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.
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?
QR codes are great for augmenting ads, booklets and other stuff, but if you want reliable readability, you shouldn't go with more than a simple color change, in my experience.
I was tasked with creating QR codes for certificates (every certificate leads to a unique page for the certificate number on the website, for security and more information since the certificates were small and made to be pretty instead of useful).
We ended up with Level M golden (more like dark yellow) colored QR codes in the corner - using higher error correction is actually detrimental the smaller you go, and backgrounds, embossing or any kind of advanced design would lead to it being very hard to read - it's better to have a plain ugly QR code that is immediately scannable with any device than a pretty one that is unreadable (just imagine your buyers trying to scan the damn thing five times in a row then give up in frustration).
But the client really liked the idea (and the results), and I am still surprised that so many people don't even consider this nowadays...
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[ 2.9 ms ] story [ 119 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.
I was tasked with creating QR codes for certificates (every certificate leads to a unique page for the certificate number on the website, for security and more information since the certificates were small and made to be pretty instead of useful).
We ended up with Level M golden (more like dark yellow) colored QR codes in the corner - using higher error correction is actually detrimental the smaller you go, and backgrounds, embossing or any kind of advanced design would lead to it being very hard to read - it's better to have a plain ugly QR code that is immediately scannable with any device than a pretty one that is unreadable (just imagine your buyers trying to scan the damn thing five times in a row then give up in frustration).
But the client really liked the idea (and the results), and I am still surprised that so many people don't even consider this nowadays...