cross-posted from: https://lemmy.ml/post/33289366
obligatory I know this is not a linux question, but you provide good information and alternatives
qr code is the squares code that, if used with a qr code scanner redirects me automatically to a website or to download a pkpass file, right?
after downloading said pkpass file to my android, any wallet application like fosswallet should recognize it and add it to the local library (on my android device), right?
what other formats do transportation authorities use?
To those residing in Germany, is pkpass use widespread there? What are common formats used there?
They are not at all the same thing.
A QR code is just a 2D barcode that can be used to hold a certain amount of alphanumeric data (and amount is limited by size).
While pkpass is an Apple format used in its wallet app to store data.
Aren’t all barcodes 2D?
EDIT No wait, they’re basically 1D aren’t they? Nevermind!
Exactly. No matter the y dimension. Barcode data is only stored in x. Whereas QR uses x and y for data.
They also use the corner squares and a few specific dots to allow scanning from greater angles. Basically allowing the data to be read in 3d space. Even though only 2d is used to store that data.
This is why QR can work well with cameras. Whereas bar codes are designed for very short range laser reflection.
PS lots of info on QR online including open source programs to make your own.
The same goes for bar codes. But readers involve some very simple maker skills. Making simple barcode readers was a common school science project in the early 90s.
Your generic “barcode” for something like a UPC is considered a 1D barcode and uses things like the spacing of the lines and thickness to encode data. Although some 1D barcodes can detect the barcode is damaged they cannot do error recovery.
Your 2D barcodes, like QR or Data Matrix, store data in both directions and depending on format can have varying levels of error correction (duplicate data) built into the barcode. They also obviously can take up less room and hold the same or more data as well. You do need a scanner that can do 2D barcodes though, as not all scanners will read them.
