Yes -- me too. Using RedLaser, I was able to scan 5 (low contrast), 9 (missing position square), 11 (vertical gap), 25 (warp drive), and 29 and 30 (ant invasion). I was not able to scan 17 (extreme tilt) or 23 (dizziness). This points out how important the software is.
"These are not the pixels you are looking for." Choice.
I did an experiment once where I took a sharpie and colored in "random" (to me) squares of a QR code. I managed to fill in quite a few before it stopped scanning (maybe 10-20).
The problem are the three big squares in the edges, if they are damaged the QR code won't be recognized as such - and the edges are usually what gets damaged first.
Yes, but assuming errors are uniformly distributed, there's a chance read errors will actually correct problems. They'll occasionally flip the bit that was tampered with.
So error correction gets worse (less effective), but maybe not as bad as you might believe.
It depends on how creative they get. If they're just rounding the corners on the squares to make it look more fluid, then it's definitely not a full 20% being used. If they're plopping a logo into the center of it, then it depends on how large the logo is proportional to the code's size.
The bit at the end made me happy - I didn't know QR codes code be that large. I wonder what the practical maximum number of bits is? I just tried the ones on the Wikipedia page (http://en.wikipedia.org/wiki/QR_code#Storage) - the one that's 5 alignment blocks wide scans, but the one that's 7 alignment blocks wide does not. I assume my primitive old phone's camera lacks the resolution for it. Unfortunately the captions are wrong - they both say 177x177.
There's a 3DS game called Pullblox (or Pushmo), which allows you to make your own (low-res 2D bitmap) levels and then distribute them via a massive QR-code.
I was actually wondering the same exact thing for one of my clients. We are using QR codes (and their scans) to enable distribution of music for independent (unsigned) bands, while tracking who their new fans are, and how they're getting new fans. The core is a marketing/analytics tool/engine, but the front-facing product to the fan is a simple fangate.
I have some QR code artwork hanging on a wall in my house. That artwork made it into a photo that happened to be taken in that room which I shared on Facebook. I was surprised when someone was able to take that photo, zoom in on the off-angle unevenly-lit code behind glass, scan it and post its message as a comment.
One thing that still bugs me about QR code error correction is the lack of support for codes with inverted color schemes. Unless I'm mistaken, this feature should be relatively simple to implement (ie. checking for two patterns) yet most of the applications I know fail at reading an inverted code (ie google goggles).
What purpose do inverted colors serve? Is there some use of QR codes that is poorly served by the standard scheme but better served by an inverted one?
51 comments
[ 3.7 ms ] story [ 120 ms ] threadhttp://research.swtch.com/qart
and this one has the benefit of allowing you to make a qr code with your face on it :)
http://cgv.cs.nthu.edu.tw/Projects/Recreational_Graphics/Hal...
http://140.114.79.59:99/halftoneQRC.aspx
I was able to scan at least two that the author said weren't scannable.
https://itunes.apple.com/ca/app/qrafter-qr-code-barcode-read...
Don't let the last one get you down.
"These are not the pixels you are looking for." Choice.
Are you by any chance a Kiwi?
One of the more creative ones I've seen recently is creating a really long-term data storage (Giga-Year) based on QR-Codes - http://vimeo.com/77028789
So error correction gets worse (less effective), but maybe not as bad as you might believe.
Without that, you have to awkwardly scan from exactly the correct direction.
The thing is, you surely could correct for that(?)
1. Spray painted code. Does it scan? (author says NO)
That being said, if you are putting QR codes on anything aesthetics are probably not something that even registers with you.