Python 入门基础知识 - 多媒体编程 - PIL处理图片之生成缩略图

生成缩略图

使用PIL生成缩略图主要是使用Image的size函数。使用size函数可以重新指定图片的大小，代码实例如下，使用PIL模块批量生成图片缩略图

# _*_ coding: utf-8 -*-
# version 2.7.13

import os
from PIL import Image
import Tkinter
import tkFileDialog
import tkMessageBox


class Window:
    def __init__(self):
        self.root = root = Tkinter.Tk()
        self.Image = Tkinter.StringVar()
        self.status = Tkinter.StringVar()
        self.mstatus = Tkinter.IntVar()
        self.fstatus = Tkinter.IntVar()
        self.Image.set('bmp')
        self.mstatus.set(0)
        self.fstatus.set(0)
        label = Tkinter.Label(root, text='输入百分比')
        label.place(x=5, y=5)
        self.entryNew = Tkinter.Entry(root)
        self.entryNew.place(x=65, y=5)
        self.checkM = Tkinter.Checkbutton(root, text='批量转换',
                                          command=self.OnCheckM,
                                          variable=self.mstatus,
                                          onvalue=1,
                                          offvalue=0)
        self.checkM.place(x=5, y=30)
        label = Tkinter.Label(root, text='选择文件')
        label.place(x=5, y=55)
        self.entryFile = Tkinter.Entry(root)
        self.entryFile.place(x=55, y=55)
        self.buttonBrowserFile = Tkinter.Button(root, text='浏览',
                                                command=self.BrowserFile)
        self.buttonBrowserFile.place(x=200, y=55)
        label = Tkinter.Label(root, text='选择目录')
        label.place(x=5, y=80)
        self.entryDir = Tkinter.Entry(root, state=Tkinter.DISABLED)
        self.entryDir.place(x=55, y=80)
        self.buttonBrowserDir = Tkinter.Button(root, text='浏览',
                                               command=self.BrowserDir,
                                               state=Tkinter.DISABLED)
        self.buttonBrowserDir.place(x=200, y=80)
        self.checkF = Tkinter.Checkbutton(root, text='改变文件格式',
                                          command=self.OnCheckF,
                                          variable=self.fstatus,
                                          onvalue=1,
                                          offvalue=0)
        self.checkF.place(x=5, y=110)
        frame = Tkinter.Frame(root)
        frame.place(x=10, y=130)
        labelTo = Tkinter.Label(frame, text='To')
        labelTo.pack(anchor='w')
        self.rBmp = Tkinter.Radiobutton(frame, variable=self.Image,
                                        value='bmp',
                                        text='BMP',
                                        state=Tkinter.DISABLED)
        self.rBmp.pack(anchor='w')
        self.rJpg = Tkinter.Radiobutton(frame, variable=self.Image,
                                        value='jpg',
                                        text='JPG',
                                        state=Tkinter.DISABLED)
        self.rJpg.pack(anchor='w')
        self.rGif = Tkinter.Radiobutton(frame, variable=self.Image,
                                        value='gif',
                                        text='GIF',
                                        state=Tkinter.DISABLED)
        self.rGif.pack(anchor='w')
        self.rPng = Tkinter.Radiobutton(frame, variable=self.Image,
                                        value='png',
                                        text='PNG',
                                        state=Tkinter.DISABLED)
        self.rPng.pack(anchor='w')
        self.buttonConv = Tkinter.Button(root, text='转换', command=self.Conv)
        self.buttonConv.place(x=100, y=175)
        self.labelStatus = Tkinter.Label(root, textvariable=self.status)
        self.labelStatus.place(x=80, y=205)
    
    def MainLoop(self): # 进入消息循环
        self.root.minsize(250, 250)
        self.root.maxsize(250, 250)
        self.root.mainloop()

    def BrowserDir(self):
        directory = tkFileDialog.askdirectory(title='Python')
        if directory:
            self.entryDir.delete(0, Tkinter.END)
            self.entryDir.insert(Tkinter.END, directory)

    def BrowserFile(self):
        file = tkFileDialog.askopenfilename(title='Python Music Player', filetypes=[('JPG','*.jpg'),('BMP', '*.bmp'),('PNG', '*.png'),('GIF', '*.gif')])
        if file:
            self.entryFile.delete(0, Tkinter.END)
            self.entryFile.insert(Tkinter.END, file)
    
    def OnCheckM(self): # 设置组件状态
        if not self.mstatus.get():
            self.entryDir.config(state=Tkinter.DISABLED)
            self.entryFile.config(state=Tkinter.NORMAL)
            self.buttonBrowserDir.config(state=Tkinter.DISABLED)
            self.buttonBrowserFile.config(state=Tkinter.NORMAL)
        else:
            self.entryDir.config(state=Tkinter.NORMAL)
            self.entryFile.config(state=Tkinter.DISABLED)
            self.buttonBrowserDir.config(state=Tkinter.NORMAL)
            self.buttonBrowserFile.config(state=Tkinter.DISABLED)

    def OnCheckF(self): # 设置组件状态
        if not self.fstatus.get():
            self.rBmp.config(state=Tkinter.DISABLED)
            self.rJpg.config(state=Tkinter.DISABLED)
            self.rGif.config(state=Tkinter.DISABLED)
            self.rPng.config(state=Tkinter.DISABLED)
        else:
            self.rBmp.config(state=Tkinter.NORMAL)
            self.rJpg.config(state=Tkinter.NORMAL)
            self.rGif.config(state=Tkinter.NORMAL)
            self.rPng.config(state=Tkinter.NORMAL)

    def Conv(self):
        n = 0
        if self.mstatus.get():
            path = self.entryDir.get()
            if path == '':
                tkMessageBox.showerror('Python Tkinter', '请输入路径')
                return

            filenames = os.listdir()
            if self.fstatus.get():
                f = self.Image.get()
                for filename in filenames:
                    if filename[-3:] in ('bmp','jpg','gif','png'):
                        self.make(path + '/' + filename, f)
                    n = n + 1
            else:
                for filename in filenames:
                    if filename[-3:] in ('bmp', 'jpg', 'gif', 'png'):
                        self.make(path + '/' + filename)
                    n = n + 1
        else:
            file = self.entryFile.get()
            if file == '':
                tkMessageBox.showerror('Python Tkinter', '请选择文件')
                return

            if self.fstatus.get():
                f = self.Image.get()
                self.make(file, f)
                n = n + 1
            else:
                self.make(file)
                n = n + 1

        self.status.set('成功转换%d图片' % n)

    def make(self, file, format=None):
        im = Image.open(file)
        mode = im.mode
        if mode not in ('L', 'RGB'):
            im = im.convert('RGB')

        width, height = im.size
        s = self.entryNew.get()
        if s == '':
            tkMessageBox.showerror('Python Tkinter', '请输入百分比')
            return
        else:
            n = int(s)

        nwidth = width * n / 100
        nheight = height * n / 100
        thumb = im.resize((nwidth, nheight), Image.ANTIALIAS)
        if format:
            thumb.save(file[:len(file)-4] + '_thumb.' + format)
        else:
            thumb.save(file[:len(file)-4] + '_thumb' + file[-4:])


window = Window()
window.MainLoop()

执行后的结果如下