Issue in contourArea(src_points) in OpenCV QR-code detection

Python
1

I am on a project that detects the qrcode and its color. I encountered a problem that it randomly popped up an error message. I cannot figure why it would happen, I searched on the internet and I cannot find the answer. In fact, there are no topics about this error!

When there is no QR-code in the webcam, contourArea(src_points) gives the output 0.0 normally I believe. Somehow it will output 0 and I still cannot figure out why.

However , I stuck at a point where I cannot edit cv2.pyd to change from contourArea(src_points) > 0.0 to contourArea(src_points) > 0.0 or contourArea(src_points) > 0 .

Code below:

cap = cv2.VideoCapture(0)

lower_red = np.array([3, 60, 60])
upper_red = np.array([5, 255, 255])

while True:
    _, img = cap.read()
    img_hsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV)
    height, width, _ = img.shape
    cx = int(width / 2)
    cy = int(height / 2)  

    detector = cv2.QRCodeDetector()
    data, bbox, _ = detector.detectAndDecode(img)
    
    if(data and bbox is not None):
        print(data)
        print(np.int32(bbox))
        index_point = np.int32(bbox)

        rect = four_point_transform(img, index_point.reshape(4, 2))

        mask = cv2.inRange(img_hsv, lower_red, upper_red)
        mask_contours, hierarchy = cv2.findContours(mask, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE)

        if len(mask_contours) != 0:
            for mask_contour in mask_contours:
                if cv2.contourArea(mask_contour) > 200:
                        cv2.putText(img, "STOP", (cx + 200, cy + 230), 0, 1, (255, 255, 255), 4)
                        x, y, w, h = cv2.boundingRect(mask_contour)
                        cv2.rectangle(img, (x, y), (x + w, y + h), (0, 0, 255), 3) # Drawing rectangle

Error message:

Traceback (most recent call last):
  File "c:\Users\CSKPHC\Desktop\testing.py", line 58, in <module>
    data, bbox, _ = detector.detectAndDecode(img)
cv2.error: OpenCV(4.6.0) D:\a\opencv-python\opencv-python\opencv\modules\objdetect\src\qrcode.cpp:2489: error: (-2:Unspecified error) in function 'class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > __cdecl cv::QRCodeDetector::decode(const class cv::_InputArray &,const class cv::_InputArray &,const class cv::_OutputArray &)'
> Invalid QR code source points (expected: 'contourArea(src_points) > 0.0'), where
>     'contourArea(src_points)' is 0
> must be greater than
>     '0.0' is 0
2

crosspost: