创建圆形图像PIL Tkinter

Question

目前我的应用程序中有一个缩放功能，效果很好，但是我希望实际缩放框是一个圆形。下面是目前变焦的样子：

放大后的矩形是当鼠标指针位置，和周围的区域被放大，但我怎么能做出这种放大对象的圆，而不是一个正方形？这里是我的代码：

def zoom(self, event): 
    if(event.delta > 0): 
     if self.zoomValue != 4 : self.zoomValue += 1 
    elif(event.delta < 0): 
     if self.zoomValue != 0 : self.zoomValue -= 1 
    self.crop(event) 

def crop(self, event): 
    if self.zimg_id: self.canvasLower.delete(self.zimg_id) 
    if (self.zoomValue) != 0: 
     x, y = event.x, event.y 
     if self.zoomValue == 1: 
      tmp = self.orig_img.crop((x-45, y-30, x+45, y+30)) 
     elif self.zoomValue == 2: 
      tmp = self.orig_img.crop((x-30, y-20, x+30, y+20)) 
     elif self.zoomValue == 3: 
      tmp = self.orig_img.crop((x-15, y-10, x+15, y+10)) 
     elif self.zoomValue == 4: 
      tmp = self.orig_img.crop((x-6, y-4, x+6, y+4)) 
     size = 200, 200 
     # crop tmp somehow to make the image a circle? maybe? 
     self.zimg = ImageTk.PhotoImage(tmp.resize(size)) 
     self.zimg_id = self.canvasLower.create_image(event.x, event.y, image=self.zimg) 

Answer 1

从this answer适应（你需要ImageOps和ImageDraw从PIL进口），您可以使用您的放大图像创建一个圆形掩蔽：

def create_mask(self): 
    self.mask = Image.new('L', (200,200), 0) 
    draw = ImageDraw.Draw(self.mask) 
    draw.ellipse((0, 0) + self.mask.size, fill=255) 

然后，你必须申请面膜在你crop功能：

output = ImageOps.fit(tmp, self.mask.size, centering=(0.5, 0.5)) 
output.putalpha(self.mask) 
self.zimg = ImageTk.PhotoImage(output) 

---

作为参考，一个完整的工作的例子是这样的：

import Tkinter as tk 
from PIL import Image, ImageTk, ImageOps, ImageDraw 

class App(): 
    def __init__(self, master, image_path): 
     self.orig_img = Image.open(image_path) 
     self.tk_img = ImageTk.PhotoImage(self.orig_img) 

     w, h = self.orig_img.size 
     self.canvas = tk.Canvas(master, width=w, height=h) 
     self.canvas.pack() 

     self.canvas.create_image(0, 0, image=self.tk_img, anchor='nw') 
     self.canvas.bind_all("<MouseWheel>", self.zoom) 
     self.canvas.bind_all("<Motion>", self.crop) 

     self.create_mask() 
     self.zoomValue = 0 
     self.zimg_id = None 

    def create_mask(self): 
     self.mask = Image.new('L', (200,200), 0) 
     draw = ImageDraw.Draw(self.mask) 
     draw.ellipse((0, 0) + self.mask.size, fill=255)   

    def zoom(self, event): 
     if(event.delta > 0): 
      if self.zoomValue != 4 : self.zoomValue += 1 
     elif(event.delta < 0): 
      if self.zoomValue != 0 : self.zoomValue -= 1 
     self.crop(event) 

    def crop(self, event): 
     if self.zimg_id: self.canvas.delete(self.zimg_id) 

     if (self.zoomValue) != 0: 
      x, y = event.x, event.y 
      if self.zoomValue == 1: 
       tmp = self.orig_img.crop((x-45, y-30, x+45, y+30)) 
      elif self.zoomValue == 2: 
       tmp = self.orig_img.crop((x-30, y-20, x+30, y+20)) 
      elif self.zoomValue == 3: 
       tmp = self.orig_img.crop((x-15, y-10, x+15, y+10)) 
      elif self.zoomValue == 4: 
       tmp = self.orig_img.crop((x-6, y-4, x+6, y+4)) 

      output = ImageOps.fit(tmp, self.mask.size, centering=(0.5, 0.5)) 
      output.putalpha(self.mask) 
      self.zimg = ImageTk.PhotoImage(output) 
      self.zimg_id = self.canvas.create_image(event.x, event.y, image=self.zimg) 

root = tk.Tk() 
App(root, r'C:\Users\user\Desktop\bg.gif') 
root.mainloop()