A look at 2D bar-coding

Have you noticed over the last few weeks in the dead-tree version of Network World there has been a section that displays a curious pattern of dots and invites you to direct your cell phone’s Web browser to http://wap.connexto.com?

That dot pattern is a proprietary 2D bar-code format developed by Nextcode called mCode. 2D bar codes are much like regular 1D bar codes except that they encode data in (du-oh) two dimensions.

The advantages of 2D bar codes (also called stacked symbology or multi-row codes) are that they support a broader range of data representation and a greater data density than 1D bar codes. On the other hand 2D bar codes can’t be read by regular laser-scanning systems — they are typically captured and read by a camera. And what common devices have cameras? You got it in one! Cell phones.

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Have you noticed over the last few weeks in the dead-tree version of Network World there has been a section that displays a curious pattern of dots and invites you to direct your cell phone’s Web browser to http://wap.connexto.com?

That dot pattern is a proprietary 2D bar-code format developed by Nextcode called mCode. 2D bar codes are much like regular 1D bar codes except that they encode data in (du-oh) two dimensions.

The advantages of 2D bar codes (also called stacked symbology or multi-row codes) are that they support a broader range of data representation and a greater data density than 1D bar codes. On the other hand 2D bar codes can’t be read by regular laser-scanning systems — they are typically captured and read by a camera. And what common devices have cameras? You got it in one! Cell phones.

The Connexto software, which supports a wide range of cell phones, is made available for free by Nextcode, and the supported cell phones include models from LG, Motorola, Nokia, Samsung, Sanyo, Sony Ericsson and Siemens.

Once you have registered on the Connexto site (also free) you can click on the Code Creation tab and generate mCode “codes” as bitmapped or Encapsulated PostScript images. Note that the Connexto site requires that you run Internet Explorer because the mCode code generator is an ActiveX control.

Obviously, committed Firefox users and the entire Macintosh community are excluded from the fun, which is obviously not necessary as the generator software could easily have been server-based and (ideally) use an AJAX client side or, less easily (but potentially more sexily), implemented as a Flash movie. Of course, the guys at Nextcode forgot to ask me so what can you expect.

While I’m at it, let me digress for a moment and point out something that should be blindingly obvious: Any company that limits its market by artificial and unnecessary technical constraints is making a big mistake. While you might develop a following you will always be vulnerable to losing out to any competition that addresses a broader market even if they have an inferior product.

Anyway, the content of a code can be a URL, an SMS message, contact data or an auto-dial telephone number. To use a code, whether it is printed on something or shown on a display, you simply point your camera at the code. Once the image is acquired and decoded by the Connexto software it will ask if you want to allow the cell phone to perform whatever action is called for. You can also save the code for later use using the Connexto software.

The mCode format has some interesting qualities: It can be read in any orientation and at fairly large angles from the normal (i.e. directly facing the code). You can change the overall size of a code but not its aspect ratio, and the recommended minimum resolution is around 20 dots per inch (20 modules, as Nextcode oddly terms them), which ensures that most cell phone cameras can get a full frame image with adequate detail.

You might think that RFID will render 2D bar codes obsolete but in cost-sensitive applications (such as in magazines), in harsh environments (say, pipe labels in a chemical plant), or where distance is a factor (for example, on billboards) they will always be effective.