pip install mediapipe

import mediapipe as mp
import cv2
import numpy as np

if __name__ == "__main__":

    # 构建脸部特征提取对象
    mp_face_mesh = mp.solutions.face_mesh

    face_mesh = mp_face_mesh.FaceMesh(static_image_mode=False,
                                      max_num_faces=1,
                                      refine_landmarks=True,
                                      min_detection_confidence=0.5,
                                      min_tracking_confidence=0.5)
    # 构建绘图对象
    mp_drawing = mp.solutions.drawing_utils
    mp_drawing_styles = mp.solutions.drawing_styles

    # 开启摄像头
    cap = cv2.VideoCapture(0)

    while True:
        # 读取一帧图像
        success, img = cap.read()
        if not success:
            continue

        # 获取宽度和高低
        image_height, image_width, _ = np.shape(img)

        # BGR 转 RGB
        img_RGB = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)

        # 进行特征点提取
        results = face_mesh.process(img_RGB)

        if results.multi_face_landmarks:

            for face_landmarks in results.multi_face_landmarks:

                # 利用 内置的mp_drawing 进行绘图
                # mp_drawing.draw_landmarks(image=img,
                # landmark_list=face_landmarks,
                # connections=mp_face_mesh.FACEMESH_TESSELATION,
                # landmark_drawing_spec=None,
                # connection_drawing_spec=mp_drawing_styles
                # .get_default_face_mesh_tesselation_style())
                # mp_drawing.draw_landmarks(image=img,
                # landmark_list=face_landmarks,
                # connections=mp_face_mesh.FACEMESH_CONTOURS,
                # landmark_drawing_spec=None,
                # connection_drawing_spec=mp_drawing_styles
                # .get_default_face_mesh_contours_style())
                # mp_drawing.draw_landmarks(
                # image=img,
                # landmark_list=face_landmarks,
                # connections=mp_face_mesh.FACEMESH_IRISES,
                # landmark_drawing_spec=None,
                # connection_drawing_spec=mp_drawing_styles
                # .get_default_face_mesh_iris_connections_style())

                # 自行计算478个关键点的坐标 并绘制
                if face_landmarks:
                    # 计算关键点坐标
                    for i in range(478):
                        pos_x = int(face_landmarks.landmark[i].x * image_width)
                        pos_y = int(face_landmarks.landmark[i].y * image_height)

                        cv2.circle(img, (pos_x, pos_y), 3, (0, 255, 0), -1)

        cv2.imshow("face-mesh", img)

        key = cv2.waitKey(1) & 0xFF

        # 按键 "q" 退出
        if key == ord('q'):
            break
    cap.release()