Support inverted qr-codes

[ao2]

The app does not recognize inverted qr-codes: those with light foreground color on a dark background.

There is a discussion open about this in the zxing issue tracker, at zxing/zxing#194

Some apps solved the issue by processing the frame twice themselves, like dm77/barcodescanner#265 or freeotp/freeotp-android#192

But I think the library should provide this option itself.

Ciao,
Antonio

[Kamuno]

Thank you for pointing this out. However, we will not include this fix ourselfes. We will update to the newest zxing version is they choose to fix this.

[ao2]

Totally understandable, thanks for the reply.

[Kamuno]

If I understand is correctly this should be fixed. We will need to take a look again.

[Kamuno]

Fixed via 1144caa