Saving as Postscript

In the documentation there is no obvious save command for tkinter Canvas. The act of saving is performed by the command postscript(). File names the destination of the postscript string, otherwise we can use the output string. width determines how much of the X size of the canvas is to be printed, similarly height determines how much of the Y size is to be printed. The default is the visible width and/or height of the canvas. x and y are the leftmost and topmost canvas coordinates. colormode uses color for colour output, gray for greyscale and mono for black and white.

Image copied in IrfanView, original ps was 101 x 101, Ghostscript required

Show/Hide Code simple_save.py

from tkinter import Tk, Canvas
root = Tk()
canvas = Canvas(root)
canvas.pack()
rect = canvas.create_rectangle(10,10,100,100, fill="blue")
retval = canvas.postscript(file="../../images/canvas/saved.ps", height=100, width=100, colormode="color")
root.mainloop()

Few programs can view the ps file amongst which are Adobe Illustrator, Gimp or the quickest IrfanView - if converted to pdf then there are a lot more possibilities. Using a pdf viewer one can see that the file is saved as a very verbose vector file. Towards the end of the file saved.ps lie a few lines of vector code. Many printers still can use ps.

Depending on the computer setup, when viewing the text, one will see a line like 0.6 0.6 scale, with a high definition screen it may be 0.75 0.75 scale, on the graphic editors the size showed as 101 x 101 pixels - so scaling seemed to be ignored.