将绘图板输入保存为 JPEG

如何解决将绘图板输入保存为 JPEG

我创建了一个简单的画板：

from tkinter import *

canvas_width = 500
canvas_height = 150

def paint( event ):
   python_green = "#476042"
   x1,y1 = ( event.x - 1 ),( event.y - 1 )
   x2,y2 = ( event.x + 1 ),( event.y + 1 )
   w.create_oval( x1,y1,x2,y2,fill = python_green )

master = Tk()
master.title( "Painting using ovals" )
w = Canvas(master,width=canvas_width,height=canvas_height)
w.pack(expand = YES,fill = BOTH)
w.bind( "<B1-Motion>",paint )

message = Label( master,text = "Press and Drag the mouse to draw" )
message.pack( side = BottOM )
    
mainloop()

有没有办法将绘图保存并转换为白色背景的 JPG（也许通过添加按钮）？