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    It doesn’t explain the fun stuff (error correction).

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      It’s something I’d like to write about, reed solomon codes are incredible. Most technical presentations on it peruse rigorous definitions on bounds and theory and it isn’t too accessible.

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      More cool QR code stuff: https://research.swtch.com/qart

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        And even more QR code tutorial: https://www.thonky.com/qr-code-tutorial/

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          The idea of strapping a QR code onto an airplane is fascinating. I wonder if it was readable from a phone on the ground, with wind blowing it around and the perspective distortion..?

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          For a UChicago scav hunt one year, a friend of mine had to learn how to read QR codes. He told me that once you get over the first dozen humps, humans can translate them surprisingly quickly!

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            I can believe that. I once sat down with a pile of mail and basically stared at it until I could read the USPS barcodes. Ever since then, it’s almost annoying how easily my brain processes it. But that itself isn’t far off from how people can learn to think in Morse, for example: brains are amazingly willing to “natively” handle binary codes, whether visually or aurally, as long as they’re trained in it. At this point in my life, that’s not a surprise anymore.

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              I enjoyed the article, very nicely explained with reasonable diagrams. Thanks for posting it here. :-)

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                This is really cool! I saw the thread on Twitter too, the diagrams are great!

                One thing I do want to learn though is the bit between pixels and the QR format, how does it scan the image and find the patterns and orientation etc? That would make a cool explainer!

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                  Great little article. Thanks for posting!

                  We use Nayuki’s QR library. We published our tweaks as a Javascript fork here: https://cyphrme.github.io/qrgenjs/ edit: and we just added a link to this article in the README. Thanks!

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                    I used QR code knowledge to create a magic QR code! Eventually it does cool things!