Go QRCode Two-dimensional code introduction and common control recommendations

What is a QR code?

QR code is a matrix two-dimensional code symbol developed by Nippon Denso Company in September 1994, which has the advantages of large information capacity, high reliability, multi-text information of Chinese characters and images, strong security and so on, with one-dimensional barcode and other two-dimensional barcode.

Basic features of QR code symbols

Symbol specifications	21X21 Module (version 1) -177x177 module (version 40)
	(Each specification: Add 4 modules per side)
Data type and capacity	· Numeric data: 7,089 character (s)
	· Letter data: 4,296 character (s)
(refers to the maximum size symbol version 40-L level)	· 8-bit byte data: 2,953 character (s)
	· Chinese kanji, kanji data: 1,817 character (s)
Data representation method	The Dark module represents the binary "1" and the light module represents the binary "0".
Error correction capability	· L-level: about 7% of the data code Word can be corrected
	· M-class: approx. 15% Data code Word Error
	· Q-level: About 25% of the data code Word can be corrected
	· H-Class: About 30% of the data code Word can be corrected
Structure Link (optional)	Use 1-16 QR code symbols to represent a set of information
Mask (intrinsic)	The ratio of dark to light modules in the symbol is close to 1:1, which minimizes the possibility of decoding difficulties due to the arrangement of adjacent modules.
Extended Interpretation (optional)	This way the symbol can represent data other than the default character set (such as Arabic characters, Cyrillic characters, Greek letters, etc.), as well as other interpretations (such as data expressed in a compressed manner) or coding the needs of the industry.
Independent positioning function	Yes

QRCode Two-dimensional code version display

There are 40 types of QR code symbols, version 1, version 2 "" Version 40 respectively. Version 1 specifications for the 21 Module x21 module, version 2 for the 25 module X25 module, and so on, each version of the symbol is more than the previous version of 4 modules per side, until version 40, the specification is 177 module x177 module. The highest version of the 40 can accommodate up to 1850 uppercase letters or 2,710 digits or 1108 bytes, or more than 500 Chinese characters, which is about dozens of times times higher than the normal barcode information capacity. Because of its high-density coding, the information capacity is large, so it is widely adopted.

1 for version 2 (a total of 25 module X25 modules):

Figure 1

If you use the smartphone QR code Pat, is a URL link "http://www.lgms.net". Access it, you can go directly to a website.

What role does this play? A bridge between the physical world and the virtual world. So, some people liken it to "the sensor of the Internet of Things". This is not our focus, we will not repeat it. Let's talk about the structure of the QR code.

First Look at 2:

Figure 2

Figure 3 Structure of QRCode versions 1 and 2

Figure 4 The color version of Figure 1

Figure 5

Common QRCode Two-dimensional code control recommendations

Currently used for program development of barcode products are mainly divided into barcode font and barcode Control two categories, barcode font can be very convenient as a special font in the application or office output, and barcode control is mainly used to embed in the software, client browsing does not require font support.

Here we recommend 2 powerful QR code controls. They are the leadtools 2D Barcode SDK Module and the complete Barcode package barcode control, respectively.

The LeadTools 2D Barcode SDK module is the most comprehensive barcode toolkit on the market and supports reading and writing of more than 100 barcodes, including all major 1D and 2D barcodes. And it contains a number of active-code demonstration projects that contain versions of C, Visual C + + (MFC), vb.net, and C #.

Dautomation QR Code Barcode font and encoder is a collection of components that can be used to generate Qr-code barcode symbols using fonts and graphics. Qr-code is a two-dimensional (2D) matrix-type barcode symbol set, similar to Data matrix and Aztec, with the ability to encode large amounts of data.

Go QRCode Two-dimensional code introduction and common control recommendations