In the past three posts of our “barcode types” series we’ve looked at the difference between 1D barcodes and 2D codes, but also illustrated the differences between different 1D and 2D symbologies.
Today, we want to conclude this series with some futuristic and entertaining barcode formats. Before, let’s discuss what these codes have in common: None of them see widespread use today and they all originate from the need to store more data than you can store in other two dimensional codes such as QR codes. While the QR code only covers 2 dimensions, namely height and width, the codes in this post use a 3rd (color) and even a 4th dimension (time). And last but not least we’ll quickly introduce an innovative LED-based 2D code.
Be it the Microsoft tag (as discussed in the previous post) or other colored 2D matrix codes, the use of color significantly expands the data capacity of such a code. In binary codes we discussed before, there were black and white elements only, representing 1’s or 0’s each. Now, with additional colors, one single point in a matrix code can represent 10 or even more values, depending on the robustness and the sensitivity of the scanning system.
Time & color: 4D codes
Now, if colors are not enough, how can you increase data capacity even further? By changing the symbols over time. Changing the symbols over time also means that the number of symbols in a code at one particular time can be reduced – a convenient way to reduce the size of codes.
The downside of these time-varying codes is that they cannot be printed on paper and are limited to device-to-device communication. They are thus also competing with wireless communication technologies.
This optical identification technology was developed by the MIT Media Lab and can hold significant more data than other existing codes. Powered by a LED and covered by a mask, they are arranged as a collection of multiple Datamatrix codes within a lens of 3mm size – impressive data storage capacity for such a small area.
Its strength lies in its capability to dynamically modify the stored codes without the need to produce a new tag. Since Bokodes are not simply printed on paper but feature electronic components such as a lens and LED, Bokodes are rather expensive and not yet ready for the mass adoption.
But why have none of these barcode types seen widespread use?
- Niche use cases: the high data storage capability is not required in many applications and the mobile network can provide a decent alternative to download large data packages.
- Cost: Time-varying and LED-based codes cannot be printed and are thus expensive.