I have an example of a QR code which Quirc is not able do decode. It can locate it within the image but fails later with an ECC error when decoding the data. I checked the code with the Quirc inspect tool and the pixels appear to have been read correctly. I wonder if the problem is related to the small overlayed image in the center (it's required by the Swiss QR bill standard). Other QR code readers such as ZXing or the built-in QR code reader on iOS are able to decode the image correctly. boofcv on the other hand also fails to decode the QR code data.

The QR-code example image has been intentionally removed.