Swiss QR-bills (ISO 20022) not working in some cases

[sbrunner]

System information (version)

• OpenCV => 4.6.0.66 and 4.4.0.46
• Operating System / Platform => Linux
• Compiler => Using the Python package with Python 3.10

Detailed description

The Swiss QR-bills are detected, but not always decoded.

See also:

• https://scanbot.io/en/sdk/scanner-sdk/barcode-scanner-sdk/swiss-qr
• Swiss QR-bills (ISO 20022) not decoded  #21929 (comment)

Steps to reproduce

Used image:

import cv2

image = cv2.imread("....png")
detector = cv2.QRCodeDetector()

data, bbox, straight_qrcode = detector.detectAndDecode(image)
print(data)
print(bbox)

In cases like this one, it steels not working...

I get the bbox:

[[ 21.436857  23.88773 ]
 [564.2752    25.00468 ]
 [559.34143  562.7794  ]
 [ 16.857067 559.7231  ]]

But no data...

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues,
  forum.opencv.org, Stack Overflow, etc and have not found any solution
• I updated to the latest OpenCV version and the issue is still there
• There is reproducer code and related data files: videos, images, onnx, etc

[AleksandrPanov]

QR codes of large versions are still not decoded well in OpenCV

[AleksandrPanov]

@sbrunner try to use wechat detector

[sbrunner]

Effectively, I get good result with him :-) Thanks

[crackwitz]

someone on Stack Overflow reports issues with those Swiss codes too: https://stackoverflow.com/questions/76362026/qr-code-detecting-in-python-with-opencv-raises-unicodedecodeerror-utf-8-codec

In that case, an UnicodeDecodeError is thrown. I don't see how that should ever happen. It's either binary data, or the encoding should have been specified by the standard or the code itself.