How to update the image of a Tkinter Label widget?

Question:

I would like to be able to swap out an image on a Tkinter label, but I’m not sure how to do it, except for replacing the widget itself.

Currently, I can display an image like so:

import Tkinter as tk
import ImageTk

root = tk.Tk()
img = ImageTk.PhotoImage(Image.open(path))
panel = tk.Label(root, image = img)
panel.pack(side = "bottom", fill = "both", expand = "yes")
root.mainloop()

However, when the user hits, say the ENTER key, I’d like to change the image.

import Tkinter as tk
import ImageTk

root = tk.Tk()

img = ImageTk.PhotoImage(Image.open(path))
panel = tk.Label(root, image = img)
panel.pack(side = "bottom", fill = "both", expand = "yes")

def callback(e):
    # change image

root.bind("<Return>", callback)
root.mainloop()

Is this possible?

Asked By: skeggse

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Answers:

The method label.configure does work in panel.configure(image=img).

What I forgot to do was include the panel.image=img, to prevent garbage collection from deleting the image.

The following is the new version:

import Tkinter as tk
import ImageTk


root = tk.Tk()

img = ImageTk.PhotoImage(Image.open(path))
panel = tk.Label(root, image=img)
panel.pack(side="bottom", fill="both", expand="yes")

def callback(e):
    img2 = ImageTk.PhotoImage(Image.open(path2))
    panel.configure(image=img2)
    panel.image = img2

root.bind("<Return>", callback)
root.mainloop()

The original code works because the image is stored in the global variable img.

Answered By: skeggse

Another option to do it.

Using object-oriented programming and with an interactive interface to update the image.

from Tkinter import *
import tkFileDialog
from tkFileDialog import askdirectory
from PIL import  Image

class GUI(Frame):

    def __init__(self, master=None):
        Frame.__init__(self, master)
        w,h = 650, 650
        master.minsize(width=w, height=h)
        master.maxsize(width=w, height=h)
        self.pack()

        self.file = Button(self, text='Browse', command=self.choose)
        self.choose = Label(self, text="Choose file").pack()
        self.image = PhotoImage(file='cualitativa.gif')
        self.label = Label(image=self.image)


        self.file.pack()
        self.label.pack()

    def choose(self):
        ifile = tkFileDialog.askopenfile(parent=self,mode='rb',title='Choose a file')
        path = ifile.name
        self.image2 = PhotoImage(file=path)
        self.label.configure(image=self.image2)
        self.label.image=self.image2


root = Tk()
app = GUI(master=root)
app.mainloop()
root.destroy()

Replace ‘cualitativa.jpg’ for the default image you want to use.

Answered By: Daniel Santos

Another solution that might be of help.

In my case, I had two tk.Tk() windows. When using ImageTk.PhotoImage(), the object defaults to setting its tk window to being the first one created. A simple fix to this is to pass the tk window that you want as such ImageTk.PhotoImage(img, master=your_window)

import tkinter as tk 
from PIL import ImageTk, Image
if __name__ == '__main__':
     main_window = tk.Tk()
     second_window = tk.Tk()
     
     main_canvas = Canvas(second_window)
     main_canvas.pack()
     
     filename = 'test.png'

     img = Image.open(filename)
     img = img.resize((300, 100), Image.ANTIALIAS)
     logo = ImageTk.PhotoImage(img, master=second_window)
     logo_label = Label(master=main_canvas, image=logo)
     logo_label.image = logo
     logo_label.pack()

     main_window.mainloop()
Answered By: Mateo Conde