QR code : Java Glossary


QR code

QR (Quick Response) code. 2-dimensional bar codes designed two be read by cellphone cameras, sometimes without even clicking the shutter. A QR code might contain a URL (Uniform Resource Locator), a latitude/longitude or a text message. They are most popular in Japan. You need an app such as Android bar code scanner, Microsoft Tag or MIO (Masivo Integrado de Occidente) Reader.

Here is the QR code for the URL http://mindprod.com

mindprod.com URL QR bar code

This QR code gives the date start and start and end times of Earth Hour in 2011.

2011 Earth Hour Details as a QR bar code

Denso Wave, a Japanese corporation hold the patent on them, but allows people to use them freely with out royalty.

You can specify how much Reed-Solomon redundancy you want to allow images to be read even when images are degraded. A single image can hold up to 2,953 bytes. These are similar to the codes used in print-it-yourself postage, but without the digital signing.

I have not yet found an app that will let you decode QR codes on a desktop computer. If you find one, please let me know.

You can use part of the QR code real estate for decorative art work and the code will still work.

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