You might have seen QR codes that have little graphics or logos embedded in the center.  If you’ve ever wondered how they make these QR codes functional, it’s not some magic formula.  The QR codes just happen to have superfluous data that can be flat out eliminated while leaving the code readable.

Start by getting a code from an online generator such as goqr.me .  The key is to get the largest unused data area possible, so we can cover it up with our graphics.  We do this by selecting a code format that has higher dot resolution, and therefore smaller dots.  Select “Error Correction Code Q” From the options menu, and you will get a QR code that is ripe for logo embedding.

The essential coded dots lie on the perimeter of the QR box, so this only works if you place your graphic smack dab in the center.

To place the image on the code I used Photoshop.  By addind a stroke effect to the image layer, I added a white border around the logo, helping to separate it from the black dots.

Exactly how large you can make your graphic or logo will depend on how long your URL or coded message is. This will require some trial and error.

If you don’t have a smartphone, you can test your code by submitting it to http://zxing.org/w/decode.jspx