Accurate grid sampling method used for recognizing QR code

Abstract

The invention provides an accurate grid sampling method used for recognizing a QR code. According to the method, a pixel value of a coordinate, corresponding to the center position of each depth module in the QR code, in an image, and a large frame of grid sampling is set up by using a central point A of a low right corner point of a top left corner view finding graph, a central point B of a left lower corner point of a top right corner viewing finding graph, a central point C of a top right corner point of a low left corner view finding graph and a central point D of a low right corner correction image; then sampling points of the upper side line and the left side line of a sampling grid can be located accurately and precisely by utilizing the rule that horizontal and perpendicular locating line models alternate in a deep and shallow mode; finally, according to the perspective deformation correction principle, sampling points of the right side line and the lower side line are calculated, so that the sampling grid of the whole graph is obtained. For the QR code with a plurality of correction graphs to be sampled, the method can be adopted for arranging the network in a subsection mode. The method has the advantages of being accurate in location, wide in application, simple in calculation, and completely suitable for an embedded system.

Description

technical field [0001] The invention relates to an accurate grid sampling method for QR code identification. Background technique [0002] Two-dimensional code (two-dimensional barcode) is a black and white pattern distributed in a plane (two-dimensional direction) with a specific geometric figure according to certain rules to record data symbol information. The concept of "0" and "1" bit stream based on the internal logic uses several geometric shapes corresponding to binary to represent text and numerical information, and automatically reads through image input equipment or photoelectric scanning equipment to realize automatic processing of information. [0003] QR code (Quick Response Matrix Code) is a matrix two-dimensional code, which is composed of a square array composed of square modules, and is coded according to the different distributions of deep and shallow modules in the square array. Among them, functional areas (including image finding graphics, separators, p...

AI Technical Summary

Problems solved by technology

[0016] The existing sampling method is to determine the sampling grid by obtaining the horizontal and vertical pitches between the image-finding graphics, between the correction graphics, and between the image-finding graphics and the correction graphics. When the image is geometrically deformed, each module The widths are not equal, resulting in unequal pitches in the corresponding positions of the center positions of each module in the image

When the image is distorted, especially the perspective distortion, and the number of modules is large and the width is nar...

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