The humble barcode - named for its ability to encode information in a series of machine readable bars (or lines) - began its life in 1948. Nowadays all manner and style of barcodes exist, so let’s take a quick look down memory lane and see how the barcode has evolved over the years, and how they work.

History Of The Barcode

The idea of a barcode began in 1948, when a graduate student overheard the president of a local supermarket chain asking for a way to automatically read product information at the checkout. He began experimenting with a variety of systems, the first of which used ultraviolet ink - which was expensive and faded easily. Convinced the idea was workable though, the next version involved extending the dots and dashes of morse codes downwards; a bright light was then used to project the information on a photomultipler tube (which "amplifies" light).

Oddly, they then decided it would work better if presented as a circle, to allow for omni-directional reading; but they nevertheless patented both. After moving to work for IBM in 1951, one of the co-inventors attempted to get their interest in the patent to develop it, but IBM concluded that the technology needed would be a while away. The patents was purchased by Philco in 1962, then sold to RCA (Radio Corporation of America).

Concurrently in 1959, another barcode-like system was being developed to help identify train carriages - using a series of blue and yellow reflective bars - but with poor economic conditions it wasn’t until 1974 that most of the railroad fleet was labelled, and the system was eventually abandoned in the late 70s due to technical difficulties. In 1967, the lead engineer on the railway project broke away to form Computer Identics Corporation, which began work using lasers and a scanning mirror to identify and locate a barcode up to several feet in front of a scanner.

The barcode as we know it today was actually the result of many competing systems. In 1966, the National Association of Food Chains began to seriously investigate the idea of using barcodes, eventually setting out guidelines on univeral product codes in the mid–70s, and approached various companies developing barcode technologies at the time to submit proposals and tests. After some technical problems with ink running over on the circular type codes, IBM’s linear standard was chosen, and the barcode as we know and love it today was standardised and rolled out.

The first item to ever be scanned was a pack of Wrigley’s Fruity Chewing Gum, on June 26, 1974.

Tough Early Days

The machines to read barcodes remained expensive and prevented widescale adoption of the system for a long time; it was pronounced a failure after a few years. Conspiracy theorists believed barcodes to be a form of intrusive surveillance (probably foreseeing the loyalty card phenomenon), while extremist Christians pronounced it the work of the devil, with codes hiding the number 666. However, adoption did continue to grow - by 1980, 8,000 stores per year converted to the barcode system.

How Do Barcodes Work?

In todays systems, a laser will scan across the length of the code, detecting how much of the light is reflected back at any one time. A white surface reflects more light than a black surface, so the laser can easily separate and read the dark and light areas.

One-dimensional barcodes - the ones that consist of lines and whitespace - all work essentially the same way even though they may be different standards for encoding more or less information; they all use binary numbers - just like a computer. Here we’ll only be looking at Universal Product Codes - the kind you will find on anything you buy, all over the world. It's this universality which means you can scan the barcode of a product using any of hundreds of mobile apps, and perform an instant price check on Google or Amazon.

Every barcode can be divided up into equal spacing (in the video below, 95 parts to be exact). With black representing 0 and white representing 1, we can see how a barcode is just one long binary number. Now, remove the front and rear 3 bits, and the central 5 bits - these are markers to indicate the start and finish of the code and to aid with alignment, and then break the rest into 12 sections - that is, 12 different numbers that form the actual code hidden within.

http://www.youtube.com/watch?v=e6aR1k-ympo

Watch the rest of the video to see a detailed breakdown of the codes involved. As you can system, the system is resilient in some ways (it doesn’t care about the direction it scans), yet quite fragile in others (a small smudge or a marker pen on one line would break it completely).

Evolution Of The Barcode

As scanners became more able to detect detail, and highly accurate digital cameras became the norm, the barcode also naturally evolved - instead of just 1-dimensional lines, 2-dimensional patterns inspired a variety of independent system - the most famous of which is the QR-code (pictured bottom-center).

QR-codes were created in Japan by Toyota, for the purposes of high-speed tracking of car components during assembly. The technology was soon expanded to Japanese consumers, where mobile phones were far more advanced than their western counterparts for a long time, with full featured cameraphones and apps to read the data contained in QR codes.

It’s no secret among MakeUseOf writers that I despise QR codes on magazines and flyers. At best, they complicate an already short web URL into something that’s just fiddly to use; at worst, they’re a great way to get malware, or be redirected to phishing and disgusting shock sites. I suggest you read Justin's hilariously sarcastic take on why QR codes are so awesome (and there I was thinking only Brits could do sarcasm properly), or Tim's genuine article on QR-code uses.

If we simply look at 2D barcodes as the evolution of the 1-dimensional barcode, it’s easy to see how they can be applied in a business context; they hold more information than a barcode, and that’s useful. Whereas barcodes would invariably hold an ID number, used to reference a database and retrieve additional information about a package (like destination, weight, contents etc), a QR code can hold all of that on the package itself. Variations of QR-codes will continue to be used within a business context for the immediate future; have a look on your next Amazon parcel or UPS shipment.

You now know how barcodes began, how they’ve evolved over the years, and a little of how they are useful today (or not, as the case may be). Do you have anything add that you think I might have missed?

Do you use barcodes or do regular price checks on your mobile? Do you honestly see a future for QR codes within the consumer space? Let us know in the comments!

Image Credits: Zephyris, Wikimedia Commons