Detect barcodes and QR-codes, and decode their contents.
QR-codes (Quick Response Codes) are popular 2D patterns that contain embedded information, such as a string of text, a URL, etc. They basically work like barcodes, coding information into a high-contrast, geometric pattern that is easier to detect and decode by a machine that more conventional human-written text or drawings.
One can generate QR-codes containing different kinds of information, for example using online QR-code generators, such as http://www.qr-code-generator.com/
JeVois detects and decodes QR-codes and other barcodes. The implementation of the detection and decoding algorithm used in JeVois is from the popular libraru ZBar, found at http://zbar.sourceforge.net/