如何使用tkinter和opencv拍摄不会冻结的照片？

import tkinter as tk
import cv2
from PIL import Image, ImageTk

window = tk.Tk()
window.title("拍摄照片")

label = tk.Label(window)
label.pack()

def capture_image():
    ret, frame = cap.read()  # 从摄像头读取图像
    if ret:
        cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)  # 将图像从BGR转换为RGB格式
        image = Image.fromarray(cv2image)  # 将图像转换为PIL Image对象
        imgtk = ImageTk.PhotoImage(image=image)  # 创建PhotoImage对象
        label.imgtk = imgtk  # 保持对PhotoImage对象的引用，避免被垃圾回收
        label.configure(image=imgtk)  # 在标签上显示图像

capture_button = tk.Button(window, text="拍摄照片", command=capture_image)
capture_button.pack()

cap = cv2.VideoCapture(0)  # 打开摄像头，参数0表示默认摄像头

window.mainloop()

import tkinter as tk
import cv2
from PIL import Image, ImageTk

window = tk.Tk()
window.title("拍摄照片")

label = tk.Label(window)
label.pack()

def capture_image():
    ret, frame = cap.read()
    if ret:
        cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
        image = Image.fromarray(cv2image)
        imgtk = ImageTk.PhotoImage(image=image)
        label.imgtk = imgtk
        label.configure(image=imgtk)

capture_button = tk.Button(window, text="拍摄照片", command=capture_image)
capture_button.pack()

cap = cv2.VideoCapture(0)

window.mainloop()