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.
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.
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.
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?
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 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.
Does anyone have a sense of what percentage of the smartphone-owning population actually knows what QR codes are and would bother to scan them? I'm as technically savvy as your average HN reader I would think, and I ignored the things for years before finally spending the 2 minutes to learn what they are. It's always made me assume that the average person wouldn't bother with them.
I would imagine this might be a tad optimistic, mainly due to their use being limited to only a few forms of advertisement (print being the main one). The only time I can remember using a QR code was when I watched a stream of the Google I/O 2010 conference and they showed one to get a CR-48 chromebook. Needless to say, that QR code will forever be my favorite 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...
Cool! I hand painted a QR code[0] in about .75x.75" onto a painting my father did for a friend and while working on it I spent about an hour or two implementing different codes of varying complexity in pencil to see how far I could go before it would get corrupted. It actually works[1] but it's on the wall in a music venue so unfortunately it takes a few extra seconds for some people's phones to adjust to the lower light.
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.
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 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).
