环境：
python3.8

描述：使用opencv读取摄像头帧数据，使用mediapipe检测手指坐标

个人学习记录不喜勿喷
贴上代码：

# 手势拖拽方块

import cv2
import numpy as np

# mediapipe 参数
import mediapipe as mp
mp_drawing = mp.solutions.drawing_utils
mp_drawing_styles = mp.solutions.drawing_styles
mp_hands = mp.solutions.hands

hands =  mp_hands.Hands(
   model_complexity=0,
   min_detection_confidence=0.5,
   min_tracking_confidence=0.5)


# 获取摄像头视频流
cap = cv2.VideoCapture(0)
# 获取画面宽度和高度
width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))
height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))

#  方块参数
square_x = 100
square_y = 100
square_width = 100

L1 = 0
L2 = 0
on_square = False

while True:
   # 读取视频帧数据
   ret,frame = cap.read()

   # 对图像进行处理
   # 镜像处理
   frame = cv2.flip(frame,1)

   # mediapip处理 
   frame.flags.writeable = False
   frame = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
   results = hands.process(frame)

     # Draw the hand annotations on the image.
   frame.flags.writeable = True
   frame = cv2.cvtColor(frame, cv2.COLOR_RGB2BGR)

   # 解析results
   # 判断是否出现双手
   if results.multi_hand_landmarks:
     #解析每一双手
     for hand_landmarks in results.multi_hand_landmarks:
       # 绘制21个关键点
       mp_drawing.draw_landmarks(
           frame,
           hand_landmarks,
           mp_hands.HAND_CONNECTIONS,
           mp_drawing_styles.get_default_hand_landmarks_style(),
           mp_drawing_styles.get_default_hand_connections_style())
       # print(hand_landmarks)
       x_list = []
       y_list = []
       for landmark in hand_landmarks.landmark:
          #添加x坐标
          x_list.append(landmark.x)
          #添加y坐标
          y_list.append(landmark.y)
       # 获取食指指尖x y坐标
       index_finger_x = int(x_list[8]*width)
       index_finger_y = int(y_list[8]*height)
       # 画一个圆验证坐标
       # cv2.circle(frame,(index_finger_x,index_finger_y),30,(255,0,255),-1)

       # 判断食指指尖在不在方块上
       if (index_finger_x > square_x) and (index_finger_x < (square_x + square_width)) and (index_finger_y > square_y) and (index_finger_y < (square_y + square_width)):
           L1 = abs(index_finger_x - square_x)
           L2 = abs(index_finger_y - square_y)
           on_square = True

       if on_square:
           square_x = index_finger_x - L1
           square_y = index_finger_y - L2
   else:
      on_square = False
   # 画一个方块
   cv2.rectangle(frame,(square_x,square_y),(square_x+square_width,square_y+square_width),(255,0,0),-1)

   # 显示
   cv2.imshow('virtual drag',frame)

   if cv2.waitKey(10)  & 0xFF == 27:
       break

cap.release()
cv2.destroyAllWindows()