Damaging QR Codes to Create Circles: Are Corners Necessary?

I am trying to create a circular QR Code. I understand that the typical circular codes require customer readers (Facebook, Kik, TikTok, ShotCode, etc.), but I would like this code to be able to be read by standard devices (ex.: the built-in reader in iOS devices).

I have looked at a stack of reference materials, including:

I've also dug into the (really in-depth) tutorial at thonky.com, and tried to create my own:

From what I can tell, I've kept the finder patterns, the alignment pattern, the timing patterns, the separators, and the dark module intact (see details here). But still no love when I try to read it.

Admittedly, I've taken an existing code (it contains the URL 'https://www.stackoverflow.com') and just chopped off the corners to make it fit. So my assumption is that I've damaged the code enough that the error correction isn't working.

But, would this work at all anyway? If I figured out how to encode it correctly, would it work without the corners? Or is this a useless endeavor to start with?

Solution

There is a basic structure for QR codes with specific elements that take part in the decoding process. Some of them are the alignment, the timing pattern, and the finder pattern. One of the elements which seems to be missing is the quiet zone. It's used to separate the code from other objects and surrounds all the data including structuring elements in the code. Have a look on the outer side of codes here and notice the difference. Also, if you look at the points that represent your data cells, some of them partially exist. In other words, some half and quarter circles exist and others are unknown behind the outer frame of your code design. How would it be figured out if it's black or white to be used for decoding? This is the problem. Please check this image to see how data look missing when you crop it with the circle.

Also, if you use any regular QR coder reading application, you will notice that circular QR codes require custom readers. So, the answer to your question is yes. The corners are necessary if you don't use a custom reader and if data exists on them.

If you are interested in academic research details, see this. I hope my answer helps you. :)