toucana Posted April 11 Posted April 11 The omnipresent QR (Quick Response) codes found everywhere these days from restaurant menus, to adverts on bus stops, festival passes, or museum exhibits were first invented back in 1994 at a Japanese company called Denso Wave (デンソーウェーブ), a manufacturer of automobile parts based near Nagoya in Japan. Masahiro Hara, the man who invented QR codes was an engineer at Denso Wave who also happened to be a Go player. One day he was playing a game of Go during his lunchbreak when he stumbled on the idea of using the 19 x 19 matrix of a Go board as a new way of encoding the information of the Kanban (カンバン ) system for tracking components and spare parts which is extensively used in the Japanese car industry. It occured to him that a 2-dimensional matrix system of encoding with inbuilt error correction could store and process information far more efficiently than the linear bar code systems currently in use. A new YT video gives a concise explanation of quite how all those hieroglyphic symbols in a QR coding system work: https://www.youtube.com/watch?v=Qb4wq2auXXk It’s basically a formatted bit-stream of text. Version 1 is a 21 x 21 matrix that can store up to 17 UTF-8 characters when using low error correction. Version 40 is a 177 x 177 matrix that can store almost 3K of text. The error correction system is based on Reed-Solomon Codes which is a method widely used in CD, DVD and Blu-ray disks - it also allows you to place a trademark logo or image in the middle of a QR glyph without compromising the readability of the information. The coloured image below gives a handy guide to what the different bits of of a QR code do - The mauve #6 area is where the data is actually written. and the yellow #7 area is the Error Correction data.
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