3 ms·

No OP, but I'm aware of a few: - scandit: https://www.scandit.com/developers/ https://www.scandit.com/developers/ - cognex: https://cmbdn.cognex.com/ https://

No OP, but I'm aware of a few: - scandit: https://www.scandit.com/developers/ https://www.scandit.com/developers/ - cognex: https://cmbdn.cognex.com/ https://cmbdn.cognex.com/ - aspose: https://products.aspose.com/barcode/ https://products.aspose.com/barcode/ In open source, I heard of libdmtx[0], but not much happens on it these days. I also saw html5-qrcode[1] [0]: https://github.com/dmtx https://github.com/dmtx [1]: https://github.com/mebjas/html5-qrcode https://github.com/mebjas/html5-qrcode, which directly depends on a port of zxing to javascript.

cameldrv 5y ago
There are a lot more QR code libraries available, and while they're conceptually very similar, the open source DataMatrix libraries are much less developed and are far less reliable.
gregsadetsky 5y ago
Fascinating, thanks a lot for these. Scandit and Cognex have iOS apps, and Aspose has a web recognizer demo. I tried all three with a 2D QR code (my vax card!) from which I truncated ~2-3 bit-"rows" from the bottom. None of the apps/site detected the code. This is truly not a thorough test -- the 2D rows may be more information-dense than I think i.e. they are not recoverable using the built-in error correction (basically I'm removing too much information -- the equivalent of a long/deep scratch on a CD). -- I'm just trying to get an intuitive sense of how much damage a QR code can sustain and ... I guess if there's such a thing as QR code forensics (there must be...??) for decoding partial codes versus not detecting "anything". Thanks again for the links. Super interesting space
- jhugo 5y ago
  When generating a QR code, you can decide how much redundancy to include, making the QR larger for the same data but more resilient to "scratches".
  - gregsadetsky 5y ago
    Thanks. Looking into it [0], the QR code I'm testing uses the "up to 7% damage" error correction level L, which makes sense since there's already a lot of data being packed in the (vax proof) code. ... I still want to find a debugging/verbose QR decoder :-) [0] https://blog.qrstuff.com/2011/12/14/qr-code-error-correction https://blog.qrstuff.com/2011/12/14/qr-code-error-correction
amelius 5y ago
I tried libdmtx, but it was extremely slow, and also it had problems with most of my barcodes, even after I cleaned up the images as much as I could.

cameldrv 5y ago

There are a lot more QR code libraries available, and while they're conceptually very similar, the open source DataMatrix libraries are much less developed and are far less reliable.

gregsadetsky 5y ago

Fascinating, thanks a lot for these. Scandit and Cognex have iOS apps, and Aspose has a web recognizer demo. I tried all three with a 2D QR code (my vax card!) from which I truncated ~2-3 bit-"rows" from the bottom. None of the apps/site detected the code. This is truly not a thorough test -- the 2D rows may be more information-dense than I think i.e. they are not recoverable using the built-in error correction (basically I'm removing too much information -- the equivalent of a long/deep scratch on a CD). -- I'm just trying to get an intuitive sense of how much damage a QR code can sustain and ... I guess if there's such a thing as QR code forensics (there must be...??) for decoding partial codes versus not detecting "anything". Thanks again for the links. Super interesting space

jhugo 5y ago
When generating a QR code, you can decide how much redundancy to include, making the QR larger for the same data but more resilient to "scratches".
- gregsadetsky 5y ago
  Thanks. Looking into it [0], the QR code I'm testing uses the "up to 7% damage" error correction level L, which makes sense since there's already a lot of data being packed in the (vax proof) code. ... I still want to find a debugging/verbose QR decoder :-) [0] https://blog.qrstuff.com/2011/12/14/qr-code-error-correction https://blog.qrstuff.com/2011/12/14/qr-code-error-correction

amelius 5y ago

I tried libdmtx, but it was extremely slow, and also it had problems with most of my barcodes, even after I cleaned up the images as much as I could.