Pan/Zoom Image class?

[Kurt]

Hi All,

I'm just getting started rewriting a small CAD/GIS like application
for designating outlines of objects in photographs/images in Python.
Is there a class out there that already handles panning and zooming
along with lines that have been drawn on top of the object? If got a
simple scrolling canvas working and user designation of objects with
the mouse. But I'm wondering if there is an elegant solution that
handles zooming too. I'm using Tkinter with a canvas, but at this
point I could switch to any GUI package. Any recommendations ?

Thanks!
-kurt

e.g. here is what i'm currently doing in a stripped down test program:

#!/usr/bin/env python
from Tkinter import *

class ScrolledCanvas( Frame):
def __init__(self, parent=None, color='white'):
Frame.__init__( self, parent)
self.pack(expan d=YES, fill=BOTH)
self.photo=Phot oImage (file="01pc.gif ")

canv=Canvas(sel f, bg=color, relief=SUNKEN)
canv.config(wid th=250, height=500)
canv.config(scr ollregion=(0,0, 300, 1000))
canv.create_ima ge(10,10, image=self.phot o, anchor=NW)

sbarY=Scrollbar (self)
sbarY.config(co mmand=canv.yvie w)
canv.config(ysc rollcommand=sba rY.set)
sbarY.pack(side =RIGHT, fill=Y)

sbarX=Scrollbar (self,orient='h orizontal')
sbarX.config(co mmand=canv.xvie w)
canv.config(xsc rollcommand=sba rX.set)
sbarX.pack(side =BOTTOM, fill=X)

canv.pack(side= LEFT, expand=YES, fill=BOTH)
Button(text="qu it", command=self.qu it).pack(fill=X )
if __name__ == '__main__':
ScrolledCanvas( ).mainloop()

[Diez B. Roggisch]

Hi,

I'm just getting started rewriting a small CAD/GIS like application
for designating outlines of objects in photographs/images in Python.
Is there a class out there that already handles panning and zooming
along with lines that have been drawn on top of the object?**If*got *a
simple scrolling canvas working and user designation of objects with
the mouse.**But*I'm *wondering*if*t here*is*an*eleg ant*solution*th at
handles zooming too.**I'm*using *Tkinter*with*a *canvas,*but*at *this
point I could switch to any GUI package.**Any*r ecommendations?

You could go for pygame and/or pyopengl. I'm not sure if there is a way to
embed a pygame-window or opengl window into a canvas, but maybe you can
roll out your own toolkit-implementation on top of pygame. (There is even
one, based on pygame and opengl, but it seems to work only under windows,
which I don't have)

Diez