【Python】Changing images periodically with tkinter
Overview
There is a good library in python to make GUI, that is tkinter. It can display images too. Here, we are trying to change images periodically with tkinter.
Python library to be used
Following three libraries are used.
- tkinter
‘tkinter’ is used to make GUI.
- PIL(pillow)
‘PIL’ is used to deal with images in the python.
- threading
‘threading’ is used to change images automatically. Detail about that will be explained later.
By the way, if you are using anaconda which contains these three libraries already , you don’t have to install them with pip command.
Step1 : Display a image with tkintertkinter
At first, we are defining a function to show a image with tkinter.
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | # import librariesimport sysimport tkinterfrom PIL import Image, ImageTkimport time# Definition of a function to display imagedef show_image():　　#Making instance of tkinter root = tkinter.Tk() root.title('test') root.geometry("400x300")　　# Opening image(Please change your actual path to your image) img = Image.open('yourimage.jpg') img = ImageTk.PhotoImage(img)　　# Definition of Canvas canvas = tkinter.Canvas(bg = "black", width=400, height=300) canvas.place(x=100, y=50) item = canvas.create_image(30, 30, image=img, anchor=tkinter.NW)　　# Display root.mainloop() |
This function displays image by using canvas method of tkinter. ImageTK is necessary to use jpg file.
Step2 : Changing images
The purpose of here is changing some images automatically with using the function before we defined. But that function seems to have the problem that only some objects on GUI can control tkinter when it’s executing root.mainloop. To change images periodically and automatically without GUI objects, we ‘re using threading library like following.
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 | import sysimport tkinterfrom PIL import Image, ImageTkimport threadingimport timedef show_image():　　 # Definition as global to be controlled out of the function global item, canvas root = tkinter.Tk() root.title('test') root.geometry("400x300") img = Image.open('your_image.jpg') img = ImageTk.PhotoImage(img) canvas = tkinter.Canvas(bg = "black", width=400, height=300) canvas.place(x=100, y=50) item = canvas.create_image(30, 30, image=img, anchor=tkinter.NW) root.mainloop()# make a thread and start to display a imagethread1 = threading.Thread(target=show_image)thread1.start()# Definition of a image to be changedimg2 = Image.open('your_image2.jpg')img2 = ImageTk.PhotoImage(img2)time.sleep(3) # cyclic 3 seconds#Rewrite the itemcanvas.itemconfig(item,image=img2)time.sleep(3)#Rewrite the item againimg = Image.open('your_image.jpg')img = ImageTk.PhotoImage(img)canvas.itemconfig(item,image=img) |
This code can display a first image in thread and change it to second one after 3 seconds.
Summary
It may not the best way but it can realize what we want to do by using threading and rewrite the item out of the function.
