将图像平移到画布中心python_python–Tkinter画布缩放移动/平移

高级缩放示例.就像谷歌地图一样.

它仅缩放图块,但不缩放整个图像.因此,缩放的瓷砖占据了恒定的记忆,并且不会为大型缩放图像调整大小的图像.对于简化的缩放示例look here.

在Windows 7 64位和Python 3.6.2上测试.

不要忘记在脚本末尾放置图像路径.

# -*- 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):

&＃39;&＃39;&＃39; A scrollbar that hides itself if it&＃39;s not needed.

Works only if you use the grid geometry manager &＃39;&＃39;&＃39;

def set(self, lo, hi):

if float(lo) <&＃61; 0.0 and float(hi) >&＃61; 1.0:

self.grid_remove()

else:

self.grid()

ttk.Scrollbar.set(self, lo, hi)

def pack(self, **kw):

raise tk.TclError(&＃39;Cannot use pack with this widget&＃39;)

def place(self, **kw):

raise tk.TclError(&＃39;Cannot use place with this widget&＃39;)

class Zoom_Advanced(ttk.Frame):

&＃39;&＃39;&＃39; Advanced zoom of the image &＃39;&＃39;&＃39;

def __init__(self, mainframe, path):

&＃39;&＃39;&＃39; Initialize the main Frame &＃39;&＃39;&＃39;

ttk.Frame.__init__(self, master&＃61;mainframe)

self.master.title(&＃39;Zoom with mouse wheel&＃39;)

# Vertical and horizontal scrollbars for canvas

vbar &＃61; AutoScrollbar(self.master, orient&＃61;&＃39;vertical&＃39;)

hbar &＃61; AutoScrollbar(self.master, orient&＃61;&＃39;horizontal&＃39;)

vbar.grid(row&＃61;0, column&＃61;1, sticky&＃61;&＃39;ns&＃39;)

hbar.grid(row&＃61;1, column&＃61;0, sticky&＃61;&＃39;we&＃39;)

# Create canvas and put image on it

self.canvas &＃61; tk.Canvas(self.master, highlightthickness&＃61;0,

xscrollcommand&＃61;hbar.set, yscrollcommand&＃61;vbar.set)

self.canvas.grid(row&＃61;0, column&＃61;0, sticky&＃61;&＃39;nswe&＃39;)

self.canvas.update() # wait till canvas is created

vbar.configure(command&＃61;self.scroll_y) # bind scrollbars to the canvas

hbar.configure(command&＃61;self.scroll_x)

# Make the canvas expandable

self.master.rowconfigure(0, weight&＃61;1)

self.master.columnconfigure(0, weight&＃61;1)

# Bind events to the Canvas

self.canvas.bind(&＃39;&＃39;, self.show_image) # canvas is resized

self.canvas.bind(&＃39;&＃39;, self.move_from)

self.canvas.bind(&＃39;&＃39;, self.move_to)

self.canvas.bind(&＃39;&＃39;, self.wheel) # with Windows and MacOS, but not Linux

self.canvas.bind(&＃39;&＃39;, self.wheel) # only with Linux, wheel scroll down

self.canvas.bind(&＃39;&＃39;, self.wheel) # only with Linux, wheel scroll up

self.image &＃61; Image.open(path) # open image

self.width, self.height &＃61; self.image.size

self.imscale &＃61; 1.0 # scale for the canvaas image

self.delta &＃61; 1.3 # zoom magnitude

# Put image into container rectangle and use it to set proper coordinates to the image

self.container &＃61; self.canvas.create_rectangle(0, 0, self.width, self.height, width&＃61;0)

# Plot some optional random rectangles for the test purposes

minsize, maxsize, number &＃61; 5, 20, 10

for n in range(number):

x0 &＃61; random.randint(0, self.width - maxsize)

y0 &＃61; random.randint(0, self.height - maxsize)

x1 &＃61; x0 &＃43; random.randint(minsize, maxsize)

y1 &＃61; y0 &＃43; random.randint(minsize, maxsize)

color &＃61; (&＃39;red&＃39;, &＃39;orange&＃39;, &＃39;yellow&＃39;, &＃39;green&＃39;, &＃39;blue&＃39;)[random.randint(0, 4)]

self.canvas.create_rectangle(x0, y0, x1, y1, fill&＃61;color, activefill&＃61;&＃39;black&＃39;)

self.show_image()

def scroll_y(self, *args, **kwargs):

&＃39;&＃39;&＃39; Scroll canvas vertically and redraw the image &＃39;&＃39;&＃39;

self.canvas.yview(*args, **kwargs) # scroll vertically

self.show_image() # redraw the image

def scroll_x(self, *args, **kwargs):

&＃39;&＃39;&＃39; Scroll canvas horizontally and redraw the image &＃39;&＃39;&＃39;

self.canvas.xview(*args, **kwargs) # scroll horizontally

self.show_image() # redraw the image

def move_from(self, event):

&＃39;&＃39;&＃39; Remember previous coordinates for scrolling with the mouse &＃39;&＃39;&＃39;

self.canvas.scan_mark(event.x, event.y)

def move_to(self, event):

&＃39;&＃39;&＃39; Drag (move) canvas to the new position &＃39;&＃39;&＃39;

self.canvas.scan_dragto(event.x, event.y, gain&＃61;1)

self.show_image() # redraw the image

def wheel(self, event):

&＃39;&＃39;&＃39; Zoom with mouse wheel &＃39;&＃39;&＃39;

x &＃61; self.canvas.canvasx(event.x)

y &＃61; self.canvas.canvasy(event.y)

bbox &＃61; self.canvas.bbox(self.container) # get image area

if bbox[0]

else: return # zoom only inside image area

scale &＃61; 1.0

# Respond to Linux (event.num) or Windows (event.delta) wheel event

if event.num &＃61;&＃61; 5 or event.delta &＃61;&＃61; -120: # scroll down

i &＃61; min(self.width, self.height)

if int(i * self.imscale) <30: return # image is less than 30 pixels

self.imscale /&＃61; self.delta

scale /&＃61; self.delta

if event.num &＃61;&＃61; 4 or event.delta &＃61;&＃61; 120: # scroll up

i &＃61; min(self.canvas.winfo_width(), self.canvas.winfo_height())

if i

self.imscale *&＃61; self.delta

scale *&＃61; self.delta

self.canvas.scale(&＃39;all&＃39;, x, y, scale, scale) # rescale all canvas objects

self.show_image()

def show_image(self, event&＃61;None):

&＃39;&＃39;&＃39; Show image on the Canvas &＃39;&＃39;&＃39;

bbox1 &＃61; self.canvas.bbox(self.container) # get image area

# Remove 1 pixel shift at the sides of the bbox1

bbox1 &＃61; (bbox1[0] &＃43; 1, bbox1[1] &＃43; 1, bbox1[2] - 1, bbox1[3] - 1)

bbox2 &＃61; (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 &＃61; [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] &＃61;&＃61; bbox2[0] and bbox[2] &＃61;&＃61; bbox2[2]: # whole image in the visible area

bbox[0] &＃61; bbox1[0]

bbox[2] &＃61; bbox1[2]

if bbox[1] &＃61;&＃61; bbox2[1] and bbox[3] &＃61;&＃61; bbox2[3]: # whole image in the visible area

bbox[1] &＃61; bbox1[1]

bbox[3] &＃61; bbox1[3]

self.canvas.configure(scrollregion&＃61;bbox) # set scroll region

x1 &＃61; max(bbox2[0] - bbox1[0], 0) # get coordinates (x1,y1,x2,y2) of the image tile

y1 &＃61; max(bbox2[1] - bbox1[1], 0)

x2 &＃61; min(bbox2[2], bbox1[2]) - bbox1[0]

y2 &＃61; 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 &＃61; min(int(x2 / self.imscale), self.width) # sometimes it is larger on 1 pixel...

y &＃61; min(int(y2 / self.imscale), self.height) # ...and sometimes not

image &＃61; self.image.crop((int(x1 / self.imscale), int(y1 / self.imscale), x, y))

imagetk &＃61; ImageTk.PhotoImage(image.resize((int(x2 - x1), int(y2 - y1))))

imageid &＃61; self.canvas.create_image(max(bbox2[0], bbox1[0]), max(bbox2[1], bbox1[1]),

anchor&＃61;&＃39;nw&＃39;, image&＃61;imagetk)

self.canvas.lower(imageid) # set image into background

self.canvas.imagetk &＃61; imagetk # keep an extra reference to prevent garbage-collection

path &＃61; &＃39;doge.jpg&＃39; # place path to your image here

root &＃61; tk.Tk()

app &＃61; Zoom_Advanced(root, path&＃61;path)

root.mainloop()