Error correction sounds good. It means fewer errors, right? When it comes to QR codes, that’ll mean easier scanning for people, surely? It seems like that’s not the whole story.
I wondered about this, and couldn’t find an answer, so I did some exploration, and found there’s two factors in tension: the error correction on one hand, and the resulting data density on the other:
QR (quick response) codes are now extremely widespread in Australia, because they’re used for COVID contact tracing check-ins and placed in every shop window, but they’re somewhat magic. Before diving into the details, Wikipedia says a whole lot about QR codes; the summary is: a QR code is a pattern of black and white squares that encodes some data (often a URL), that cameras can read.
The article even has diagrams. Here’s one with a whole lot of detail, highlighting a bunch of key concepts going into a QR code, however there’s two that are most important when considering how easy it is to scan a QR code: version and error correction.