Mastering OpenCV 4 with Python

Detecting markers

You can use the cv2.aruco.detectMarkers() function to detect the markers in an image:

corners, ids, rejected_corners = cv2.aruco.detectMarkers(gray_frame, aruco_dictionary, parameters=parameters)

The first parameter of cv2.aruco.detectMarkers() is the grayscale image where the markers are going to be detected. The second parameter is the dictionary object, which should have been previously created. The third parameter establishes all of the parameters that can be customized during the detection process. This function returns the following information:

• The list of corners of the detected markers is returned. For each marker, its four corners (top-left, top-right, bottom-right, and bottom-left) are returned.
• The list of the ...