Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Crowd Sourcing Broken QR Codes

humanqr.com

Post reply on HN
Print view View original

31–40 of 57 posts

Re: Crowd Sourcing Broken QR Codes

#31

Post by devmandan »

OtherShrezzing wrote: post #26

Reading the QR code spec (or even just the wikipedia page) could help a lot here. A lot of the room on the code is taken up by metadata, rather than output-data. The output data is repeated lots of times across the code (this is why you can have a brand logo right in the middle of the code). Repairing the metadata parts & iterating over each of the version number should make the overwhelming majority of broken QR cod…

I'm less interested in the theory and am more interested in the practice. I own a printed copy of the 2015 version of the spec, but don't find the insights I get from it have much to do with its ability to scan as compared to taking my phone out and scanning a QR code does.

In practice, I mostly I find that the corners are the most finicky part. However, that is just my current opinion.

Re: Crowd Sourcing Broken QR Codes

#32

Post by devmandan »

impune wrote: post #3

There is a tool called qrazy box https://merri.cx/qrazybox/ It allows you to essentially remake a damaged or partially hidden QR code pixel by pixel, but has some limitations.

This is exactly a baby-step in the right direction.

Basically, we put data into QR codes the same as hard drives. Why then are there so few data recovery tools for QR codes?

Re: Crowd Sourcing Broken QR Codes

#35

Post by jagged-chisel »

devmandan wrote: post #32
impune wrote: post #3

There is a tool called qrazy box https://merri.cx/qrazybox/ It allows you to essentially remake a damaged or partially hidden QR code pixel by pixel, but has some limitations.

This is exactly a baby-step in the right direction. Basically, we put data into QR codes the same as hard drives. Why then are there so few data recovery tools for QR codes?

But we don’t put terabytes, gigabytes, megabytes, or even kilobytes in QR codes. They don’t need to be recoverable in the same sense.

Re: Crowd Sourcing Broken QR Codes

#36

Post by dvdkon »

AStonesThrow wrote: post #25
wiradikusuma wrote: post #12

Earlier quoted context omitted.

Sometimes, because the service sneakily shortens the link. I wanted to share a WIP whitelabel ticket sales platform ( https://pentas.id ) with a friend. I didn't have time to build the logic to generate QR code, so I just googled "online QR generator". I pasted my link, a QR code was generated. When I tried it using Pixel's Camera app, the preview is NOT my link. Although when I tap it, it eventually goes to my link.

> I didn't have [money], so I just [had someone else pay to generate a QR]. Fixed that for you. If you are using free stuff that you google-searched, then you're the product.

A paid service/app would surely never pull such a trick, right?

It sadly requires a lot of vigilance not to fall for these "petty deceptions".

Re: Crowd Sourcing Broken QR Codes

#37

Post by simpaticoder »

devmandan wrote: post #2

A software tool should exist to repair QR codes. People could really benefit from it because QR codes are used everywhere. I'd like to find a way to repair QR codes through software. However, that begins with collecting a bunch of broken and corrupted QR codes people stumble across and fixing them up by hand. This will help spot patterns in how they fail. So please help out by submitting your QR code that doesn't sca…

I imagine that a really useful piece of information is where the QR code was spotted. So that means treating the photo of the QR code and its exif data as part of the puzzle. No doubt some URLs are more common in some parts of the world than others in a kind of ode to geoguessing games.

Re: Crowd Sourcing Broken QR Codes

#38

Post by devmandan »

wiradikusuma wrote: post #12
darkwater wrote: post #11

Earlier quoted context omitted.

This infuriates me. You are using a QR exactly to easily share a (long) link, why the hell you need to use a link shortener? Why is the market for small shops, restaurants, bars, small museums, small towns etc so riddled with technically incompetent people?

Sometimes, because the service sneakily shortens the link. I wanted to share a WIP whitelabel ticket sales platform ( https://pentas.id ) with a friend. I didn't have time to build the logic to generate QR code, so I just googled "online QR generator". I pasted my link, a QR code was generated. When I tried it using Pixel's Camera app, the preview is NOT my link. Although when I tap it, it eventually goes to my link.

Yup. Dark patterns exist with QR code hosting services. It's revolting.

Re: Crowd Sourcing Broken QR Codes

#39

Post by devmandan »

jagged-chisel wrote: post #35
devmandan wrote: post #32

Earlier quoted context omitted.

This is exactly a baby-step in the right direction. Basically, we put data into QR codes the same as hard drives. Why then are there so few data recovery tools for QR codes?

But we don’t put terabytes, gigabytes, megabytes, or even kilobytes in QR codes. They don’t need to be recoverable in the same sense.

Depends on the situation. It also depends on how sentimental a person is for their data or information needed in a given situation.

If a cat shows up on your doorstep and now you got to figure out who owns the cat because you become concerned about it over time, what do you do if you can't scan the QR code on its collar?

Re: Crowd Sourcing Broken QR Codes

#40

Post by MyPasswordSucks »

OtherShrezzing wrote: post #26

Reading the QR code spec (or even just the wikipedia page) could help a lot here. A lot of the room on the code is taken up by metadata, rather than output-data. The output data is repeated lots of times across the code (this is why you can have a brand logo right in the middle of the code). Repairing the metadata parts & iterating over each of the version number should make the overwhelming majority of broken QR cod…

> Reading the QR code spec (or even just the wikipedia page) could help a lot here.

Comprehending what you read could help a lot, too.

The output data generally isn't repeated even a single time in full, let alone "lots of times". That's what error correction keys are for.

The fact that you can stick a logo in the middle doesn't have much to do with anything. I can (and many publishers have!) put a bunch of color pictures in the middle of a book, it doesn't mean the data in the book is repeated.

Post reply on HN