⚡ Making QR Code Art - Felix B

QR Codes. How do they work, and how can we alter the generation algorithm to get almost any pixel art we want, while making sure the link is still valid? The answer? Maths, and lots of it. But also some interesting masking and error correcting techniques, which is what we'll discuss.
Talk by Felix B.
Blog Post: research.swtch...
Demo: research.swtch...

[@probablykeegan]

Time to find out if any of these QR codes link to a certain dQw4w9WgXcQ

[@TheRustyCrab]

that has to be the most memorized string of letters and numbers on the planet 💀

[@eldattackkrossa9886]

this is very cool, now i wish i had some occupation where i have to use qr codes so i could use custom ones

[@peterkilian9100]

I want to go to this university

[@tutacat]

happy birthday keegan

[@Imperial_Squid]

"Luckily the QR code spec lets us smush two formats together"
Fucking WHAT?! Why was that ever implemented?? Don't get me wrong, I'm thankful it is, it's very useful but what bizarre niche use case was the motivation behind that idea??

[@Imperial_Squid]

Also, brb, making a project where you can feed it an image and some text and it'll auto solve for a valid QR code

[@warwickcomputing]

I hope you like linear algebra

[@felixbee]

Good question... Since it was originally made to label machined parts, perhaps they had a system in mind where part of their codes were alphanumeric and part were solely numeric? So that they could minimise the size of the resulting code. Can't say for sure though.

[@mergenstudios8779]

lol that was good

[@lithium534]

So let me get this strait, If I generate a QR code with a 30% redundant error I can remove the center section and it will still work? So by using the masks I can delete whatever it masks.
So many question from this.... I would really like to know how much can be removed and still be detected without trial and error for every square.

[@edgeman1135]

Reed-solomon codes can actually detect which blocks are incorrect when the number of mistakes is less than 50% of the redundancy. There's a bit of bruteforce to find the number of errors, but that's nothing compared to going over all combinations.

[@jamariobeard7213]

How u use logo n QR code to website

[@OnlyTheQuack]

Is there a tool to make these?

[@warwickcomputing]

There's a tool to generate smaller ones (check the description), although we haven't found any online (yet) for the larger QR code versions like v20 and up - might try and see if we can make one ourselves unless someone beats us to it

[@Jason9637]

​@@warwickcomputing Is that a challenge?

[@v0xl]

​@@warwickcomputing there's also one that does color and arbitrary size qr codes
looks pretty cool

[@funkeypigeon]

First!

[@RockyBee]

Fifth!

[@clehaxze]

This should have been submitted to SIGBOVIK. Will be an absolute blast