detected by a median filtering method, carrying out image binarization processing by an Otsu algorithm, and disconnecting the narrow connection of the material edge in the binarized image by open operation.
In a preferred embodiment of the present invention, in step S3, a set of candidate locators is obtained according to the set shape of the locators, and the identified locators are screened by a preferential algorithm
Setting all positioning point sets as C, selecting three points from the positioning point sets as a group to obtain circle centers, comparing the circle centers with the center coordinates of the annular codes, and taking the three points corresponding to the circle center closest to the circle centers as positioning symbols;
determining the ordering of the three locators by a dot product algorithm;
and determining the correctors according to the three locators through an arithmetic mean algorithm.
As a preferred embodiment of the invention, perspective transformation correction is carried out by the coordinates of the three locators and the correctors corresponding to the coordinates of the annular code image.
The invention has the beneficial effects that: the shape of the ring code is set, the shape with a black-white ratio is abandoned as a locator, the anti-interference and deformation capabilities are strong, and the positioning accuracy of the ring code is enhanced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic diagram of an embodiment of a ring code;
FIG. 2 is a flowchart of an edge detection and location identification method of a ring code according to the present invention;
fig. 3 is a flowchart of step S2;
fig. 4 is a flowchart of step S3;
FIG. 5 is a flowchart of decoding a ring code;
FIG. 6 is a diagram illustrating an example of ring code positioning amplification and distortion correction.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 shows a structure diagram of each region of the ring code, wherein each ring black dot represents a code of 1, a white region represents a code of 0, and the functions of the rest modules are as follows: the decoration area is only used for decoration of the annular code and can be used for transmitting product information; the positioning area is used for determining the position of the annular code, the initial coding position and the coding direction; the correction area can form parameter variables required by image distortion correction by matching with the positioning area, the auxiliary information area stores information such as transmission content type, total data length, error correction parameters and the like, and the correctness of transmission information can be ensured according to the auxiliary information area in the decoding process; the data coding area is a second inner ring area to an outermost ring area and comprises binary codes of transmission information and error correction words.
As shown in fig. 2, the present invention provides an edge detection and location identification method for a ring code, where the ring code is the above ring code, and the method specifically includes the following steps:
s1, acquiring an image to be detected;
s2, preprocessing the image to be detected, determining the center coordinate and radius of the annular code through a quadrant iteration center algorithm, selecting the maximum circumscribed circle of the annular code and the circumscribed rectangle of the annular code, and intercepting the annular code image from the image to be detected according to the circumscribed rectangle;
(1) because the camera is easily influenced by environmental noise when shooting the two-dimensional code, part of noise points can be eliminated by using median filtering, then image binarization is carried out by using an Otsu algorithm, and small noise points and contour restoration are filtered by using open operation.
(2) And extracting the connected regions in the processed binary image, calculating the area of each connected region, and filtering the contour with an excessively small area. Because the coding points are all formed by solid black circles, the height of the minimum rectangle outside the coding points is set as l, the width is set as w, and the area with the width-height ratio not meeting 0.6 & lt w/l & lt 1.8 is primarily filtered. Meanwhile, a noise point area can be further screened out by utilizing the proportion between the minimum circumscribed rectangle and the outline area, wherein cnt _ area is set as the outline area, ret _ area is set as the small circumscribed rectangle area, points which do not meet abs ((cnt _ area/rct _ area) -1) <0.2 condition are filtered out, and the remaining outline center points are collected and stored in a list.
(3) In order to estimate the center point of the annular code, an algorithm for calculating the outer circle contour by using arithmetic mean points is designed from the shape and the code distribution of the annular code. Through experiments, the arithmetic coordinate average of all the point positions in the point set list obtained by screening in the step (2) in various backgrounds basically falls within the inner ring of the ring code, the point set is P ═ P1, P2, … Pn }, and the arithmetic mean point calculation formula is as follows:
Figure BDA0002352350040000051
dividing the point set into four quadrants by taking the arithmetic mean point as a coordinate origin, respectively selecting three quadrants and taking the point coordinate closest to the arithmetic mean point, wherein the formula is as follows:
Figure BDA0002352350040000052
the equation of a circle can be determined according to three points, and the equation of the circle is solved by the three points, namely, the circle center is set as Pmin _1 (x1, y1), Pmin _2 (x2, y2), and Pmin _3 (x3, y3), the solution formula is derived:
Figure BDA0002352350040000053
solving the above-mentioned ternary quadratic equation
a＝2*(x2-x1)，b＝2*(y2-y1)，c＝x2*x2+y2*y2-x1*x1-y1*y1，d＝2*(x3-x2)，
e＝2*(y3-y2)，f＝x3*x3+y3*y3-x2*x2-y2*y2.
The circle center coordinates can be expressed as:
X＝(b*f-e*c)/(b*d-e*a)，Y＝(d*c-a*f)/(b*d-e*a)
and then dividing quadrants by the center (X, Y) to obtain the nearest point equation to obtain the center according to the method, iterating until the center position fluctuates in a small range, and determining the center position coordinate of the annular code. (if the noise of the center icon is less, the center is close to the center of the inner ring, and if the noise is more, the detection outer frame at the back is not influenced).
(4) And (4) detecting the radius increment by taking the center of the stopped iteration in the step (3) as a circle center. According to the structure of the annular code, the number of the point sets contained in the circle is increased as the radius is increased, the radius increment is determined by the closest point calculated in the step (3), the closest point is fitted to the circle or the ellipse to obtain an circumscribed rectangle, the length and the width of the circumscribed rectangle are added and divided by 4 to be approximated as the radius of the inner ring, and the radius increment is one sixth of the radius of the inner ring. As the radius increment is enlarged, the point set is increased by no more than 5, and amplification is stopped. At this time, the point set within the maximum radius is used as the whole annular code data area, namely the circumscribed rectangle of the outermost layer coding ring of the annular code.
(5) And returning the circumscribed rectangle as the corresponding coordinate of the interesting area to the original image according to the initial scaling, intercepting the annular code, amplifying the original image, and uniformly scaling the image with the size of 800 x 800.
Thus, the steps of positioning the two-dimensional code in the image to be detected and selecting and amplifying the outer circle are completed, the background can be removed, and the detection of subsequent positioning points and correction symbols is facilitated.
And S3, preprocessing the annular code image, screening and identifying the locator through a preferred algorithm and correcting the locator through a perspective transformation algorithm.
① since the ring code is easy to be affected by the environment noise when it is shot by the camera, the median filter can be used to eliminate part of the noise, then the image binarization is performed by the Otsu algorithm.
② connected regions in the processed binary image are extracted to calculate the area of each connected region, and the area is usually calculatedThe areas are normally distributed under the condition, most areas are the areas of the external rectangles for filling the materials, and the rest areas which are larger or smaller appear in the interruption areas caused by the non-standard binaryzation, so that all the outline areas are sorted, the areas which are too large or too small are filtered, the length-width ratio of the external rectangles is calculated, and the length-width ratio of the key point icons is close to 1: and 1, filtering out the outline with abnormal aspect ratio. The positioning points are composed of three triangles, and the detection of the triangles is carried out by using the proportion between the polygon approximation algorithm of OpenCV and the minimum circumscribed rectangle and the outline area. In order to improve the detection rate, the detection threshold value is widened as much as possible, false detection can be caused as a result, a preferred algorithm of the triangular positioning points is designed for eliminating the positioning points of the false detection, the algorithm is based on the fact that the three triangular positioning points are all positioned on the inner ring, the connecting lines of the three positioning points and the circle center are mutually in a right angle, and even if an image is deformed, the circle center of a circular equation obtained by the three positioning points is also close to the center of the inner ring. Fitting the point set in the annular code region to an ellipse E by using a fitEllipse function of opencv to obtain a central point Ecenter. If the triangular positioning point detection exceeds three points, combining the triangular positioning point detection, and setting the candidate point set as C as { a ═ a1，a2，…anIn all, there are
Figure BDA0002352350040000061
Combining, solving a circle equation by taking every three points as a group, and solving a circle center set Pc ═ Pc1，Pc2…PcKCentral point E fitted with ellipse EcenterComparing the distances, wherein one group of the closest distances is a real positioning point Ctruth：
Ctruth＝min_distance{Ecenterto Pc}
After the three positioning points are obtained, the three positioning points need to be sequenced to determine a starting point, wherein the end position of the long arc in the counterclockwise direction is the starting point of information coding, namely the lowest triangular locator in fig. 1, and the sequencing of the three positioning points is determined by a point multiplication algorithm.
Similarly, if a plurality of correction points are detected, the selection is usedAnd (3) optimal algorithm screening, wherein a square is formed by the correction point and the three positioning points, the intersection point of the diagonals is the midpoint of each end point, and the specific process comprises the following steps: if more than one correction point is detected, the candidate point set is set as Pcorrect＝{b1，b2…bnFifthly, each correction point is compared with the second ordered positioning point Ctruth_2Performing arithmetic mean D ═ D1，d2…dnC, to follow the first and third positioning points Ctruth_1，Ctruth_3Result of arithmetic mean C13Comparing, the nearest is the correction point Pcorrect_truth：
Pcorrect_truth＝min_distance{C13to D}
③ FIG. 6(c) shows the result of performing perspective transformation correction on the original image 6(b) using the four coordinates of the locator and the corrector corresponding to the four coordinates of the locating point.
The difference from other two-dimensional codes is that the coordinates of the positioning point and the correctors of the annular code are changed along with the change of the number of codes, and the larger the number of codes is, the smaller the radius of the inner ring where the positioning point and the correctors are located is. So that the coordinates of the fixed positioning point are different from those of other two-dimensional codes. The invention uses relative coordinate formula to determine the coding point after perspective transformation.
As shown in the flowchart of decoding the ring code in fig. 5, after determining three position areas of the locator, the counterclockwise end of the long arc is used as the initial coding position, the image block data is read along the circumferential interval with the radius r, one forty-th of the circumferential length is used as the step size of the reading interval and the width and height of the image block, if the gray scale coverage area in the image block is greater than one half of the block area, the stored coding byte is 1, otherwise, the coding byte is 0. Thus, inner loop coded data can be obtained, and the auxiliary indication information can be obtained after decoding according to the table 1. After the encoded information of the auxiliary information area is acquired through RS error correction, in order to check the accuracy of the information and the number of rings, the mode indicator obtained by inner ring decoding is set to be m, the length of the transmission character is p, the number q of encoded bytes can be calculated through the first step, if q is equal to k, the inner ring decoded data is correct, and otherwise, the decoding fails.
Table 1 auxiliary indication code (digit)
Encoding mode indicator Transmitting character length Total length of code Number of data blocks Auxiliary indicator code error correction code
2 6 8 8 16
After the inner ring data is decoded without errors, the total length n of the coded data is recorded in bits 9-16, and the number of the ring code rings and the data length of the transmitted coded information can be calculated according to the initial storage capacity of the inner rings and the fixed storage increment of each ring. Showing each ring information coding block obtained according to the ring number, the radius increment and the storage increment, obtaining coded data according to the gray scale area ratio, reading the coding blocks from the second ring inside in sequence, enabling the initial coding position and the circle center of each ring to be on the same straight line, carrying out RS (n, k) coding error correction on the finally obtained code, carrying out XOR operation with a mask, and taking the first 8n coding bits to be the binary code of the transmitted information. And finally, grouping and decoding the binary data according to the information coding bit number specified by the coding mode. In the decoding process for different coding modes, the implemented grouping criteria are specifically shown in the following table:
Figure BDA0002352350040000081
the invention has the beneficial effects that: the shape of the ring code is set, the shape with a black-white ratio is abandoned as a locator, the anti-interference and deformation capabilities are strong, and the positioning accuracy of the ring code is enhanced.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims (8)

1. An edge detection and positioning identification method of a ring code is characterized by comprising the following steps:
s1, acquiring an image to be detected;
s2, preprocessing the image to be detected, determining the center coordinate and radius of the annular code through a quadrant iteration center algorithm, selecting the maximum circumscribed circle of the annular code and the circumscribed rectangle of the annular code, and intercepting the annular code image from the image to be detected according to the circumscribed rectangle;
s3, preprocessing the annular code image, obtaining a candidate locator set according to the set shape of the locator, screening and identifying the locator through a preferred algorithm and correcting through a perspective transformation algorithm.
2. The method for detecting, locating and identifying the edge of the annular code according to claim 1, wherein the step S2 is to pre-process the image to be detected, and specifically comprises the following steps:
carrying out filtering binarization processing on an image to be detected;
extracting a connected region in the binary image, and filtering the connected region with the area smaller than a threshold value;
and storing the central points of the remaining connected regions into a list.
3. The method for detecting, locating and identifying the edge of the annular code according to claim 2, wherein the filtering binarization processing of the image to be detected specifically comprises
Eliminating partial noise of the image to be detected by a median filtering method, carrying out image binarization processing by an Otsu algorithm, and filtering small noise and repairing the contour by open operation.
4. The method for detecting, locating and identifying the edge of the ring code according to claim 2, wherein in step S2, the center coordinates and the radius of the ring code are determined by a quadrant iteration center algorithm, and the maximum circumscribed circle of the ring code and the circumscribed rectangle of the ring code are selected, specifically comprising the following steps:
calculating an average point of the central point, taking the average point as a coordinate origin, and dividing into four quadrants; calculating the circle center coordinates of the three point coordinates from the point coordinates closest to the average point in the three quadrants, dividing the circle center coordinates into four quadrants as a new coordinate origin for iterative operation, and determining the coordinates as the coordinates of the central position of the ring code, wherein the coordinates fluctuate within a small range from iteration to the central position;
fitting a circle or an ellipse according to the nearest point coordinate to obtain a circumscribed rectangle, and obtaining the inner ring radius of the annular code according to the circumscribed rectangle;
and obtaining the maximum radius of the annular code according to the central position coordinate of the annular code, the radius of the inner ring, the radius increment and the radius increment number, and solving the circumscribed rectangle of the annular code.
5. The method for detecting, locating and identifying the edge of the annular code as claimed in claim 1, wherein the preprocessing of the annular code image in step S3 specifically means
Carrying out filtering binarization processing on the annular code image;
and extracting a connected region in the binary image, and filtering the connected region with the area larger than or smaller than a threshold value.
6. The method for detecting, locating and identifying the edge of the annular code according to claim 5, wherein the filtering and binarization processing of the annular code image specifically comprises
Eliminating partial noise of the image to be detected by a median filtering method, carrying out image binarization processing by an Otsu algorithm, and disconnecting the narrow connection of the material edge in the binarized image by open operation.
7. The method as claimed in claim 1, wherein the step S3 is performed by obtaining a set of candidate locators according to the set shape of the locators, and filtering the identified locators by a preference algorithm
Setting all positioning point sets as C, selecting three points from the positioning point sets as a group to obtain circle centers, comparing the circle centers with the center coordinates of the annular codes, and taking the three points corresponding to the circle center closest to the circle centers as positioning symbols;
determining the ordering of the three locators by a dot product algorithm;
and determining the correctors according to the three locators through an arithmetic mean algorithm.
8. The method for detecting and identifying the edge of the annular code as claimed in claim 7, wherein the perspective transformation correction is performed by the coordinates of the three locators and the correctors corresponding to the coordinates of the annular code image.
CN201911420872.2A 2019-12-31 2019-12-31 Edge detection and positioning identification method of annular code Withdrawn CN111199163A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201911420872.2A CN111199163A (en) 2019-12-31 2019-12-31 Edge detection and positioning identification method of annular code

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201911420872.2A CN111199163A (en) 2019-12-31 2019-12-31 Edge detection and positioning identification method of annular code

Publications (1)

Publication Number Publication Date
CN111199163A true CN111199163A (en) 2020-05-26

Family

ID=70746206

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201911420872.2A Withdrawn CN111199163A (en) 2019-12-31 2019-12-31 Edge detection and positioning identification method of annular code

Country Status (1)

Country Link
CN (1) CN111199163A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112686070A (en) * 2020-11-27 2021-04-20 浙江工业大学 AGV positioning and navigation method based on improved two-dimensional code
CN112949625A (en) * 2021-01-29 2021-06-11 西安电子科技大学 Target identification method and system based on centroid contour distance

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112686070A (en) * 2020-11-27 2021-04-20 浙江工业大学 AGV positioning and navigation method based on improved two-dimensional code
CN112949625A (en) * 2021-01-29 2021-06-11 西安电子科技大学 Target identification method and system based on centroid contour distance

Similar Documents

Publication Publication Date Title
CN106485183B (en) A kind of Quick Response Code localization method and system
CN107633192B (en) Bar code segmentation and reading method based on machine vision under complex background
CN106960208B (en) Method and system for automatically segmenting and identifying instrument liquid crystal number
JP5003225B2 (en) Code processing device
CN109190742B (en) Decoding method of coding feature points based on gray feature
CN110363202B (en) Pointer instrument value reading method and computer terminal
JP2007317184A (en) Two-dimensional bar code, and encoding and decoding method thereof
CN108573511B (en) Point-distributed cooperative coding mark and identification and positioning method thereof
CN109215016B (en) Identification and positioning method for coding mark
CN109948393B (en) Method and device for positioning one-dimensional bar code
CN111241860A (en) Positioning and decoding method for arbitrary material annular code
CN111199163A (en) Edge detection and positioning identification method of annular code
CN104866859A (en) High-robustness visual graphical sign and identification method thereof
CN106407973B (en) It is marked on the Robust identifying method of the AR code on cylinder
CA3045391C (en) Method for detection and recognition of long-range high-density visual markers
CN112001383A (en) Water meter code intelligent identification method based on convolutional neural network technology
CN114792104A (en) Method for identifying and decoding ring-shaped coding points
CN111222507A (en) Automatic identification method of digital meter reading and computer readable storage medium
CN110458843A (en) The dividing method and system of mask images
CN114612490B (en) Scenedesmus cell statistical method based on microscope image
CN113076768B (en) Distortion correction method for fuzzy recognizable two-dimensional code
CN113129397B (en) Decoding method of parallelogram coding mark based on graphic geometric relation
CN112102316B (en) Method and device for acquiring distribution of product defect positions
JPS62267889A (en) Character reading system
CN115880683A (en) Urban waterlogging ponding intelligent water level detection method based on deep learning

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
WW01 Invention patent application withdrawn after publication

Application publication date: 20200526

WW01 Invention patent application withdrawn after publication