qr_code v1.0.4 API Reference

QR code generator.

Byte mode character capacities table.

Encoding codewords for Byte mode.

A mask pattern changes which modules are dark and which are light according to a particular rule. The purpose of this step is to modify the QR code to make it as easy for a QR code reader to scan as possible.

Error correction code words and block information.

A QR code uses error correction encoding and mask patterns. The QR code's size is represented by a number, called a version number. To ensure that a QR code scanner accurately decodes what it scans, the QR code specification requires that each code include a format information string, which tells the QR code scanner which error correction level and mask pattern the QR code is using. In addition, for version 7 and larger, the QR code specification requires that each code include a version information string, which tells the QR code scanner which version the code is.

Galios Field GF(256) functions.

Error correction coding uses polynomial long division. To do that, two polynomials are needed. The first polynomial to use is called the message polynomial. The message polynomial uses the data codewords from the data encoding step as its coefficients. For example, if the data codewords, converted to integers, were 25, 218, and 35, the message polynomial would be 25x2 + 218x + 35. In practice, real message polynomials for standard QR codes are much longer, but this is just an example.

A message interleaving module.

A patterns are a non-data element of the QR code that is required by the QR code specification, such as the three finder patterns in the corners of the QR code matrix.

An polynom math library

QR code data structure

SVG structure and helper functions.