当tkinter里的一个组件是图像时，如果允许缩放主窗口的同时，让图像也缩放，有时候是一种需求。
主要实现方法是bind一个回调函数。这里的例子是，图像上绘制了矩形框，当窗口被用鼠标缩放时，图像缩放，框也缩放。
# coding: utf-8
"""
Demonstrates how to resizing tkinter windows and image on it
https://cloud.tencent.com/developer/article/1430998
https://stackoverflow.com/questions/7299955/tkinter-binding-a-function-with-arguments-to-a-widget
"""
import tkinter as tk
from PIL import Image, ImageTk
import cv2
class App(tk.Tk):
def __init__(self):
super().__init__()
self.lbPic = tk.Label(self, text='test', width=400, height=600)
self.im_orig = cv2.imread('E:/data/VOC2007/JPEGImages/000001.jpg')
self.xmin_orig = 8
self.ymin_orig = 12
self.xmax_orig = 352
self.ymax_orig = 498
cv2.rectangle(
self.im_orig,
pt1 = (self.xmin_orig, self.ymin_orig),
pt2 = (self.xmax_orig, self.ymax_orig),
color = (0, 255, 0),
thickness = 2
)
self.im_orig = self.im_orig[:, :, ::-1] # bgr => rgb necessary
tkim = ImageTk.PhotoImage(Image.fromarray(self.im_orig))
self.lbPic['image'] = tkim
self.lbPic.image = tkim
self.lbPic.bind('<Configure>', self.changeSize)
self.lbPic.pack(fill=tk.BOTH, expand=tk.YES)
def changeSize(self, event):
im = cv2.resize(self.im_orig, (event.width, event.height))
tkim = ImageTk.PhotoImage(Image.fromarray(im))
self.lbPic['image'] = tkim
self.lbPic.image = tkim
def main():
app = App()
app.title('缩放图像')
app.mainloop()
if __name__ == '__main__':
main()
不过在MacOSX下，上述代码显示有问题。改成如下：
import tkinter as tk
from PIL import Image, ImageTk
import cv2
class App(tk.Tk):
def __init__(self):
super().__init__()
self.geometry("800x600")
self.rowconfigure(0, weight=1)
self.columnconfigure(0, weight=1)
self.lbPic = tk.Label(self, text='test', compound='center')
self.im_orig = cv2.imread('/Users/chris/data/VOC2007/JPEGImages/000001.jpg')
self.xmin_orig = 8
self.ymin_orig = 12
self.xmax_orig = 352
self.ymax_orig = 498
cv2.rectangle(
self.im_orig,
pt1 = (self.xmin_orig, self.ymin_orig),
pt2 = (self.xmax_orig, self.ymax_orig),
color = (0, 255, 0),
thickness = 2
)
self.im_orig = self.im_orig[:, :, ::-1] # bgr => rgb necessary
tkim = ImageTk.PhotoImage(Image.fromarray(self.im_orig))
self.lbPic['image'] = tkim
self.lbPic.image = tkim
self.lbPic.bind('<Configure>', self.changeSize)
self.lbPic.grid(row=0, column=0, sticky=tk.NSEW)
def changeSize(self, event):
im = cv2.resize(self.im_orig, (event.width, event.height))
tkim = ImageTk.PhotoImage(Image.fromarray(im))
self.lbPic['image'] = tkim
self.lbPic.image = tkim
def main():
app = App()
app.title('缩放图像')
app.mainloop()
if __name__ == '__main__':
main()