Tkinter Canvas Zoom + Move / Pan
Le widget Canvas de Tkinter a des fonctionnalités intégrées pour:
déplacer/déplacer le canevas (par exemple avec Click + Drag) avec
canvas.scan_marketcanvas.scan_dragto, voir cette questionzoomer les éléments vectoriels sur la toile avec
canvas.scale, mais malheureusement, cela ne fonctionne pas pour les images bitmap sur le canevas
Heureusement, cette méthode permet de zoomer sur les images (en redessinant manuellement la partie zoomée de l'image). Mais:
Comme nous redessinons une partie particulière du canevas, la fonction de déplacement/panoramique ne fonctionnera plus ...
Nous devons absolument rendre plus que la zone actuellement affichée, pour permettre le déplacement/panoramique. Disons que nous avons un bitmap 1000x1000 sur le canevas, et nous voulons zoomer d'un facteur 50x ... Comment éviter d'avoir un bitmap 50.000 x 50.000 pixels en mémoire? (2,5 gigapixels en RAM est trop grande). Nous pourrions penser à rendre la fenêtre uniquement, ou un peu plus que la fenêtre actuelle pour autoriser le panoramique, mais que faire une fois que le panoramique conduit à Bord de la zone rendue?
Comment avoir une fonction de déplacement/panoramique + zoom sur le canevas Tkinter, qui fonctionne pour les images?
Exemple de zoom avancé. Comme dans Google Maps.
Exemple de vidéo ( vidéo plus longue ici ):
Il zoome seulement une tuile, mais pas l'image entière. Ainsi, la tuile zoomée occupe une mémoire constante et ne la fourre pas avec une énorme image redimensionnée pour les gros zooms. Pour l'exemple de zoom simplifié regardez ici .
Testé sur Windows 7 64 bits et Python 3.6.2.
N'oubliez pas de placer un chemin vers votre image à la fin du script.
# -*- coding: utf-8 -*-
# Advanced zoom example. Like in Google Maps.
# It zooms only a tile, but not the whole image. So the zoomed tile occupies
# constant memory and not crams it with a huge resized image for the large zooms.
import random
import tkinter as tk
from tkinter import ttk
from PIL import Image, ImageTk
class AutoScrollbar(ttk.Scrollbar):
''' A scrollbar that hides itself if it's not needed.
Works only if you use the grid geometry manager '''
def set(self, lo, hi):
if float(lo) <= 0.0 and float(hi) >= 1.0:
self.grid_remove()
else:
self.grid()
ttk.Scrollbar.set(self, lo, hi)
def pack(self, **kw):
raise tk.TclError('Cannot use pack with this widget')
def place(self, **kw):
raise tk.TclError('Cannot use place with this widget')
class Zoom_Advanced(ttk.Frame):
''' Advanced zoom of the image '''
def __init__(self, mainframe, path):
''' Initialize the main Frame '''
ttk.Frame.__init__(self, master=mainframe)
self.master.title('Zoom with mouse wheel')
# Vertical and horizontal scrollbars for canvas
vbar = AutoScrollbar(self.master, orient='vertical')
hbar = AutoScrollbar(self.master, orient='horizontal')
vbar.grid(row=0, column=1, sticky='ns')
hbar.grid(row=1, column=0, sticky='we')
# Create canvas and put image on it
self.canvas = tk.Canvas(self.master, highlightthickness=0,
xscrollcommand=hbar.set, yscrollcommand=vbar.set)
self.canvas.grid(row=0, column=0, sticky='nswe')
self.canvas.update() # wait till canvas is created
vbar.configure(command=self.scroll_y) # bind scrollbars to the canvas
hbar.configure(command=self.scroll_x)
# Make the canvas expandable
self.master.rowconfigure(0, weight=1)
self.master.columnconfigure(0, weight=1)
# Bind events to the Canvas
self.canvas.bind('<Configure>', self.show_image) # canvas is resized
self.canvas.bind('<ButtonPress-1>', self.move_from)
self.canvas.bind('<B1-Motion>', self.move_to)
self.canvas.bind('<MouseWheel>', self.wheel) # with Windows and MacOS, but not Linux
self.canvas.bind('<Button-5>', self.wheel) # only with Linux, wheel scroll down
self.canvas.bind('<Button-4>', self.wheel) # only with Linux, wheel scroll up
self.image = Image.open(path) # open image
self.width, self.height = self.image.size
self.imscale = 1.0 # scale for the canvaas image
self.delta = 1.3 # zoom magnitude
# Put image into container rectangle and use it to set proper coordinates to the image
self.container = self.canvas.create_rectangle(0, 0, self.width, self.height, width=0)
# Plot some optional random rectangles for the test purposes
minsize, maxsize, number = 5, 20, 10
for n in range(number):
x0 = random.randint(0, self.width - maxsize)
y0 = random.randint(0, self.height - maxsize)
x1 = x0 + random.randint(minsize, maxsize)
y1 = y0 + random.randint(minsize, maxsize)
color = ('red', 'orange', 'yellow', 'green', 'blue')[random.randint(0, 4)]
self.canvas.create_rectangle(x0, y0, x1, y1, fill=color, activefill='black')
self.show_image()
def scroll_y(self, *args, **kwargs):
''' Scroll canvas vertically and redraw the image '''
self.canvas.yview(*args, **kwargs) # scroll vertically
self.show_image() # redraw the image
def scroll_x(self, *args, **kwargs):
''' Scroll canvas horizontally and redraw the image '''
self.canvas.xview(*args, **kwargs) # scroll horizontally
self.show_image() # redraw the image
def move_from(self, event):
''' Remember previous coordinates for scrolling with the mouse '''
self.canvas.scan_mark(event.x, event.y)
def move_to(self, event):
''' Drag (move) canvas to the new position '''
self.canvas.scan_dragto(event.x, event.y, gain=1)
self.show_image() # redraw the image
def wheel(self, event):
''' Zoom with mouse wheel '''
x = self.canvas.canvasx(event.x)
y = self.canvas.canvasy(event.y)
bbox = self.canvas.bbox(self.container) # get image area
if bbox[0] < x < bbox[2] and bbox[1] < y < bbox[3]: pass # Ok! Inside the image
else: return # zoom only inside image area
scale = 1.0
# Respond to Linux (event.num) or Windows (event.delta) wheel event
if event.num == 5 or event.delta == -120: # scroll down
i = min(self.width, self.height)
if int(i * self.imscale) < 30: return # image is less than 30 pixels
self.imscale /= self.delta
scale /= self.delta
if event.num == 4 or event.delta == 120: # scroll up
i = min(self.canvas.winfo_width(), self.canvas.winfo_height())
if i < self.imscale: return # 1 pixel is bigger than the visible area
self.imscale *= self.delta
scale *= self.delta
self.canvas.scale('all', x, y, scale, scale) # rescale all canvas objects
self.show_image()
def show_image(self, event=None):
''' Show image on the Canvas '''
bbox1 = self.canvas.bbox(self.container) # get image area
# Remove 1 pixel shift at the sides of the bbox1
bbox1 = (bbox1[0] + 1, bbox1[1] + 1, bbox1[2] - 1, bbox1[3] - 1)
bbox2 = (self.canvas.canvasx(0), # get visible area of the canvas
self.canvas.canvasy(0),
self.canvas.canvasx(self.canvas.winfo_width()),
self.canvas.canvasy(self.canvas.winfo_height()))
bbox = [min(bbox1[0], bbox2[0]), min(bbox1[1], bbox2[1]), # get scroll region box
max(bbox1[2], bbox2[2]), max(bbox1[3], bbox2[3])]
if bbox[0] == bbox2[0] and bbox[2] == bbox2[2]: # whole image in the visible area
bbox[0] = bbox1[0]
bbox[2] = bbox1[2]
if bbox[1] == bbox2[1] and bbox[3] == bbox2[3]: # whole image in the visible area
bbox[1] = bbox1[1]
bbox[3] = bbox1[3]
self.canvas.configure(scrollregion=bbox) # set scroll region
x1 = max(bbox2[0] - bbox1[0], 0) # get coordinates (x1,y1,x2,y2) of the image tile
y1 = max(bbox2[1] - bbox1[1], 0)
x2 = min(bbox2[2], bbox1[2]) - bbox1[0]
y2 = min(bbox2[3], bbox1[3]) - bbox1[1]
if int(x2 - x1) > 0 and int(y2 - y1) > 0: # show image if it in the visible area
x = min(int(x2 / self.imscale), self.width) # sometimes it is larger on 1 pixel...
y = min(int(y2 / self.imscale), self.height) # ...and sometimes not
image = self.image.crop((int(x1 / self.imscale), int(y1 / self.imscale), x, y))
imagetk = ImageTk.PhotoImage(image.resize((int(x2 - x1), int(y2 - y1))))
imageid = self.canvas.create_image(max(bbox2[0], bbox1[0]), max(bbox2[1], bbox1[1]),
anchor='nw', image=imagetk)
self.canvas.lower(imageid) # set image into background
self.canvas.imagetk = imagetk # keep an extra reference to prevent garbage-collection
path = 'doge.jpg' # place path to your image here
root = tk.Tk()
app = Zoom_Advanced(root, path=path)
root.mainloop()
MODIFIER:
J'ai créé un zoom encore plus avancé. Il existe une "pyramide d'images" pour un zoom fluide sur de grandes images et même la possibilité d'ouvrir et de zoomer d'énormes fichiers TIFF jusqu'à plusieurs gigaoctets.
La version 3.0 est testée sur Windows 7 64 bits et Python 3.7.
# -*- coding: utf-8 -*-
# Advanced zoom for images of various types from small to huge up to several GB
import math
import warnings
import tkinter as tk
from tkinter import ttk
from PIL import Image, ImageTk
class AutoScrollbar(ttk.Scrollbar):
""" A scrollbar that hides itself if it's not needed. Works only for grid geometry manager """
def set(self, lo, hi):
if float(lo) <= 0.0 and float(hi) >= 1.0:
self.grid_remove()
else:
self.grid()
ttk.Scrollbar.set(self, lo, hi)
def pack(self, **kw):
raise tk.TclError('Cannot use pack with the widget ' + self.__class__.__name__)
def place(self, **kw):
raise tk.TclError('Cannot use place with the widget ' + self.__class__.__name__)
class CanvasImage:
""" Display and zoom image """
def __init__(self, placeholder, path):
""" Initialize the ImageFrame """
self.imscale = 1.0 # scale for the canvas image zoom, public for outer classes
self.__delta = 1.3 # zoom magnitude
self.__filter = Image.ANTIALIAS # could be: NEAREST, BILINEAR, BICUBIC and ANTIALIAS
self.__previous_state = 0 # previous state of the keyboard
self.path = path # path to the image, should be public for outer classes
# Create ImageFrame in placeholder widget
self.__imframe = ttk.Frame(placeholder) # placeholder of the ImageFrame object
# Vertical and horizontal scrollbars for canvas
hbar = AutoScrollbar(self.__imframe, orient='horizontal')
vbar = AutoScrollbar(self.__imframe, orient='vertical')
hbar.grid(row=1, column=0, sticky='we')
vbar.grid(row=0, column=1, sticky='ns')
# Create canvas and bind it with scrollbars. Public for outer classes
self.canvas = tk.Canvas(self.__imframe, highlightthickness=0,
xscrollcommand=hbar.set, yscrollcommand=vbar.set)
self.canvas.grid(row=0, column=0, sticky='nswe')
self.canvas.update() # wait till canvas is created
hbar.configure(command=self.__scroll_x) # bind scrollbars to the canvas
vbar.configure(command=self.__scroll_y)
# Bind events to the Canvas
self.canvas.bind('<Configure>', lambda event: self.__show_image()) # canvas is resized
self.canvas.bind('<ButtonPress-1>', self.__move_from) # remember canvas position
self.canvas.bind('<B1-Motion>', self.__move_to) # move canvas to the new position
self.canvas.bind('<MouseWheel>', self.__wheel) # zoom for Windows and MacOS, but not Linux
self.canvas.bind('<Button-5>', self.__wheel) # zoom for Linux, wheel scroll down
self.canvas.bind('<Button-4>', self.__wheel) # zoom for Linux, wheel scroll up
# Handle keystrokes in idle mode, because program slows down on a weak computers,
# when too many key stroke events in the same time
self.canvas.bind('<Key>', lambda event: self.canvas.after_idle(self.__keystroke, event))
# Decide if this image huge or not
self.__huge = False # huge or not
self.__huge_size = 14000 # define size of the huge image
self.__band_width = 1024 # width of the tile band
Image.MAX_IMAGE_PIXELS = 1000000000 # suppress DecompressionBombError for the big image
with warnings.catch_warnings(): # suppress DecompressionBombWarning
warnings.simplefilter('ignore')
self.__image = Image.open(self.path) # open image, but down't load it
self.imwidth, self.imheight = self.__image.size # public for outer classes
if self.imwidth * self.imheight > self.__huge_size * self.__huge_size and \
self.__image.tile[0][0] == 'raw': # only raw images could be tiled
self.__huge = True # image is huge
self.__offset = self.__image.tile[0][2] # initial tile offset
self.__tile = [self.__image.tile[0][0], # it have to be 'raw'
[0, 0, self.imwidth, 0], # tile extent (a rectangle)
self.__offset,
self.__image.tile[0][3]] # list of arguments to the decoder
self.__min_side = min(self.imwidth, self.imheight) # get the smaller image side
# Create image pyramid
self.__pyramid = [self.smaller()] if self.__huge else [Image.open(self.path)]
# Set ratio coefficient for image pyramid
self.__ratio = max(self.imwidth, self.imheight) / self.__huge_size if self.__huge else 1.0
self.__curr_img = 0 # current image from the pyramid
self.__scale = self.imscale * self.__ratio # image pyramide scale
self.__reduction = 2 # reduction degree of image pyramid
w, h = self.__pyramid[-1].size
while w > 512 and h > 512: # top pyramid image is around 512 pixels in size
w /= self.__reduction # divide on reduction degree
h /= self.__reduction # divide on reduction degree
self.__pyramid.append(self.__pyramid[-1].resize((int(w), int(h)), self.__filter))
# Put image into container rectangle and use it to set proper coordinates to the image
self.container = self.canvas.create_rectangle((0, 0, self.imwidth, self.imheight), width=0)
self.__show_image() # show image on the canvas
self.canvas.focus_set() # set focus on the canvas
def smaller(self):
""" Resize image proportionally and return smaller image """
w1, h1 = float(self.imwidth), float(self.imheight)
w2, h2 = float(self.__huge_size), float(self.__huge_size)
aspect_ratio1 = w1 / h1
aspect_ratio2 = w2 / h2 # it equals to 1.0
if aspect_ratio1 == aspect_ratio2:
image = Image.new('RGB', (int(w2), int(h2)))
k = h2 / h1 # compression ratio
w = int(w2) # band length
Elif aspect_ratio1 > aspect_ratio2:
image = Image.new('RGB', (int(w2), int(w2 / aspect_ratio1)))
k = h2 / w1 # compression ratio
w = int(w2) # band length
else: # aspect_ratio1 < aspect_ration2
image = Image.new('RGB', (int(h2 * aspect_ratio1), int(h2)))
k = h2 / h1 # compression ratio
w = int(h2 * aspect_ratio1) # band length
i, j, n = 0, 1, round(0.5 + self.imheight / self.__band_width)
while i < self.imheight:
print('\rOpening image: {j} from {n}'.format(j=j, n=n), end='')
band = min(self.__band_width, self.imheight - i) # width of the tile band
self.__tile[1][3] = band # set band width
self.__tile[2] = self.__offset + self.imwidth * i * 3 # tile offset (3 bytes per pixel)
self.__image.close()
self.__image = Image.open(self.path) # reopen / reset image
self.__image.size = (self.imwidth, band) # set size of the tile band
self.__image.tile = [self.__tile] # set tile
cropped = self.__image.crop((0, 0, self.imwidth, band)) # crop tile band
image.paste(cropped.resize((w, int(band * k)+1), self.__filter), (0, int(i * k)))
i += band
j += 1
print('\r' + 30*' ' + '\r', end='') # hide printed string
return image
def redraw_figures(self):
""" Dummy function to redraw figures in the children classes """
pass
def grid(self, **kw):
""" Put CanvasImage widget on the parent widget """
self.__imframe.grid(**kw) # place CanvasImage widget on the grid
self.__imframe.grid(sticky='nswe') # make frame container sticky
self.__imframe.rowconfigure(0, weight=1) # make canvas expandable
self.__imframe.columnconfigure(0, weight=1)
def pack(self, **kw):
""" Exception: cannot use pack with this widget """
raise Exception('Cannot use pack with the widget ' + self.__class__.__name__)
def place(self, **kw):
""" Exception: cannot use place with this widget """
raise Exception('Cannot use place with the widget ' + self.__class__.__name__)
# noinspection PyUnusedLocal
def __scroll_x(self, *args, **kwargs):
""" Scroll canvas horizontally and redraw the image """
self.canvas.xview(*args) # scroll horizontally
self.__show_image() # redraw the image
# noinspection PyUnusedLocal
def __scroll_y(self, *args, **kwargs):
""" Scroll canvas vertically and redraw the image """
self.canvas.yview(*args) # scroll vertically
self.__show_image() # redraw the image
def __show_image(self):
""" Show image on the Canvas. Implements correct image zoom almost like in Google Maps """
box_image = self.canvas.coords(self.container) # get image area
box_canvas = (self.canvas.canvasx(0), # get visible area of the canvas
self.canvas.canvasy(0),
self.canvas.canvasx(self.canvas.winfo_width()),
self.canvas.canvasy(self.canvas.winfo_height()))
box_img_int = Tuple(map(int, box_image)) # convert to integer or it will not work properly
# Get scroll region box
box_scroll = [min(box_img_int[0], box_canvas[0]), min(box_img_int[1], box_canvas[1]),
max(box_img_int[2], box_canvas[2]), max(box_img_int[3], box_canvas[3])]
# Horizontal part of the image is in the visible area
if box_scroll[0] == box_canvas[0] and box_scroll[2] == box_canvas[2]:
box_scroll[0] = box_img_int[0]
box_scroll[2] = box_img_int[2]
# Vertical part of the image is in the visible area
if box_scroll[1] == box_canvas[1] and box_scroll[3] == box_canvas[3]:
box_scroll[1] = box_img_int[1]
box_scroll[3] = box_img_int[3]
# Convert scroll region to Tuple and to integer
self.canvas.configure(scrollregion=Tuple(map(int, box_scroll))) # set scroll region
x1 = max(box_canvas[0] - box_image[0], 0) # get coordinates (x1,y1,x2,y2) of the image tile
y1 = max(box_canvas[1] - box_image[1], 0)
x2 = min(box_canvas[2], box_image[2]) - box_image[0]
y2 = min(box_canvas[3], box_image[3]) - box_image[1]
if int(x2 - x1) > 0 and int(y2 - y1) > 0: # show image if it in the visible area
if self.__huge and self.__curr_img < 0: # show huge image
h = int((y2 - y1) / self.imscale) # height of the tile band
self.__tile[1][3] = h # set the tile band height
self.__tile[2] = self.__offset + self.imwidth * int(y1 / self.imscale) * 3
self.__image.close()
self.__image = Image.open(self.path) # reopen / reset image
self.__image.size = (self.imwidth, h) # set size of the tile band
self.__image.tile = [self.__tile]
image = self.__image.crop((int(x1 / self.imscale), 0, int(x2 / self.imscale), h))
else: # show normal image
image = self.__pyramid[max(0, self.__curr_img)].crop( # crop current img from pyramid
(int(x1 / self.__scale), int(y1 / self.__scale),
int(x2 / self.__scale), int(y2 / self.__scale)))
#
imagetk = ImageTk.PhotoImage(image.resize((int(x2 - x1), int(y2 - y1)), self.__filter))
imageid = self.canvas.create_image(max(box_canvas[0], box_img_int[0]),
max(box_canvas[1], box_img_int[1]),
anchor='nw', image=imagetk)
self.canvas.lower(imageid) # set image into background
self.canvas.imagetk = imagetk # keep an extra reference to prevent garbage-collection
def __move_from(self, event):
""" Remember previous coordinates for scrolling with the mouse """
self.canvas.scan_mark(event.x, event.y)
def __move_to(self, event):
""" Drag (move) canvas to the new position """
self.canvas.scan_dragto(event.x, event.y, gain=1)
self.__show_image() # zoom tile and show it on the canvas
def outside(self, x, y):
""" Checks if the point (x,y) is outside the image area """
bbox = self.canvas.coords(self.container) # get image area
if bbox[0] < x < bbox[2] and bbox[1] < y < bbox[3]:
return False # point (x,y) is inside the image area
else:
return True # point (x,y) is outside the image area
def __wheel(self, event):
""" Zoom with mouse wheel """
x = self.canvas.canvasx(event.x) # get coordinates of the event on the canvas
y = self.canvas.canvasy(event.y)
if self.outside(x, y): return # zoom only inside image area
scale = 1.0
# Respond to Linux (event.num) or Windows (event.delta) wheel event
if event.num == 5 or event.delta == -120: # scroll down, smaller
if round(self.__min_side * self.imscale) < 30: return # image is less than 30 pixels
self.imscale /= self.__delta
scale /= self.__delta
if event.num == 4 or event.delta == 120: # scroll up, bigger
i = min(self.canvas.winfo_width(), self.canvas.winfo_height()) >> 1
if i < self.imscale: return # 1 pixel is bigger than the visible area
self.imscale *= self.__delta
scale *= self.__delta
# Take appropriate image from the pyramid
k = self.imscale * self.__ratio # temporary coefficient
self.__curr_img = min((-1) * int(math.log(k, self.__reduction)), len(self.__pyramid) - 1)
self.__scale = k * math.pow(self.__reduction, max(0, self.__curr_img))
#
self.canvas.scale('all', x, y, scale, scale) # rescale all objects
# Redraw some figures before showing image on the screen
self.redraw_figures() # method for child classes
self.__show_image()
def __keystroke(self, event):
""" Scrolling with the keyboard.
Independent from the language of the keyboard, CapsLock, <Ctrl>+<key>, etc. """
if event.state - self.__previous_state == 4: # means that the Control key is pressed
pass # do nothing if Control key is pressed
else:
self.__previous_state = event.state # remember the last keystroke state
# Up, Down, Left, Right keystrokes
if event.keycode in [68, 39, 102]: # scroll right, keys 'd' or 'Right'
self.__scroll_x('scroll', 1, 'unit', event=event)
Elif event.keycode in [65, 37, 100]: # scroll left, keys 'a' or 'Left'
self.__scroll_x('scroll', -1, 'unit', event=event)
Elif event.keycode in [87, 38, 104]: # scroll up, keys 'w' or 'Up'
self.__scroll_y('scroll', -1, 'unit', event=event)
Elif event.keycode in [83, 40, 98]: # scroll down, keys 's' or 'Down'
self.__scroll_y('scroll', 1, 'unit', event=event)
def crop(self, bbox):
""" Crop rectangle from the image and return it """
if self.__huge: # image is huge and not totally in RAM
band = bbox[3] - bbox[1] # width of the tile band
self.__tile[1][3] = band # set the tile height
self.__tile[2] = self.__offset + self.imwidth * bbox[1] * 3 # set offset of the band
self.__image.close()
self.__image = Image.open(self.path) # reopen / reset image
self.__image.size = (self.imwidth, band) # set size of the tile band
self.__image.tile = [self.__tile]
return self.__image.crop((bbox[0], 0, bbox[2], band))
else: # image is totally in RAM
return self.__pyramid[0].crop(bbox)
def destroy(self):
""" ImageFrame destructor """
self.__image.close()
map(lambda i: i.close, self.__pyramid) # close all pyramid images
del self.__pyramid[:] # delete pyramid list
del self.__pyramid # delete pyramid variable
self.canvas.destroy()
self.__imframe.destroy()
class MainWindow(ttk.Frame):
""" Main window class """
def __init__(self, mainframe, path):
""" Initialize the main Frame """
ttk.Frame.__init__(self, master=mainframe)
self.master.title('Advanced Zoom v3.0')
self.master.geometry('800x600') # size of the main window
self.master.rowconfigure(0, weight=1) # make the CanvasImage widget expandable
self.master.columnconfigure(0, weight=1)
canvas = CanvasImage(self.master, path) # create widget
canvas.grid(row=0, column=0) # show widget
filename = './data/img_plg5.png' # place path to your image here
#filename = 'd:/Data/yandex_z18_1-1.tif' # huge TIFF file 1.4 GB
#filename = 'd:/Data/The_Garden_of_Earthly_Delights_by_Bosch_High_Resolution.jpg'
#filename = 'd:/Data/The_Garden_of_Earthly_Delights_by_Bosch_High_Resolution.tif'
#filename = 'd:/Data/heic1502a.tif'
#filename = 'd:/Data/land_shallow_topo_east.tif'
#filename = 'd:/Data/X1D5_B0002594.3FR'
app = MainWindow(tk.Tk(), path=filename)
app.mainloop()
P.S. Voici l'application GitHub utilisant un zoom avancé pour annotation manuelle des images avec des polygones .
Vous pourriez envisager d'utiliser des tuiles de carte pour ce cas. Les tuiles peuvent être spécifiques au niveau de zoom. Après avoir sélectionné les tuiles en fonction du niveau de panoramique et de zoom, vous pouvez les positionner sur la toile avec Canvas.create_image.
En supposant que vous ayez une classe de tuiles avec ses coordonnées et son image, vous pouvez sélectionner des tuiles visibles en fonction du panoramique, du zoom et de la taille du cadre.
for tile in visible_tiles(pan_center, frame_dimensions, zoom_level):
canvas.create_image(tile.x, tile.y, anchor=Tkinter.NW, image=tile.image)
Vous en trouverez un exemple complet dans Tile-Based Geospatial Information Systems de John Sample et Elias Ioup dans le chapitre sur les clients de mappage en mosaïque.
Le mécanisme fondamental pour prendre en charge le zoom (avec la molette) et le mouvement/panoramique (avec le bouton gauche) est le suivant:
from tkinter import ALL, EventType
canvas.bind("<MouseWheel>", do_zoom)
canvas.bind('<ButtonPress-1>', lambda event: canvas.scan_mark(event.x, event.y))
canvas.bind("<B1-Motion>", lambda event: canvas.scan_dragto(event.x, event.y, gain=1))
def do_zoom(event):
factor = 1.001 ** event.delta
canvas.scale(ALL, event.x, event.y, factor, factor)
Extension simple: supporte le zoom de chaque axe individuellement, en regardant l'état de Ctrl et Shift, comme suit:
def do_zoom(event):
factor = 1.001 ** event.delta
is_shift = event.state & (1 << 0) != 0
is_ctrl = event.state & (1 << 2) != 0
canvas.scale(ALL, event.x, event.y,
factor if not is_shift else 1.0,
factor if not is_ctrl else 1.0)