zxing-js / ngx-scanner

Angular QR code, Barcode, DataMatrix, scanner component using ZXing.
https://zxing-js.github.io/ngx-scanner/
MIT License
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Found one Qr code not working but working well with the default system camera #451

Open PierreLucB opened 2 years ago

PierreLucB commented 2 years ago

I have a QR code not working. I can detect it with the native camera of my smartphone, but the library can't find it. I tried with the tryHarder = true, but it's not working.

All other QR codes (printed or numeric) I tested are detected very fastly !

The Qr code not working : image

lazmeister commented 2 years ago

I would think because the dots are not square but circles some readers may have issues on this one. This may just be related to the QR code itself. Whoever published/printed this barcode should look at QR code standards

jmelich commented 2 years ago

On the same lines, the same is happening to me with the attached QRcode, which is not made with dots. While is readable by other Qr readers(even from this library demo screenshotšŸ¤£) with no effort, could not be readed by this library. Can someone shed some light on?

Screenshot_20220127-234246

elmi82 commented 2 years ago

@PierreLucB @jmelich This library currently does not support scanning inverted QR codes AFAIK. See this issue https://github.com/zxing-js/ngx-scanner/issues/261

jmelich commented 2 years ago

Hey @elmi82 sorry for the delay and thanks for your reply.

It shed some light given I thought the detection mechanism was by color contrast between background and qr content. I'll try to invert the colors and check if it works.

Thanks once again.