2D QR Code Barcode Symbology Overview
What is QR Code & barcode character set, structure, Error Correction Information
What is QR Code
QR Code, stands for Quick Response Code, is a 2D (2-dimensional) matrix symbology which was developed first used for automotive applications by DENSO in 1994. QR Code is with full range of capabilities and maximum data capacity which are encoded in an overall square pattern. Numbers, text, URL, data bytes and images could be encoded by QR Code
. It is an efficient, high density barcode in accordance with ISO/IEC 18004:2006. QR Code is one of the most popular 2D barcode all over the world, which is widely used in many fields, such as smart phones (iPhone, Android, Windows Phone, Blackberry etc.) commercial tracking, entertainment and transport ticketing, product marketing and in-store product labeling.
QR Code Barcode Generator for .NET Applications
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Detailed Information for QR Code Barcode
QR Code Valid Character Set
- Numeric digits from 0 to 9, it could encode up to 2509 numeric digits;
- Alphanumeric digits: upper case letters from A-Z, and special characters like space, $ % * + - . / : ), it could encode up to 1520 alphanumeric characters. In this case, lower case letters will be converted to upper case;
- Byte data in accordance with ISO/IEC 8859-1;
- Kanji characters;
QR Code Structure
QR Code is consisted of encoding region and function patterns, namely finder, separator, timing patterns, and alignment patterns. All four sides of the QR Code are surrounded by the quiet zone border. There are forty sizes of QR Code symbol which ranges from version 1 to Version 40. And the QR Code ranges from 21 X 21 cells to 105 X 105 cells. Each cell encodes one bit and increase by degrees of four cells.
- Quiet Zone
- Finder pattern
- Timing patterns
- Alignment patterns
- Function patterns
- Data and error correction codeword
- Format information
- Version information: QR Code 2005 symbols has version 1 to version 40
- Encoding region
Error correction Level of QR Code
Like Data Matrix ECC 200, QR Code employs the Reed-Solomon error correction algorithm to recover from the damaging part. There are 4 levels error detection levels of QR Code symbology ranges from L, M, Q and H. Storage capacity may relatively reduced when error correction level get higher.
- Level L is able to restore about 7 percentages of codeword.
- Level M is able to restore about 15 percentages of codeword.
- Level Q is able to restore about 25 percentages of codeword.
- Level H is able to restore about 30 percentages of codeword.