QR (quick response) code positioning and recognizing methods

A technology of positioning method and recognition method, which is applied in the field of image recognition, can solve problems such as high restriction recognition efficiency, and achieve the effect of reducing image requirements and accurate geometric distortion correction

Active Publication Date: 2015-07-22
HUAZHONG UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Aiming at the above defects or improvement needs of the prior art, the present invention provides a QR code positioning and recognition method, the purpose of which is to locate and recognize the QR codes that generate geometric distortion through image correction, thus solving the problem of existing QR codes. Scanning recognition requires high technical problems that limit recognition efficiency

Method used

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  • QR (quick response) code positioning and recognizing methods
  • QR (quick response) code positioning and recognizing methods

Examples

Experimental program
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Embodiment 1

[0058] A QR code positioning method, comprising the following steps:

[0059] (1) Image acquisition and preprocessing: acquire the grayscale image of the QR code to be detected, and use the maximum inter-class variance method to perform binarization processing on the collected QR code graphics to obtain the binarized image of the QR code, such as image 3 shown;

[0060] (2) Judgment of positioning graphic coordinates: in the QR code binary image obtained in step (1), according to connected domain extraction, rectangularity analysis and island feature judgment, extract three positioning graphic coordinates of QR code, the specific steps are as follows:

[0061] (2-1) connected domain extraction: the QR code binarization image obtained in step (1), adopts the regional seed growth method to carry out connected domain analysis, and extracts the connected domain of black pixels;

[0062] (2-2) Rectangularity analysis: For each connected domain of black pixels obtained in step (2-...

Embodiment 2

[0067] A method for identifying a QR code, comprising the steps of:

[0068] S1. Perform positioning according to the described QR code positioning method, and obtain a QR code positioning image in the binarized image of the QR code according to the positioning result;

[0069] S2. For the QR code positioning image obtained in step S1, perform multiple erosion and expansion operations on the entire graphic, eliminate the color difference between the black and white modules of the QR code, and finally obtain a unified black area, such as Figure 4 shown. Then use the canny operator to detect the edge, get the QR code edge, the edge of the image is a white point, such as Figure 5 shown.

[0070] S3. For the QR code edge obtained in step S2, obtain the four sides of the QR code through an edge algorithm, and calculate the intersection point of the four sides as a distortion control point; the edge algorithm is an edge tracking algorithm or a point scanning algorithm. The conc...

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Abstract

The invention discloses QR (quick response) code positioning and recognizing methods. The positioning method includes the steps of 1, acquiring an image of a QR code to be detected, and binarizing the image; 2, according to connected area abstraction, rectangularity analysis and island characteristic judging, extracting three positioning image coordinates of the QR code; by means of connected area analysis, extracting connected areas of black pixels; acquiring rectangularities of the connected areas, and reserving the connected area having the rectangularity greater than a screening threshold as a rectangular connected area; reserving the rectangular connected area having black pixel island characteristics as a positioning mark so as to obtain a positioning image. The recognizing method includes the steps of S1, performing positioning according to the positioning method; S2, detecting the edges of the QR code; S3, calculating intersections of four edges as distortion control points; S4, geometrically correcting the image of the QR code by means of a bilinear interpolation algorithm; S5, performing recognizing according to a QR code recognizing algorithm. The QR code positioning and recognizing methods are applicable to positioning and recognizing QR code images having geometric distortion.

Description

technical field [0001] The invention belongs to the field of image recognition, and more specifically relates to a QR code positioning and recognition method. Background technique [0002] QR code is a matrix two-dimensional code symbol. QR code not only has large information capacity, high reliability and low cost, but also can represent various text information such as Chinese characters and images. It has strong security and anti-counterfeiting and is very convenient to use. These characteristics determine that QR two-dimensional codes are suitable for forms, logistics tracking, licenses, inventory and other aspects. [0003] In many application scenarios, the two-dimensional code image acquired by the image acquisition device may have geometric distortion caused by various factors such as shooting angle and image bending. The obtained barcode image is not a standard square, but an arbitrary quadrilateral , due to the existence of this geometric distortion, the tradition...

Claims

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Application Information

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IPC IPC(8): G06K7/10
Inventor 杨华尹周平胡洋
Owner HUAZHONG UNIV OF SCI & TECH
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