4.2.3人脸检测服务实现章节

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为什么下面一直在等待？

源码
import rclpy
from rclpy.node import Node
from chapt4_interfaces.srv import FaceDetector
import face_recognition
import cv2
from ament_index_python.packages import get_package_share_directory #获取功能包share目录绝对路径
import os
from cv_bridge import CvBridge
import time

class FaceDetectNode(Node):
def init(self):
super().init('face_detect_node')
self.service_ = self.create_service(FaceDetector,'face_detect',self.detect_face_callback)
self.bridge = CvBridge()
self.number_of_times_to_upsample = 1
self.model = 'hog'
self.default_image_path = os.path.join(get_package_share_directory('demo_python_service') ,'resource/default.jpeg')
self.get_logger().info("人脸检测服务已经启动！")

def detect_face_callback(self, request, response):
    if request.image.data:
        cv_image = self.bridge.imgmsg_to_cv2(request.image)
    else:
        cv_image = cv2.imread(self.default_image_path)
        self.get_logger().info(f"传入图像为空，使用默认图像")
    #cv_image 已经是一个opencv格式的图像了
    start_time = time.time()
    self.get_logger().info(f"加载完成图像，开始识别")
    #检测人脸
    face_locations = face_recognition.face_locations(cv_image,
    number_of_times_to_upsample=self.number_of_times_to_upsample,model=self.model)
    response.use_time = time.time() - start_time
    response.number = len(face_locations)
    self.get_logger().info(f"识别完成，耗时：{response.use_time}!秒")
    for top,right,bottom,left in face_locations:
        response.top.append(top)
        response.right.append(right)
        response.bottom.append(bottom)
        response.left.append(left)
    return response         #返回【reponse

def main():
rclpy.init()
node = FaceDetectNode()
rclpy.spin(node)
rclpy.shutdown()