As you may have noticed from my avatar, I’m a bit into QR codes. Recently here in Beijing, a type I’ve never seen before has been popping up at many stores. It looks like straight lines of Morse code (- – - – --, for example) radiating out from a central point. The central point isn’t indicated on the code; however, the business logo is in the middle. It also has 3 dots circled, one in each corner (so to speak), and the other corner has a white chain link symbol on a dark background. The whole code covers a circular area. My QR code scanner app doesn’t work on it, but the scanner in WeChat does. Oh, it is definitely not a FaceBook code.
What kind of code is that and what are the advantages/disadvantages compared to the ubiquitous QR code?
Actually, I have the account because it’s necessary for my job. It’s a really cruddy app, IMHO, compared to QQ, which, oddly enough, is provided by the very same company. QQ is better and has more services. But, here in China, “innovative” just means “new”, not necessarily any good.
It sounds like it is a QR code. QR codes don’t have to be square: the elements don’t have to be square: the blocks don’t have to all be valid (it’s easy to insert a logo), the three dots in the ‘corners’ are characteristic of QR codes (and are one of the reasons why the rest of the pattern can be not-right)
Advantages? Sounds like it looks good, and only works properly in the WeChat reader.
It’s interesting though, in that one of the traditional explanations for the success of QR codes in China was that the square code looked like it my mean something as a Chinese character.
ObPedanticNitpick: QR codes must be square, with square elements.
The word you’re looking for is “matrix bar code”, also known as “2-dimension bar code”. Distinct from “linear bar code”, AKA “1-dimension bar code” like the EAN or UPC codes.
2d codes may indeed be non-square.
You may be genericizing “QR code”, which is up to you but technically improper and confusing to those who know better.
The circular Wechat link pictured earlier is definitely no QR code. The question is, what is it? It does not resemble a typical matrix or hexagonal barcode, either.
QR codes are specified to be square. That doesn’t mean they must be square. Code scanners are written to have a high degree of error tolerance and angle independence. I just did a quick test, and I can stretch a QR code to twice the width and still read successfully. Scanners are tolerant of multiple colors, “spots” of varying shapes (rather than squares), and various other distortions.
That said, the WeChat code clearly is something different from a QR code.
Well, the identically placed registration dots say “qr code” to me, but the substantive question has already been answered: the WeChat servers decode the pattern as WeChat “serverless” app identifiers. (The WeChat app sends QR codes home for decoding).
I did try running that image, which does not resemble typical QR codes in the slightest, through a couple of QR decoders, just in case I was missing something, without success.