Gregory's Server
 65 comments
@saper @blinry @piko If you understand German, perhaps have a look at https://www.arminhanisch.de/2018/10/qr-codes-lesen/QR-Codes-lesen.pdf (both of you, one for reading, one for perhaps getting input for the article). :)  @lamitpObuS Yeah, the QR Code standard says that there's supposed to be a "quiet zone" around the code (which should be filled white). So that's probably what's happening there! If the quiet zone is not there, your reader doesn't recognize the code. @piko  An excellent and approachable write-up. I hope I never find myself in a situation where I need to actually decode one of these by hand, but it's interesting to understand how it works.   @confusomu @blinry @piko  This is quite handy but I also hope I never have to do it, lol. Thank you for sharing!  Cool! Related: the gist of this ad is, "The only safe QR code is our QR code." Seen @ Charlotte, NC, USA Airport @bitman @blinry @piko I'll start with that only if they have the 3 square alingnment boxes in the corners is it a QR code. Most of the data on said cards from what I can see from a google search is not in a QR Code format, but a variant of PDF417 (this is not the same PDF as the file format from adobe). Such a format is a bit more complex than QR Code with using a base 929 encoding of the data. @bitman @blinry @piko @blinry @piko very cool dynamic tutorial!   @blinry @piko There's a small animated GIF in this post, that quickly goes through the same info. @cybeardjm @blinry @piko p.s. while the @cybeardjm “content creation…” QR scans just fine on my iPhone’s scanner, the interactive decoder by @blinry and @piko running in iOS safari refuses to recognise it :( @lgvs @whybird @cybeardjm @blinry @piko I don't think it is mentioned on the page, but in the code: To minimize uniform-color areas and eye-like patterns. This is fabulously well done, thank you! ❤️ I had to slog through tons of materials to figure this out a few years' back for a dissertation-adjacent project* but never did manage to figure out masking manually, so ended up using a generator for the final pattern. *made a QR code of my dissertation research question in Miyuki seed beads. Still haven't finished as it takes a LONG time! 😀 @blinry @piko also, at least on iPhone if you take a screenshot that has a QR code in it the code becomes a clickable link in the photos app. Not sure if that’s true on android too. That’s why I’ve been slathering qrs in all my shorts and Insta posts. It’s a handy way to be like “I want to check that link out later”. Leave it to me to break it. ;) The page does well up to 42 ascii characters, but any more than that (checked up to 45) it lists the length as 37 and decodes the first two letters that it shows incorrectly. It's when it goes from version 3 to version 4. Thank you for this! You gave me a good start. Now I have to dig more deeply into it. @leuschner @blinry I don't think so. It was hold in a workshop room and we even moved to a different place. I haven't seen a camera. Also they did some practical training. But maybe on the next congress you can make a talk of it. I found it very interesting and as there where a lot of people interested at 37C3 as well, it's probably a good idea to have a recorded version. @marinheiro @blinry Yes, that's why there are actually two places for the mask pattern bits. And it still seems to work if both are covered! 🤨 (I tried it just now :D) I think there's still so much more to the error correction (which would be too much effort to do it completely in your head) that it somehow is really stable...  @blinry @piko Because I made a QR Code watchface for the Watchy (https://github.com/Cqoicebordel/Watchfaces/tree/main/QR_Watchface), and I guarantee trying to decode alphanum data on paper or in your head is hard, each char use 5½ bits. All that to say, it would have been funnier to use alphanumeric encoding ;) @blinry @piko Some time ago I learned about QR codes out of curiosity. However, you inspired me to use my pixel art editor to draw some QRs. The rainbow colored one can't be read by my reader, so a little more work needs to go into finding colors with enough contrast.  |
@blinry @piko FINALLY SOMEONE! Thanks!!!