Over the past year or two, you’ve doubtless noticed QR codes – little squares of seemingly random black-and-white pixels – cropping up more and more on posters, leaflets and other media.
A QR code (short for “quick response”) is essentially a descendant of the barcode, one that can carry all sorts of information, such as a phrase or a web address. It’s also a system that’s been seized upon by marketeers and advertisers across the world as a means to further engage audiences. When an interested passer-by sees one of these codes embedded in a regular advert, they can scan it with a smartphone and be instantly directed to a site offering more information or streaming media.
This is far from the only use for QR codes, however. In fact, it’s a poor fit for the technology. When a member of the public is walking – or driving – down the street, it’s inconvenient, and quite possibly unsafe, for them to stop to scan a code. Happily, there are many more creative and practical uses of QR codes – and some other pitfalls to be aware of.
QR codes may have limitations as a mass medium, but they can be useful at a personal level. For example, while it’s possible to encode a telephone number in an old-fashioned (“1D”) barcode, it’s hardly worth the effort. With QR codes, it’s possible to encode a complete business card’s worth of data in vCard format, like the one we created at goqr.me
that you see at the top of this article. Print this code on your business card, and the recipient can simply scan it to automatically add your contact details to their digital address book. Alternatively, a QR code can send them directly to a professional page, such as your LinkedIn profile.
Creating a suitable QR code for a business card is straightforward. There’s no need to install any software – you can simply use a free online code generator, such as the one offered by the ZXing Project
At this site, all you need to do is select what sort of data you want to store (in this case, contact information), enter the relevant details and click “Generate”. You’ll see your custom QR code appear on the page. Click the download link to save this graphic, add it to your design and hand it out to colleagues.
If you use an online business card printer the company may even be able to produce the QR code for you. But if you produce your own code, you have the option of customising it, to make it stand out and look more aesthetically attractive. See our walkthrough on p85 for a guide to prettifying your codes.
Embedding messages & codes
In the above example, we used the ZXing generator’s default “contact information” setting, but if you click the dropdown you’ll see there are many other types of information that can be stored in a QR code.
One interesting possibility is embedding a formatted SMS text message in a QR code. Whenever someone uses a smartphone to scan the code, they’ll be presented with a text message, already written and addressed (but not automatically sent). This has all manner of possible practical uses. For example, you could print out a code and affix it to your key ring: if you ever lose your keys, anyone who finds them might scan the code and send you a message to help you collect them.
Another lesser-known use of QR codes is to share your home Wi-Fi login details with visitors using Android devices. This will allow them to connect their smartphones and tablets to your wireless internet connection, without you having to painfully spell out the exact sequence of letters and numbers that makes up a secure password. Given that WPA passwords can be up to 63 letters long, this can be a real time-saver, especially if you change your passwords as often as you should.
Again, such codes can be created with the ZXing QR code generator. Choose “Wi-Fi network” from the Contents dropdown and enter your router’s SSID, encryption type and password. Click Generate to produce a code, which you can then stick somewhere secure for visitors to scan. If they don’t already have a scanning application that supports this type of content, they can download one for free from Google Play: one such option is “Barcode Scanner” by the ZXing Team.
Once your friends are online, you can also use QR codes to share weblinks and other information between mobile devices. Link-shortening services such as bit.ly
and Google’s goo.gl
can automatically create QR code shortcuts to web addresses. In both cases, this is achieved by generating a regular short URL, then appending “.qr” to the end of it – so “http://bit.ly/p8Yiz7” becomes “http://bit.ly/p8Yiz7.qr”.
Google’s service is particularly handy for businesses and bloggers, since it keeps logs of clickthroughs: you can see how many people have followed your QR code and when, broken down by country, browser and operating system.
You can share more than funny videos using QR codes. With services such as TagMyDoc
, you can share digital copies of physical documents and presentations. Include the appropriate QR code on the printed page and others can scan it to access a downloadable or online version.
Of course, this can be achieved without involving a third-party service. It’s perfectly possible to host your own files online, and create a QR code yourself that points to the download address. Indeed, if you’re intending to customise the appearance of your QR code, as we demonstrate on p85, it’s the only option available.
Personal uses for QR codes can draw inspiration from business, too. A recent US campaign by jcpenney invited customers to create personalised voice messages, which could then be embedded in QR codes and attached to gift items. When the recipient scanned the code, the message was played back, adding a personal touch. There are several free online services that can do the same: QR Voice
is one that doesn’t even need you to record the message. Your message is spoken aloud on your behalf, using a synthesised voice borrowed from the Google Translate service.
But why stop at audio? If you have a webcam, then it’s just as feasible to upload a short video to YouTube and embed its web address in a QR code. When scanned with a smartphone, the code will automatically forward the phone’s browser to your video, for you to deliver your message.
Before you start reducing your entire life to a series of boxes, remember that QR codes have hidden hazards.
From a user’s perspective, the big danger involved in scanning QR codes is that you never know where an embedded link may lead you. You could get a nice surprise, as has been the case with graffiti artists adding QR codes containing local history lessons to derelict buildings. But it’s just as possible that the code could take you to a compromised website that tries to install malicious code on your device. Such attacks aren’t common, but you can’t afford to be complacent.
There are important considerations for QR code creators to bear in mind, too. To the human eye, QR codes may appear to mask information; but to anyone with a smartphone or tablet they’re completely transparent. If you’re using this method to share your Wi-Fi details, you must ensure that the code won’t be seen by anyone you’re not happy to have connecting to your network – and make certain that it isn’t visible from outside of the house. You might consider using an app such as QR Droid on Android, which layers 56-bit DES encryption onto the code. Scanners will be challenged with a question that must be answered correctly before the encoded content can be accessed.
Similarly, companies such as Scan Me
offer services whereby you can print codes onto T-shirts, badges and more. Before buying in, consider whether you’re really comfortable transmitting the embedded data to everyone around you. (And remember, too, that even if you do want your address on your T-shirt, you may not be comfortable having cameras regularly pointed at your chest.)
The location of your QR code can be problematic in other ways, too. Travellers on underground railways see plenty of posters and advertisements sporting QR codes, intended to direct scanners to official sites or downloads. But since these codes are, naturally, underground, it’s impossible to follow them there and then.
There are also presentational matters to consider, especially if you’re using QR codes for business. If you produce a card or leaflet that uses a QR code to direct the reader to important information, remember that a significant proportion of readers won’t bother to follow it. If you don’t provide clear instructions, many may not even recognise what they’re expected to do.
It’s also crucial to ensure that your QR code leads scanners to the right place. Double-check your embedded data: a single spelling slip could send scanners to the wrong site, or turn your personalised message into a Rickroll.
Since the quality of smartphone cameras varies wildly, you should also make sure your QR code is large and clear enough to be readable even in unfavourable conditions – TV ads have certainly not proven successful.
Designers can adapt QR codes, but they'll still work
Readability problems are especially common with larger codes – that is, those containing larger quantities of data, and hence requiring more pixels. As the pixel density goes up, so the relative size of each pixel goes down, making it harder for the scanner to read anything.
Ironically, one way to improve readability is by employing less error correction. QR codes are encoded using a Reed-Solomon error correction algorithm (as also found on DVDs and CDs), which means the code will still work even if a certain amount of data is obscured or corrupted. This useful ability doesn’t only give QR codes resilience against blotches and tears: it also opens up the possibility of customising your codes in ways that obscure some of the data, as we discuss in this article.
The level of error correction that’s applied, however, is customisable. When you create a code, most generators will allow you to choose from four levels of correction, dubbed L, M, Q and H. These levels offer protection against corruption rates of 7%, 15%, 25% and 30% respectively: but they also add complexity to the resulting code, resulting in more, smaller, harder-to-read pixels.
For this reason, it’s best to use Q or H only when you’re sharing small amounts of information, such as a single web address, as this will still leave the pixels large enough to be easily read. If you’re encoding a greater amount of information, such as a passage of text, it’s a good idea to drop down to M, to strike a balance between protection and readability.
There's an app for that
Surprisingly (and annoyingly) neither Android nor iOS includes a built-in QR code scanner. And although BlackBerry Messenger can read QR codes, it doesn’t support the full range of data that can be embedded. Happily, there are plenty of free and paid-for apps that can do the job.
For Android, check out DroidLa’s QR Droid
. It’s easily one of the most comprehensive QR suites on the platform, letting you scan with the camera, decode from saved images, or manually key in data from 1D barcodes. It also reads Wi-Fi details from QR codes, and includes sharing options through social networks. The free version is ad-supported, but that hasn’t stopped it becoming the most popular scanner on Android.
On iOS, one of the fastest and simplest QR scanners is Tap Media’s QR Reader for iPhone
. It works on the iPad, too, and although it’s free it doesn’t bother you with pop-up ads or the like. It includes a QR scanner, an integrated web browser and sharing tools, plus a QR code creator.
Finally, for BlackBerry users, 3GVision’s i-nigma reader
is a straightforward, free option. It lacks some of the functions of comparable apps on other platforms, but the latest version includes built-in sharing tools, as well as an option to type in data manually for decoding 1D barcodes.
A Microsoft tag
The term “QR code” is popularly used to refer to all types of 2D barcode – that is, barcodes that encode their information in a matrix of pixels, rather than a series of vertical stripes. Technically, though, it refers to a specific format originally developed by Toyota subsidiary Denso Wave – and there are several other types of 2D barcode that you might run across.
By far the most popular alternative to QR codes is Microsoft’s High Capacity Color Barcode system, branded as “Microsoft Tag” (pictured). This system uses coloured patterns, and can support customisable backgrounds, allowing more interesting designs than are possible with QR codes. A lack of visual consistency, however, makes Microsoft Tags less iconic and recognisable than QR.
The Digimarc Discover system is targeted at professional advertising, and works by embedding augmented reality content into images, using watermarks invisible to the naked eye. When these are scanned by specific apps, interactive video or similar content is revealed. The technical demands of the system, and the need for supporting software, however, has seen Discover get off to a slow start.
Data Matrix codes look a little like QR codes, using black-and-white pixels to represent binary data, with an L-shaped border to help scanners locate the code. Similar error-correction systems are employed to improve readability if the barcode is damaged – a common hazard in the military, aerospace and electronics industries where Data Matrix coding is to be most commonly found.
WALKTHROUGH - Create a customised QR code
QR codes are normally rendered as plain black-and-white matrices; but it’s possible to colourise a code, and even decorate it with a custom logo, to make it eye-catching, while keeping the embedded code readable. In this walkthrough, we’ll encode sample text from the PC&TA website, and liven up the QR code with a graphic.
To generate the basic QR code, we’ll use the ZXing generator. From the top dropdown, select Text and paste in the target text. Choose a level of error correction: more correction results in a larger code that can be harder to read, so we chose M (15%). Click Generate to produce the code.
There are some areas of a QR code that mustn’t be meddled with, or it may not be recognised. These include the three black squares in the corners of the code, which are used to locate the data, and a white area surrounding the box on all sides. Here you can see the same code twice, with the right image highlighting “no go areas”.
An easy way to customise is by superimposing a graphic. This must have a white border, and it can’t be too large, or error correction won’t be able to recover the data it covers up. To calculate the maximum size a square image can be, divide the width of the code in pixels by 100, then multiply by the error-correction level.
Colour contrast is vital for a readable code, but that doesn’t mean it has to be black and white. You can apply a custom colour scheme, so long as the dark data modules are all significantly darker than the background. In this example, we’ve used the GIMP to overlay a recognisable image onto the dark areas of our code.
You can combine these methods, of course, but the more alterations, the more critical testing becomes. Here we’ve just added the PC & Tech Authority logo onto our QR code, creating something more eye-catching but not confusing. We’ve also anti-aliased the image, softening the edges of the data blocks to create a gentler effect.
[Main article image: http://goqr.me/]