Python Tkinter添加背景图后精灵移动卡顿问题求助

在Mac系统的PyCharm中使用Tkinter的Canvas组件，通过按键绑定实现精灵图像的屏幕移动。添加背景图后，移动速度大幅变慢且卡顿；移除背景图后，移动则流畅如预期。使用Tkinter已有数年，此问题为首次出现，移除背景图移动流畅，重新添加后又变得迟缓。

from tkinter import *

window = Tk()
# 创建画布
playground = Canvas(window, height=1500, width=1500, bg="green")
playground.pack()

# 移除这张背景图后，图像移动就流畅顺滑了
bgImg = PhotoImage(file="pacbg.png")
bg_Img = bgImg
bg = playground.create_image(0, 0, anchor = NW, image=bgImg)

# 通过按键绑定移动的图像
pmanImg = PhotoImage(file="pac.png")
pman_Img = pmanImg
pman = playground.create_image(100, 100, image=pmanImg)


# 向右移动图像
def fluidright(event):
    global rightLoop, leftLoop
    try:
        window.after_cancel(leftLoop)
        playground.move(pman, 10, 0)
        rightLoop = window.after(10, lambda: fluidright(event))
    except NameError:
        playground.move(pman, 10, 0)
        rightLoop = window.after(10, lambda: fluidright(event))


# 停止向右移动
def stopright(event):
    global rightLoop
    window.after_cancel(rightLoop)

# 向左移动图像
def fluidleft(event):
    global rightLoop, leftLoop
    try:
        window.after_cancel(rightLoop)
        playground.move(pman, -10, 0)
        leftLoop = window.after(10, lambda: fluidleft(event))
    except NameError:
        playground.move(pman, -10, 0)
        leftLoop = window.after(10, lambda: fluidleft(event))

# 停止向左移动
def stopleft(event):
    global leftLoop
    window.after_cancel(leftLoop)


# 按键绑定
playground.bind_all("<Right>", fluidright)
playground.bind_all("<Left>", fluidleft)
playground.bind_all("<KeyRelease - Right>", stopright)
playground.bind_all("<KeyRelease - Left>", stopleft)


window.mainloop()

内容的提问来源于stack exchange，提问作者Teach