EddyVerbruggen/barcodescanner-lib-aar

Cannot Find some QR Codes

Closed this issue · 5 comments

herman1vdb commented

Problematic QR Code:
image

Finding (also changing the angle of the QR code to 45° scans successfully):
image

herman1vdb commented

After further investigation it seems the vertical and horizontal pattern is accepted at the incorrect center, for this particular QR Code.
Which lead me to come across these concerns:

It seems at FinderPatternFinder.java:78
pureBarcode = hints != null && hints.containsKey(DecodeHintType.PURE_BARCODE);
the default for pureBarcode is false (I'd rather assume most QR Codes are pure monochrome?)
eg. pureBarcode = hints == null || hints.containsKey(DecodeHintType.PURE_BARCODE);

In any case at FinderPatternFinder.java:496 it seems that the diagonal check is ignored when it is not monochrome (!pureBarcode || crossCheckDiagonal(...). This seems strange can someone please explain the reasoning behind this, I don't understand it. According to me it should still do the check regardless if it is a pureBarcode or not.

Unfortunately I'm currently unable to run any tests

meaning of Pure Barcode:

  /**
   * Image is a pure monochrome image of a barcode. Doesn't matter what it maps to;
   * use {@link Boolean#TRUE}.
   */
  PURE_BARCODE(Void.class),

DecodeHintType.java

EddyVerbruggen commented

Hi, I think you're best off asking this at the repo where this is actually maintained. The code you found in this repo is similar to the original: https://github.com/zxing/zxing/blob/master/core/src/main/java/com/google/zxing/qrcode/detector/FinderPatternFinder.java

Sorry that it's not too clear that this is 'soft fork'.

herman1vdb commented

Ok will do.
Further down the Rabbit hole I go :)

EddyVerbruggen commented

Haha, good luck! 👍

herman1vdb commented

@EddyVerbruggen can you please update with the fix zxing/zxing#906
Can you also updated the phonegap plugin again?