Here’s my attempt, modified from another post, to create a minimal loop where I create a numpy array and display it. (For convenience I have a Start button.)
It works fine, with one exception — it runs at full speed, regardless of what delay I put in as the first argument to self.after (it’s 1000 in the example below. Changing this arg has no visible effect.)
What am I missing? (I am running python 3.8.3. Oh, that’s apparently a very old version. Damn. I’ll go update just in case that’s related to the issue.)
from PIL import ImageTk
import numpy as np
import tkinter as tk
class App(tk.Tk):
def __init__(self):
super().__init__()
self.canvas = tk.Canvas(self, width = 1200, height=1200)
self.canvas.pack()
tk.Button(self, text="Start", command=self.start_animation).pack()
def start_animation(self):
self.canvas.delete('all')
# generate a random test frame
im = np.random.randint(0, 255, (1024,1024,3), dtype="uint8")
im1 = Image.fromarray(im, 'RGB')
im2 = ImageTk.PhotoImage(im1)
self.canvas.create_image(600, 600, image=im2)
self.update()
self.after(1000, self.start_animation())
if __name__ == '__main__':
App().mainloop()
7
Some points here
- Value for option
commandfor atk.Buttonshould be a function, not the result of that function.
tk.Button(self, text="Start", command=self.start_animation)
- There should be a reference for your
ImageTk.PhotoImageobject, or it won’t shown on your canvas.
self.im2 = ImageTk.PhotoImage(im1)
Imagenot imported fromPillow.
Exaample Code
from PIL import Image, ImageTk
import numpy as np
import tkinter as tk
class App(tk.Tk):
def __init__(self):
super().__init__()
self.canvas = tk.Canvas(self, width = 200, height=200)
self.canvas.pack()
tk.Button(self, text="Start", command=self.start_animation).pack()
def start_animation(self):
self.canvas.delete('all')
# generate a random test frame
im = np.random.randint(0, 255, (200, 200, 3), dtype="uint8")
im1 = Image.fromarray(im, 'RGB')
self.im2 = ImageTk.PhotoImage(im1)
self.canvas.create_image(0, 0, image=self.im2, anchor=tk.NW)
self.update()
self.after(1000, self.start_animation)
if __name__ == '__main__':
App().mainloop()
1