Two-dimension code reader and reading method, portable terminal and digital camera

Abstract

When a two-dimensional code having data cells (referred to as DC) comprising two-dimensional data, positioning finder patterns (referred to as FP) and an alignment pattern (referred to as AP) is input, the positions of FP are detected by evaluating the proximity from patterns in three horizontal, vertical and inclined directions. The position of AP is detected by conducting the template matching after the rotation correction of part of the input image. The version of the code is determined by calculation of the number of cells from the widths and positions of FP. Coordinate conversion expressions for converting the positions of DC into their coordinate positions based upon the positions of FP and AP and the version are determined and DC are cut out. The array of the cut out DC is decoded for reading the two-dimensional code.

Description

technical field [0001] The present invention relates to a 2D code reading device, a 2D code reading method, a 2D code reading program, a recording medium for the program, a portable terminal, and a digital camera. A 2D code reading device for reading a 2D code, a 2D code reading method, a 2D code reading program, and a recording medium for the program. Background technique [0002] In recent years, mobile phones with built-in cameras have become widespread. In the above-mentioned mobile phone with a camera, etc., when using the camera to take pictures of the two-dimensional code and read the information recorded in the two-dimensional code, in the general mobile phone with low processing capacity, etc., from the aspect of processing capacity It is considered that it is necessary to make it possible to read a two-dimensional code by a method with a small amount of processing. [0003] As an example of a two-dimensional code, there is a QR code (Quick Response Code) which is...

AI Technical Summary

Problems solved by technology

[0020] In the detection of the ranking pattern P, the expected coordinates of the expected existence of the ranking pattern P are calculated based on the coordinates of the positioning pattern F, and its surroundings are precisely searched to perform detection. In the case where the coordinates of the ranking graph P are greatly deviated, there is a problem that it takes a long time to perform a precise search to detect the correct position of the actual ranking graph P.

[0021] In addition, although the binary image that has been subjected to binary processing is subjected to a precise search for the ranking pattern P of the 2D code (QR code), due to errors in the binary processing, white pixels may be broken and Fragmentation of black pixels, the problem of false detection of the ranking pattern P due to the above-mentioned fragmentation and the impact of fragmentation

[0022] When the number of pixels constituting a two-dimensional code (QR code) is as high as a certain level, even if a plurality of ranking patterns P are arranged, the photographed image will be distorted to some extent. If any one of the ranking patterns P can be detected, the The 2-dimensional code is constructed according to the principle that the data pixels of 2-dimensional data can be stably cut out (that is, the data value of each data pixel is determined), but in this case, it is necessary to span multiple positions of the ranking pattern P For detection, there is a problem of increased processing time

[0023] When determining the data value of a data pixel (that is, cutting out a data pixel), the data image is determined by investigating the number of black pixels and white pixels within a specific range based on the size of the pixel, that is, the pixel size. Therefore, it not only increases the processing time before the decision, but also easily causes errors in the data value of the data pixel due to the error in the binary processing, accompanied by the occurrence of white pixel fragmentation and black pixel fragmentation. is also a problem

[0024] In addition, when calculating the number of pixels according to the distance between the positioning patterns F, and determining the version of the 2D code (QR code), there is an error due to the distortion of the input image, and the correct version cannot be determined, resulting in a 2D code (QR code) version. Code reading failure problem

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