Member Avatar for Lapinbriac

Hello,

I would like to save the drawings I have made on a Canvas with the Tkinter Module.

Is it possible to make a .jpg or .gif or .bmp from a Tkinter window ?

Thank you!

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  • Latest Post Latest Post by vegaseat

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A concise summary and practical options, building on ’s discovery of Canvas.postscript and ImageGrab and ’s suggestion to use an image viewer/screenshot tool.

The two reliable approaches are (A) export the canvas as PostScript and convert that to a bitmap, or (B) render into a Pillow image as you draw so you can save directly. PostScript conversion is simple and platform‑independent, but it requires a PostScript rasterizer (Ghostscript or ImageMagick) for conversion and it will not include Tkinter PhotoImage objects. Before calling postscript, make sure the canvas is fully laid out (call canvas.update() or canvas.update_idletasks()).

Example: save PostScript then open with Pillow (Ghostscript needed to read PS/EPS):

canvas.postscript(file='canvas.ps', colormode='color',
                  width=canvas.winfo_width(),
                  height=canvas.winfo_height())

from PIL import Image
img = Image.open('canvas.ps')   # requires Ghostscript available to Pillow
img = img.convert('RGB')
img.save('canvas.jpg', 'JPEG', quality=90)

If you need exact pixel-level control or you use embedded images on the canvas, mirror drawing commands into a Pillow ImageDraw object while you draw on the Tk canvas. That guarantees identical output and avoids external converters:

from PIL import Image, ImageDraw
w, h = canvas.winfo_width(), canvas.winfo_height()
img = Image.new('RGB', (w, h), 'white')
draw = ImageDraw.Draw(img)

# when drawing:
canvas.create_line(x1,y1,x2,y2, fill='black', width=2)
draw.line((x1,y1,x2,y2), fill='black', width=2)

img.save('export.jpg', 'JPEG', quality=90)

Troubleshooting notes: PostScript exports use 72 DPI by default (sizes may need scaling), fonts in PS may differ from screen fonts, and PhotoImage content won’t appear in PS — use the mirroring approach to include raster images. On Windows the ImageGrab approach mentioned earlier is the quickest throwaway method; for cross‑platform or repeatable results, prefer postscript+conversion or direct Pillow rendering.

Member Avatar for Lapinbriac

Ok i've found the response on www.developpez.net
It uses the .postscript method from canvas and the ImageGrab module

Bonjour,
Il y a la méthode '.postscript', qui génère ... du postscript.
Sous MS windows, tu peux utiliser ImageGrab (PIL). Je ne crois pas que cela fonctionne sous Linux.
x = canvas.winfo_rootx()
y = canvas.winfo_rooty()
w = canvas.winfo_width()
h = canvas.winfo_height()
img= ImageGrab.grab((x+2, y+2, x+w-2, y+h-2)).save("tmp.bmp")

Member Avatar for vegaseat

It would be simple to use the capture option that comes with many image viewers like XnView (nice and free).

For another potential solution look at:
http://www.daniweb.com/code/snippet705.html

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