QR Codes Explained

Introduction to barcodes

QR codes are beginning to gain ground in the UK so I've decided to write an article covering the brief history of barcodes and the lead up to the introduction of QR Codes to give you an understanding of the technology. I've been in IT for 20 years and, as with most technically orientated people, I tend to fall into the 'techie' trap when writing articles explaining technology. The article normally ends up reading like a technical manual for NASA's space shuttle so I've made a conscious effort to stick to layman's terms to make the article clear for a wide audience.

What is a barcode ?

Barcodes are simply a mechanism to capture information without the need to enter letters and numbers at the keyboard and virtually everything you buy these days in supermarkets contain a barcode, which simply contains a unique product identifier. The actual number printed beneath the barcode is the actual number that is encoded within the barcode. The human-readable number is not actually read by the barcode scanner, It's just there for us to quote to customer services departments when you have a issue with a product.
If you quote this number the exact product can be identified when the call center adviser enters the number into their stock system.
Barcodes you see on everyday supermarket items are in a format (symbology) known as EAN (European Article Number) and are classed as 1D (One dimensional) barcodes as the vertical stripes represent a series of numbers.

Barcode on a tin of beans

Previously UPC (Universal product code) codes were used but were slightly too short to cope with the ever expanding amount of goods so an extra digit was prefixed to the UPC code to make it 13 digits and the EAN-13 code was born.

How do 1D barcode scanners work ?

Barcode scanners scan the white space between the black bars . As light is absorbed by darker colours the scanner emits a laser beam across the barcode where the white areas bounce back the light to the photosensor in the scanner.

In reality 1D barcodes could be only 1mm high (the scanner need only scan a horizontal series of strips to decode the information but a very steady hand and lots of patience would be needed to line the horizontal laser beam exactly across the 1mm strips. Making the barcode large just makes it much easier to scan.

History of the Barcode

Way back in 1952 inventors Joseph Woodland, Jordin Johanson and Bernard Silver were issued patent (#2,612,994) for their work based on identifying railroad cars using an Automated Car identification system (ACI, CarTrack). These labels were placed on either side of the rolling stock allowing automatic identification. Their system employed an ink which glowed under ultra-violet allowing the details to be read by a scanning system.

Barcodes began to be commercially used in 1966 with the first UPC code being scanned from the side of a 10 pack of Wrigley's gum at Marsh's supermarket in Troy, Ohio with large scale take up around the 1980’s.

Barcode Symbologies

As more companies began to use barcodes for different uses new types of barcode were introduced to cater for different requirements. Soon barcodes were not only holding numbers but letters too. These variations are know as symbologies. Sample variations include UPC, EAN-8, EAN-13, Code92, Code 128, POSTNET, PostBar, ITF-14 and OneCode out of around 30.

2D Code

When the need to store a lot more information in a barcode arose the concept of 2D barcodes (otherwise known as a matrix code or 2D code) was born. Simply using the existing 1D barcode wouldn’t work if you needed to store 7,000 letters and numbers. (Just imagine the length of the barcode!). The QR code design allows characters to be stored in a format where the data is not identified by a single vertical black strip. Instead, characters can be placed anywhere within a rectangle (information is stored in both the horizontal and vertical directions). As with 1D codes there are lots of variations of 2D codes including QR Code, Color Code, EZcode, Aztec code, Bullseye, MaxiCode, 3-DI, Shot Code and SemaCode out of around 40.

Being able to store a lot more characters than it’s 1D predecessor has enabled the storage of various kinds of information such as Web site addresses, Mobile telephone numbers along with a SMS message, contact cards (e.g VCards), geographic information, plain text and images as well as a host of other information.

2D symbologies cannot be read by a laser beam as there is generally no sweep pattern that can encompass the entire symbol so camera technology is employed.

QR Codes

Denso Wave created the Quick Response code back in 1994 to track parts in vehicle manufacturing (Denso is a member of the Toyota group of companies and is also the patent holder). Unlike some other 2D symbologies that require a license to use the 2D code the QR Code is free to use by anyone. Japan is currently the largest user of QR Codes (QR Codes are the de facto standard for Japanese mobile phones) with Australia and the United states of America heading in the same direction. QR codes started to hit the UK last year (2008) .

How do QR Codes work ?

To enable the mobile phone to understand what action it needs to take when the QR Code is scanned a service type is embedded within the QR code. I’ve listed a few service types currently used to give you a better understanding :-

Service	Example	Instruction
http:	http://www.qrme.co.uk	Browse to a website
mailto:	mailto: This e-mail address is being protected from spambots. You need JavaScript enabled to view it	Invoke an email message
tel:	tel: +44123456789	Telephone a number
sms:	sms: +4407912345678	Send a sms message

Standardisation of QR codes

The Open Mobile Alliance recectly released (Late 2008) a white paper on mobile codes with the aim of developing an open, interoperable standardand (http://www.openmobilealliance.org/Technical/release_program/docs/MobileCodes/V1_0-20081024-A/OMA-WP-MobileCodes-20081024-A.pdf). OMA's visions and background presentation can be found at http://www.openmobilealliance.org/document/OMA_MMF-MC_Final_Presentation[2].pdf. Google have also documented a rough guide to standard encoding of information in barcodes at http://code.google.com/p/zxing/wiki/BarcodeContents.

How can we use QR Codes ?

With almost all of the adult population in the UK owning a mobile phone these days the possibilities for the usage of QR Codes are limitless. McDonalds in Japan are using QR codes on the side of burger boxes which directs you to a web page displaying nutritional information. The film 28 weeks later posted a very large QR Code on a billboard in London recently to promote the film (If it's large enough you could scan it from a mile away!), Harrods of London used QR codes in a recent advertising campaign to attract a tech savvy audience. Safety barriers are being constructed to form QR codes around the corner of Houston and Broadway (New York City, USA) by local artists while reconstruction is underway and Umbro recently included a QR Code on the inside of the latest England football shirt (which takes you to a secret mobile website). Lots of companies are finding ways to use them. A bit of imagination is all you need.

Google charts and QR Codes

If you run a website you don’t need to hire a programmer to spend hours writing code to generate a QR code as Google have added QR code support to their API Charting functions. Ask your website developers to add this one line to your website and specify your mobile website address. This will generate a static 120 pixel x 120 pixel QR Code.

http://chart.apis.google.com/chart?cht=qr&chl=http://www.mywebsite.co.uk/mobile&chs=120x120.

See our web forum for more examples of how to generate a QR code. Note that normal QR Codes will not give you tracking cababilities. You'll have to get this functionality developed for your website.

QRMe service and Goolge map locations

QRMe's QR Codes are trackable, allowing you to see where and when your QRMe Code was scanned in realtime. The QR code contains a pointer to your site profile which specifies yor chosen landing page. Google map locations are plotted based on the IP address of the device which scanned the QR code so may not be entirely accurate as mobile phones without GPS are allocated an IP address of the point of pressence of the service provider (which may be a number of miles away).