Flask with opencv-python:在访问@app.route之前保持摄像头处于运行状态，并在发送GET请求时拍摄图像

pip install flask opencv-python

from flask import Flask, request, Response
import cv2

app = Flask(__name__)

@app.route('/')
def capture_image():
    # 打开摄像头
    cap = cv2.VideoCapture(0)
    
    # 检查摄像头是否成功打开
    if not cap.isOpened():
        return "无法打开摄像头"
    
    # 读取摄像头的图像
    ret, frame = cap.read()
    
    # 关闭摄像头
    cap.release()
    
    # 将图像转换为JPEG格式
    ret, jpeg = cv2.imencode('.jpg', frame)
    
    # 将图像数据作为响应返回
    return Response(jpeg.tobytes(), mimetype='image/jpeg')

if __name__ == '__main__':
    app.run()