if __name__ == "__main__":
    root = Tk()
    panelA = None
    startFrame = Frame(root)
    mainFrame = Frame(root)
    bottomFrame = Frame(mainFrame)
    startFrame.pack()
    mainFrame.pack()
    bottomFrame.pack()
    createStartFrame()

    root.mainloop()

def createStartFrame():
    global panelA, startFrame
    startBtn = Button(startFrame, text="Start", command=partial(select_image))
    startBtn.pack()

    filename = "photo.jpg"
    print(filename)
    if len(filename) > 0:
        IMG = cv2.imread(filename)
    IMG = cv2.cvtColor(IMG, cv2.COLOR_RGB2GRAY)
    image = Image.fromarray(IMG)
    image = ImageTk.PhotoImage(image)
    if panelA is None:
        panelA = Label(startFrame, image=image)
        panelA.image = image
        panelA.pack(side="top", padx=10, pady=10)
    else:
        panelA.configure(image=image)
        panelA.image = image


def select_image():
    global panelA, gray, IMG, mainFrame, bottomFrame, root, startFrame
    startFrame.pack_forget()
    filename = "photo.jpg"
    print(filename)
    if len(filename) > 0:
        IMG = cv2.imread(filename)
    IMG = cv2.cvtColor(IMG, cv2.COLOR_BGR2RGB)
    noise_img = random_noise(IMG, mode='gaussian', var=0.1)
    noise_img = np.array(255 * noise_img, dtype='uint8')
    noise_img = cv2.cvtColor(noise_img, cv2.COLOR_RGB2GRAY)
    image = Image.fromarray(noise_img)
    image = ImageTk.PhotoImage(image)
    if panelA is None:
        panelA = Label(mainFrame, image=image)
        panelA.image = image
        panelA.pack(side="top", padx=10, pady=10)
        create_buttons(bottomFrame)
    else:
        panelA.configure(image=image)
        panelA.image = image