in QR Codes and Augmented Reality
QR CODE EXPERIMENTATION|
How Much Contrast Does a QR Code Need?
Did you know you can modify QR codes creatively and still maintain their ability to be scanned? We decided to experiment to see what we could get away with.
We were intrigued by a Mashable.com story discussing design modifications of QR codes. As you may be aware, there is a built-in error-correcting system in a QR code, so that even with an up to 30% degradation of the bar code, it can still be, at least theoretically, altered. The Mashable story shows some examples of designers using a trial-and-error approach to jazzing up QR codes, changing them but not enough to ruin them.
First, we placed a small version of the Coca-Cola logo in the center of the QR code. We were able to get it to scan at about 20% of the size of the QR code.
This got us thinking: What about screened back image overlays? Put another way, how much contrast does there need to be between a QR code's black bars and white background? It turns out, at least on our Android built-in bar code reader, the answer is 60% is a sure thing, but some tricks allowed us to minimize the QR code, and maximize the image.
To test the requirement, we began with the iconic Coca-Cola logo and the QR code for http://www.coca-cola.com and started testing how much we could increase the impact of the logo while minimizing that of the bar code, while still getting a clean scan.
The image above represents a 100% background of the QR code, with a the Coca-Cola logo as a Photoshop layer above the code, set to normal with 40% opacity.
We then switched the order, putting a 100% Coca-Cola logo behind the QR code, set to normal with 60% opacity.
Finally, removed the white from the QR code via a selection, set the background Coca-Cola logo to 80% (on top of a 100% white background), and set the foreground QR code to normal with an 80% opacity. Note that this version is a good example of why testing is so important. It initially scanned fine with the Bar Code app on an HTC Slide phone, yet would not scan with some third-party QR code apps, such as ScanLife running on the HTC EVO.
Note that these merged images, while interesting, took an average of three times as long for the bar code application to recognize them than the original QR code represented above.
This isn't a scientific study, as we tested the ability to scan with just one middle-of-road phone with one scanning application. It may give you some ideas on what you can achieve, however. That's all we set out to do.