2D Barcode
QR Code
Linear Barcode
QR Code
QR Code stands for Quick Response Code. QR Code is a 2D (2-dimensional) matrix symbology which developed first used for automotive applications by DENSO in 1994. QR Code enables customers learn more information about the product or business by scanning the barcode. QR Code could encode numbers, character digits, text, URL, data bytes and images in a relevantly small space. It is widely used in tracking, entertainment and ticketing system at present. Character digits represented in an array of square modules. It is an efficient, high density barcode in accordance with ISO/IEC 18004:2006. Since QR Code scanning is supported by smart phones with proper apps, it gains more popularity.
QR Code Family
There are 4 members in the QR Code family: QR Code Model 1, QR Code Model 2, QR Code 2005 and Micro QR Code.
  • QR Code Model 1 was based on the AIM International Symbology Specification 97-001. QR Code Model 1 was original specification of the QR Code.
  • QR Code Model 2 was based on first edition the ISO/IEC 18004. It is an evolutionary barcode of QR Code with alignment patterns. This additional feature helps navigation in larger symbols. QR Code Model 2 barcode is fully compatible with scanning system of QR Code 2005.
  • QR Code 2005 was based on the second edition of ISO/IEC 18004. QR Code 2005 was enabling with facility to show in a mirror image orientation. It is similar with QR Code Model 2.
  • The Micro QR Code format was based on the International Standard. It is evolutionary version of QR Code 2005 with reduced overhead and data capacity. Size and number encoding in Micro QR Code is relatively small compared with QR Code 2005. Micro QR Code is suitable to use in labels and marking on the component with small space.
Encoding Data of QR Code
The digits are encoded in an overall square pattern. QR Code is with full range of capabilities and maximum data capacity in small space, including:
  • 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;
  • You can also apply ECI - Extended Channel Interpretation, to encode characters apart from the default sets, such as French for QR Code, German, Portuguese, Italian, Spanish, Indonesian and so on.
Structure of QR Code
QR Code is composed of an encoding region and function patterns (encoding no data), namely finder, separator, timing patterns, and alignment patterns. All 4 sides of the QR Code is surrounded by the quiet zone border. Structure of the QR Code including:
  • Quiet Zone
  • Finder pattern
  • Timing patterns
  • Separator
  • 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
There are forty sizes of QR Code 2005 symbol from version 1 to Version 40. 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.
Error Correction of QR Code
Like Data Matrix ECC 200, QR Code also uses the Reed-Solomon error correction algorithm. It helps QR Code to receiver from the damaging part. QR Code symbology offers 4 levels of error detection: L, M, Q and H. Storage will reduce relevantly when level higher. Here are the details of the 4 levels:
  • Level L could restore about 7 percentages of codeword. The length of codeword is 8 bits.
  • Level M could restore about 15 percentages of codeword.
  • Level Q could restore about 25 percentages of codeword.
  • Level H could restore about 30 percentages of codeword.