WeChat QR code cannot detect and decode the QR code cropped from the image

[donalduk]

System information (version)

• OpenCV => 4.5.4
• Operating System / Platform => Ubuntu 21.10
• Compiler => GCC 11.2.0

Detailed description

I have built OpenCV 4.5.4 with WeChat QR code from the source code. Then I am trying to detect QR code with two sample QR codes. The 2dbarcode.jpeg is one QR code I downloaded from internet while the cropped-barcode.jpg is the QR code I cropped from one image. WeChat QR detector can detect and decode the QR code in 2dbarcode.jpeg. But it cannot detect the QR code in cropped-barcode.jpg. However If I use one QR Code app in my mobile to scan the cropped-barcode.jpg and the QR code mobile app can correctly detect and decode the QR Code in the cropped-barcode.jpg.

What should I need to do in order to detect and decode the cropped QR code from one image?

Steps to reproduce

import cv2 detector = cv2.wechat_qrcode_WeChatQRCode("./detect.prototxt", "./detect.caffemodel", "./sr.prototxt", "./sr.caffemodel") img=cv2.imread('./2dbarcode.jpeg') res, points = detector.detectAndDecode(img) print(res, points) img=cv2.imread('./cropped-barcode.jpg') res, points = detector.detectAndDecode(img) print(res, points)

Issue submission checklist

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

[ghost]

The code with the three bullseyes at the corners is a QR code. The other code (with the black L on the left and bottom) is a data matrix code. It is not readable by QR code readers.