function to take the corners from cv2.GoodFeaturesToTrack and return cv2.KeyPoints

def corners_to_keypoints(corners):
    """function to take the corners from cv2.GoodFeaturesToTrack and return cv2.KeyPoints"""
    if corners is None:
        keypoints = []
    else:
        keypoints = [cv2.KeyPoint(kp[0][0], kp[0][1], 1) for kp in corners]

    return keypoints