A brief introduction to QR codes, and how they work.
Hint: QR codes have “soft spots” down to the left of center, along the very bottom, and along the right edge. Designing or placing logos is possible without blocking the QR code from being read in many cases. –Michael Holtermann
From Wikipedia, the free encyclopedia.
Top image: QR Code for the URL of the English Wikipedia Mobile main page. Note that the white border is part of the encoding.
A QR Code is a matrix barcode (or two-dimensional code), readable by QR scanners, mobile phones with a camera, and smartphones. The code consists of black modules arranged in a square pattern on white background. The information encoded can be text, URL or other data.
Common in Japan, where it was created by Toyota subsidiary Denso-Wave in 1994, the QR code is one of the most popular types of two-dimensional barcodes. QR is the acronym for Quick Response, as the creator intended the code to allow its contents to be decoded at high speed.
Although initially used for tracking parts in vehicle manufacturing, QR Codes are now used in a much broader context, including both commercial tracking applications and convenience-oriented applications aimed at mobile phone users (known as mobile tagging). QR Codes can be used to display text to the user, to add a vcard contact to the users device, to open a URI or to compose a text message or email. Users can also generate and print their own QR Code for others to scan and use by visiting one of several free QR Code generating sites.
QR Codes storing addresses and URLs may appear in magazines, on signs, buses, business cards, or on just about any object about which users might need information. Users with a camera phone equipped with the correct reader application can scan the image of the QR Code to display text, contact information, connect to a wireless network, or open a web page in the phone’s browser. This act of linking from physical world objects is known as a hardlink or physical world hyperlinks.