如何在Tkinter中将刚捕获的图片显示到指定Label组件中？

我正在开发一个项目，需要点击Capture按钮后，将刚捕获的图片显示到名为captureLabel的Label组件中，界面截图如下：

以下是我的完整main.py代码：

import tkinter as tk
import tkinter.font as tkFont
import cv2
from PIL import ImageTk, Image
import os
import time
import uuid

#setting title
gui = tk.Tk(className='yolov5')

#setting window size
width=1024
height=768
screenwidth = gui.winfo_screenwidth()
screenheight = gui.winfo_screenheight()
alignstr = '%dx%d+%d+%d' % (width, height, (screenwidth - width) / 2, (screenheight - height) / 2)
gui.geometry(alignstr)
gui.resizable(width=False, height=False)

cap = cv2.VideoCapture(0)
IMAGES_PATH_CAPTURED = os.path.join('Captured')
label = 'image'

#functions
def captureButton_command():
    textLabel['text'] = "Capture button clicked.."
    ret, frame = cap.read()
    imgname = os.path.join(IMAGES_PATH_CAPTURED, label+'.'+str(uuid.uuid1())+'.jpg')
    cv2.imwrite(imgname, frame)
    time.sleep(1)
    print("Image saved to {}".format(IMAGES_PATH_CAPTURED))
    
def exitButton_command():
    gui.destroy()
    
def video_stream():
    _, frame = cap.read()
    cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)
    img = Image.fromarray(cv2image)
    imgtk = ImageTk.PhotoImage(image=img)
    cameraLabel.imgtk = imgtk
    cameraLabel.configure(image=imgtk)
    cameraLabel.after(1, video_stream) 

#Capture Button
captureButton=tk.Button(gui)
captureButton["bg"] = "#efefef"
ft = tkFont.Font(family='Times',size=15)
captureButton["font"] = ft
captureButton["fg"] = "#000000"
captureButton["justify"] = "center"
captureButton["text"] = "Capture"
captureButton.place(x=10,y=220,width=150,height=50)
captureButton["command"] = captureButton_command

#Exit Button
exitButton=tk.Button(gui)
exitButton["bg"] = "#efefef"
ft = tkFont.Font(family='Times',size=15)
exitButton["font"] = ft
exitButton["fg"] = "#000000"
exitButton["justify"] = "center"
exitButton["text"] = "Exit"
exitButton.place(x=170,y=220,width=150,height=50)
exitButton["command"] = exitButton_command

#Message on top
textLabel=tk.Label(gui)
ft = tkFont.Font(family='Times',size=18)
textLabel["font"] = ft
textLabel["fg"] = "#333333"
textLabel["justify"] = "left"
textLabel["relief"] = "sunken"
textLabel["text"] = "Press capture to capture image"
textLabel.place(x=20,y=10,width=800,height=95)

#Camera Feed Label
cameraLabel=tk.Label(gui)
cameraLabel["text"] = "Camera Feed"
cameraLabel["borderwidth"] = "2px"
cameraLabel["relief"] = "solid"
cameraLabel.place(x=10,y=280,width=640,height=480)

#Captured Images Label
captureLabel = tk.Label(gui)
captureLabel["borderwidth"] = "2px"
captureLabel["relief"] = "solid"
captureLabel.place(x=720,y=110,width=300,height=300)

#Detected Images Label
detectedLabel = tk.Label(gui)
detectedLabel["borderwidth"] = "2px"
detectedLabel["relief"] = "solid"
detectedLabel.place(x=720,y=440,width=300,height=300)


            
#end
video_stream()
gui.mainloop()

我曾尝试先将图片保存到文件夹再读取显示，但该方法仅能显示程序启动前已保存的图片，无法显示刚捕获的最新图片。我期望在指定的带边框Label中显示一张图片，且每次点击捕获按钮后能替换显示最新的捕获图片。

解决方法 #

修改captureButton_command函数，直接使用捕获到的帧转换格式后更新captureLabel，同时保留图片对象引用避免被回收，还要移除阻塞界面的time.sleep(1)：

def captureButton_command():
    textLabel['text'] = "Capture button clicked.."
    ret, frame = cap.read()
    # 保存图片（如果不需要保存可删除以下两行）
    imgname = os.path.join(IMAGES_PATH_CAPTURED, label+'.'+str(uuid.uuid1())+'.jpg')
    cv2.imwrite(imgname, frame)
    
    # 转换帧格式为Tkinter支持的RGBA
    cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)
    img = Image.fromarray(cv2image)
    # 调整图片尺寸适配captureLabel的300x300大小
    img = img.resize((300, 300), Image.Resampling.LANCZOS)
    imgtk = ImageTk.PhotoImage(image=img)
    
    # 更新captureLabel并保留引用防止图片被回收
    captureLabel.imgtk = imgtk
    captureLabel.configure(image=imgtk)
    
    print("Image saved to {}".format(IMAGES_PATH_CAPTURED))

这样修改后，每次点击Capture按钮，最新捕获的图片就会立刻显示在captureLabel中，并且每次点击都会替换为新图片。

内容的提问来源于stack exchange，提问作者Ariel Arevalo