QR codes in 4 qualities and error corrections
From your zumoQR account you can generate QR codes in four different qualities, depending on their use.
QR codes can be made in different sizes depending on the amount of information to be displayed.
QR codes utilize the so-called Reed-Solomon error correction to ensure the system’s robustness with regards to errors in the scanning/reading (damaged or dirty barcodes and the like).
Four different qualities/levels are available to transmit the correct information even if parts of the code cannot be read correctly.
Level L can recreate 7%, level M 15%, level Q 25% and for level H the number is 30%.
This error correction has led to the creation of QR codes / barcodes with intentional “errors” in the form of including little images, logos or similar in the middle of the pattern of black and white squares.
The human eye can easily “crack” the bar code pattern when these images are included, but the code can still be scanned without problems.
Tips for use
If your QR code is being displayed on a small surface (such as the screw-top cap on a soda bottle) we suggest using a 7% code as the higher qualities in this size will be too cramped and thus difficult or impossible to scan. Avoid including images or graphics in these. If you have more room to work with, you can choose a higher quality – and if you wish, include a logo in your QR code.
Note that you cannot change the quality after you have generated the QR code.