ImageTk.PhotoImage resize code example
Example: how to rezize image in python tkinter
from tkinter import *
from PIL import ImageTk, Image
root=Tk()
image = Image.open('path_to_your_image.png')
# The (450, 350) is (height, width)
image = image.resize((450, 350), Image.ANTIALIAS)
my_img = ImageTk.PhotoImage(image)
my_img = Label(image = my_img)
my_img.pack()
root.mainloop()