What are QR codes?
In case you haven't had the opportunity to encounter a QR code in person, they’re similar to the familiar barcode that has been in use for years to track and price products. The key difference between the two dimensional QR code and the single dimensional barcode is the amount of data they contain. Quick Response codes are also known as hardlinks or physical world hyperlinks. QR Codes store up to 4,296 alphanumeric characters of arbitrary text. This text can be anything, for example, a URL, contact information, a telephone number, even a blog post! QR codes can be read by an optical device with the appropriate software. Such devices range from dedicated QR code readers to mobile phones.
By scanning a QR code with your iPhone or other camera enabled smart device, you activate any number of phone functions, including linking your phones web browser to a web page destination. In this blog post, I will demonstrate how to use the Google Chart API to generate a QR code that references a destination on the web. This can be especially useful for linking to smart device specific down-loadable content. For example: if your website has a corresponding iPhone app, you could provide a QR code in lieu of an iTunes destination URL. Another good example would be using QR code images on a web page, that point to podcasts or videos that are hosted on iTunes.
There are a number of websites that can generate a QR code image. These sites provide a Form to enter a URL or a message, then generate the QR code image for you to download and later place on your web page. While this is a convenient method, I wanted a means to generate a QR code image on demand. Authoring this type of application would be no simple matter. Fortunately, Google has done all of the work for me! Google Charts provides a simple means to generate a QR Code image as a service.
Here is an example of generating a QR code image for the My developerWorks iphone app on iTunes:
<img src="https://chart.googleapis.com/chart?chs=250x250&cht=qr&chl=http://itunes.apple.com/us/app/developerworks/id391162970?mt=8&choe=UTF-8" alt="Download developerWorks app" />
QR codes have a different set of required parameters from any other chart:
The usage of QR codes is growing rapidly since they are tailor made for quickly and easily linking content to smart phones. From basic magazine pages, business cards, or advertisements, digital linkages can be established to websites or any other destination URL. With our growing reliance on mobile phones... QR codes removes the barrier of typing out long URL strings on tiny keyboards. By supplementing a destination URL with a users physical location (via a geolocation service), QR code images can provide even greater value. As smart device applications expand and grow in sophistication, I believe we will see an explosive usage of these "physical world hyperlinks"!