self.mpHands = mp.solutions.hands
self.hands = self.mpHands.Hands(static_image_mode=self.mode,
max_num_hands=self.maxHands,
min_detection_confidence=self.detectionCon,
min_tracking_confidence=self.trackCon)
self.mpDraw = mp.solutions.drawing_utils
self.hands.process(img) 即可得到预测结果results，输入图需要是RGB通道