'QR is cool' is a website that shows how excellent QR code error correction is, and QR codes can maintain their original information even if they are significantly altered.
QR codes have
App | QR is cool
https://qris.cool/
QR codes have four error correction capabilities: Level L, Level M, Level Q, and Level H. Level L allows the original information to be preserved even if a maximum of approximately 7% of the code is lost, Level M allows a maximum of approximately 15% of the code, Level Q allows a maximum of approximately 25% of the code, and Level H allows a maximum of approximately 30% of the code to be lost.
QR is cool is a website where you can read a QR code and then experiment with 'finding the limit at which you can rewrite part of the QR code and retain the original information.' You can use pre-prepared QR codes for your experiment, or you can use a QR code you've scanned with your own device. This time, I wanted to scan a QR code with my iPhone camera, so I accessed QR is cool on my iPhone and tapped 'Scan a QR code' at the bottom of the screen.
When asked for permission to use the camera, tap 'Allow.'
When the reading screen appears, read the desired QR code. In this example, we read the QR code that can access GIGAZINE (
When the QR code is read, it is converted into a QR code that conforms to the specifications for expressing 'https://gigazine.net/'. The error correction capability of this QR code is 'Level M', which means that it can be read even if up to 15% of it is missing. Tap 'Continue' at the bottom of the screen to move to the experiment screen.
The experiment screen looks like this.
If you tap anywhere on the QR code, the part you tapped will be rewritten. If you only rewrite a few pixels, the information 'https://gigazine.net/' can be read without any problems.
Even if you keep rewriting it, it can still be read as 'https://gigazine.net/'.
When 3.6% of the code was rewritten, it was no longer possible to recognize that it was a QR code representing 'https://gigazine.net/'. In this way, by using 'QR is cool', you can experience the excellence of the QR code's error correction ability and challenge the task of 'finding a way to rewrite as close as possible to the theoretical value of 15% error correction'.
By the way, QR codes were developed by Denso, an auto parts manufacturer, in 1994. The following page summarizes the development history of QR codes and the reason why the cut-out symbol is a rectangle.
Journey | QRCode.com | DENSO WAVE INCORPORATED
https://www.qrcode.com/history/
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in Review, Web Application, Posted by log1o_hf