What is QR code ?


QR Code.
QR Code (Quick Respond Code) is a encrypted form of information that we store in it.It is matrix form of bar code. A QR code uses four standardized encoding modes (numeric, alphanumeric, byte/binary, and kanji) to store data efficiently; extensions may also be used.

A QR code consists of black squares arranged in a square grid on a white background, which can be read by an imaging device such as a camera, and processed using Reed–Solomon error correction until the image can be appropriately interpreted. The required data is then extracted from patterns that are present in both horizontal and vertical components of the image

What is the use of QR Code?

 
Now, First thing come in our mind after knowing what is QR Code, what is the use of QR Code.

QR Code can be use different ways  
1. mobile operating systems
2. URLs
3. Virtual Store
4. QR Code payment
5. Website login
6. WiFi network login
7. Phone no.
8. E-mail address
9. Discount coupons
 and many more.

So in simple terms QR Code is create for different reasons for different uses to make our life easy. 
You can make your own QR Code for your own reasons and accordance of use.

Encoding


The message dataset is placed from right to left in a zigzag pattern, as shown below. In larger symbols, this is complicated by the presence of the alignment patterns and the use of multiple interleaved error-correction blocks.
  • Meaning of format information
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  • Message placement within a QR symbol
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  • Larger symbol illustrating interleaved blocks

Design & Storage


now, how does QR Code design look and, How much space does it have .


Maximum character storage capacity (40-L)
character refers to individual values of the input mode/datatype
Input modeMax. charactersBits/char.Possible characters, default encoding
Numeric only7,0893⅓0, 1, 2, 3, 4, 5, 6, 7, 8, 9
Alphanumeric4,2965½0–9, A–Z (upper-case only), space, $, %, *, +, -, ., /, :
Binary/byte2,9538ISO 8859-1
Kanji/kana1,81713Shift JIS X 0208
Here are some sample QR code symbols:
  • Version 1 (21×21). Content: "Ver1"
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  • Version 2 (25×25). Content: "Version 2"
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  • Version 3 (29×29). Content: "Version 3 QR Code"
  • Version 4 (33×33). Content: "Version 4 QR Code, up to 50 char"
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  • Version 10 (57×57). Content: "VERSION 10 QR CODE, UP TO 174 CHAR AT H LEVEL, WITH 57X57 MODULES AND PLENTY OF ERROR-CORRECTION TO GO AROUND. NOTE THAT THERE ARE ADDITIONAL TRACKING BOXES"
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  • Version 25 (117×117 enlarged to 640x640)
  • Version 40 (177×177). Content: 1,264 characters of ASCII text describing QR codes