Re: Thoughts on current discussion around QR codes

I just looked at the JABCode spec, and while and interesting approach to the problem of finding other ways to encode data – it unfortunately was written/reviewed by people who have no actual understanding of color science and how it is used in today’s world – either digitally or physically.

Given the limited representation of color in the format, it is *impossible* to reliably output and then retrieve the colors, especially across their intended use case of digital->analog (aka print)->digital.


From: Christopher Allen <>
Date: Sunday, February 16, 2020 at 6:38 AM
To: Credentials Community Group <>, W3C DID Working Group <>
Cc: Wolf McNally <>, "" <>
Subject: Re: Thoughts on current discussion around QR codes
Resent-From: <>
Resent-Date: Sunday, February 16, 2020 at 6:37 AM

If you want to use an optical or RF data carrier, you will be limited by
the capacity of that system. If the data you want to convey exceeds that
capacity, you need to reduce your payload, use a higher-capacity data
carrier, or both. There are higher capacity optical data carriers. In
particular, JAB might be relevant [5]. That's basically a QR code that
uses colour to increase the capacity and is on its way to being an ISO
standard. My colleagues in China are behind another bar code, Han Xin
[6], which also has a higher capacity than QR.

Please jettison, forget, and generally bury the idea of an animated QR code.



Here is the reference DID in Jabcode and in iso 69321:

Received on Sunday, 16 February 2020 13:40:04 UTC