Did you know that QR codes have the highest reading? It’s a fact!

How does a terminal decrypt a QR code? The three corners, with their squares, are references to allow the barcode reader to identify and align the code. Of course, the empty area around the code facilitates the work and allows the bar code reader to distinguish the code of the background image. But even without these elements, the reading rate remains high, and the QR code is read in the majority of situations.

The secret of this reliability is the Reed-Solomon algorithm, which corrects the errors of reading according to four levels.

  • Low:  7% of the code can be restored
  • Medium: 15% of the code can be restored
  • Quartile: 25% of the code can be restored
  • High : 30% of the code can be restored

The higher the percentage of errors the code can correct, the less data the code can contain. It is, nevertheless, a very interesting way to minimize errors in readings. Up to 30% of the codes can be restored with this algorithm, in other words, the QR code must be highly altered for its reading to be impossible.

In this article from the blog DataGenetics, a researcher ‘abuses’ a QR code (with a 30% error tolerance) by altering the contrast and color, by adding blur and noise effects. The result;  the vast majority of the QR codes were still readable, despite the distortions and alterations. Some readers were able to read all the damaged codes with their smart phones!

For a barcode to be unreadable, the alterations would have to be extreme. Of course, the quality of the reader also plays an important factor. The researcher in question used his smart phone, which means that with a more efficient bar code reader (such as Cognex DataMan readers, for example), it is possible to achieve 100% of read codes, and therefore, save time and money by eliminating reading errors. If the QR code is not indestructible, it remains one of the most reliable and effective methods!