read fails (no error) if the background colour is darker

[Ultrabenosaurus]

I'm using the qrencode CLI package on my PC to play with QR codes and testing them on my Samsung Note 8 (Android 9, December security patch, not rooted) via this app and another QR reader from the Play Store. I typically prefer dark backgrounds in most things so I very quickly inverted the colours, specifically using this command:

qrencode -s 9 -v 3 -o wifi.png "WIFI:T:WPA;S:test;P:testestest;;" --foreground=cacbcd --background=262626

Here is the resulting QR code:

If I use the same command without specifying colours, or swap them so it's still greys but with the lighter shade being the background, then the app reads it instantly. The other app I'm testing with reads the inverted version just fine.

I've tried with other colours also and this app consistently fails to read QR codes where the background is darker than the dots.

I can see a closed issue #36 from 2018 where someone says "We will update to the newest zxing version is they choose to fix this." except shortly after that comment the referenced discussion thread on the zxing project went into maintenance and was no longer being actively developed with no intention to fix handling of inverted QR codes. If you are still using zxing then you might want to swap to a different system, though that is a separate issue. Inverted QR codes still need supporting in this app, regardless of implementation.

[Kamuno]

This should already be fixed in the current version. We added the capability to read inverted qr codes.