What Is QR Code?

QR code is a kind of two-dimensional bar code. QR comes from the abbreviation of Quick Response in English, which means fast response. It comes from the inventor's hope that the QR code can make its content be decoded quickly. QR codes can store more information than ordinary barcodes, and there is no need to align the scanner straight when scanning like ordinary barcodes.

QR code

"QR" of QR code is short for Quick Response. This QR code can be read quickly, compared to previous barcodes,

Symbol specifications	21 × 21 module (version 1)-177 × 177 module (version 40)
	(Each specification: add 4 modules on each side)
Data type and capacity	Numeric data: 7,089 characters
	Letter data: 4,296 characters
(Refers to the maximum specification symbol version 40-L)	8-bit byte data: 2,953 characters
	Chinese Kanji and Japanese Kanji data: 1,817 characters
Data representation	Dark modules represent binary "1" and light modules represent binary "0".
Error correction ability	· Level L: about 7% of error-corrected data code words
	· M level: about 15% of data code words
	· Q level: about 25% of data code words that can be corrected
	· H level: about 30% of data code words
Structural link (optional)	A group of information can be represented by 1-16 QR Code code symbols
Mask (inherent)	The ratio of dark to light modules in the symbol can be made close to 1: 1, which minimizes the possibility of decoding difficulties due to the arrangement of adjacent modules.
Extended explanation (optional)	In this way, the symbol can represent data other than the default character set (such as Arabic characters, Guslav characters, Greek letters, etc.), as well as other interpretations (such as data expressed in a certain compression method) or encode the needs of industry characteristics .
Independent positioning function	Have

QR codes were originally designed to make it easier to track parts in car manufacturers. Today, QR codes are widely used in inventory management in various industries. Users can also set

Compared with other two-dimensional codes, QR codes have the advantages of faster reading speed, larger data density, and smaller space. There are three image-finding patterns on the three corners of the QR code. The position, size, and tilt angle of the code are detected using a CCD reading device and decoded to achieve 360-degree high-speed reading.

Using a camera phone with more than 300,000 pixels, and the QR code decoding software in the phone, once the QR code is photographed, the decoding software will automatically interpret this information and display it on the phone screen. There are also cameras that use Webcam to decode, and it is expected that all technology products with lenses will be imported into this QR code mechanism in the future. In addition, QRDOOR and QuickMark provide PC version of QR code decoding software, so that users without camera phones can directly intercept the QR code on the screen through the PC version of QR code decoding software to obtain relevant information, so that general mobile phone and PC users can also Can experience the convenience brought by QR code. ^[1]

The mobile phone navigation technology using QR code and GPS allows users to simplify the process of inputting the target position in the mobile phone. Just by taking a picture of the mobile phone through the QR code, the geographic coordinates can be stored in the mobile phone in time.

To commemorate the 150th anniversary of Hong Kong's stamp issue, Hongkong Post will issue a set of six commemorative stamps and a special stamp sheetlet. This set of stamps also introduces today's popular QR codes. As long as the QR code on the stamps is scanned with a camera phone containing related applications, you can immediately connect to the "150th Anniversary of Hong Kong Stamps Issue" webpage with your mobile phone to view stamp information.

^[2]