Definition of a QRcode in a QRcode

By Andrew Davidson
on January 24, 2010

This barcode is an ISO standardized 'QRcode' (QR is short for 'quick response'), developed by the Denso Corporation to squeeze more data into a small area. It's strengths include high-speed reading, high capacity & density and error correction!

Scan a QRCode with your iPhone

You'll need the free Barcode for iPhone to read it. Since the iPhone's camera isn't the best, I find taking a photo from a few feet away, then scale to fit before 'reading' it helps. Barcode for iPhone uses an open-source QR decoding engine, and prompts you before doing any scanned action, including going to the URL calling the phone number, or emailing the subject. This way you can determine if you want to pursue the action.

A bit more about QRcodes

QR code started to take off in marketing/consumer space to bridge the gap of online and offline since 2000. Today, it’s so prevalent in Japan that you can find QRcodes everywhere, even graves. I think this is one Japanese invention that will soon take over the United States as well! Imagine being able to scan a QRcode off the front of a restaurant, and get real-time reviews as well as a coupon for a meal at that same restaurant!

Since you can pass so many types of information, including plain text (as seen above - maximum 250 characters), a URL, a phone number, or even an SMS message. This site, while it's english is poor, has a very good breakdown of the technology and encoding of a QRcode, as well as open-source computer code for creating your own. I found it very informative when it comes to determining what's data, and what's error-correcting. In the above embedded example, you can see the three larger squares in the corners are 'landmarks' for the data to be read. There's also a sub-grid of smaller squares for bit-level encoding, and (it's hard to tell) there's a dotted line between the larger dots inside corners, used to track the data above and below it (something like a parity bit...)

Want that instant gratification? Create your own QRcode here from Kaywa. They also offer a free QRcode reader for certain supported mobile phones (maybe yours!).

I'm thinking of deploying QRcodes as part of a street-art project. Possibly offering free downloads (wallpapers, ringtones, coupons), or thought-provoking content when people scan the codes. One implementation would be tying a web-enabled video camera to a QRcode, so that when you scan it and go the resulting URL, it'll show you a live picture of you scanning the QRcode. I imagine the result will be a bit 'Big Brother' creepy-like, if not a novel way to track cellular IP's as they are scanned. Also, by using a URL shortening service, you can mask the server from basic counterattacks or improper use.