发布于 2015-10-19 09:25:58 | 172 次阅读 | 评论: 0 | 来源: 网友投递
Python编程语言
Python 是一种面向对象、解释型计算机程序设计语言，由Guido van Rossum于1989年底发明，第一个公开发行版发行于1991年。Python语法简洁而清晰，具有丰富和强大的类库。它常被昵称为胶水语言，它能够把用其他语言制作的各种模块（尤其是C/C++）很轻松地联结在一起。
本文实例讲述了python使用PIL缩放网络图片并保存的方法。分享给大家供大家参考。具体实现方法如下：
''' tk_image_view_url_io_resize.py
display an image from a URL using Tkinter, PIL and data_stream
also resize the web image to fit a certain size display widget
retaining its aspect ratio
Pil facilitates resizing and allows file formats other then gif
tested with Python27 and Python33 by vegaseat 18mar2013
'''
import io
from PIL import Image, ImageTk
try:
# Python2
import Tkinter as tk
from urllib2 import urlopen
except ImportError:
# Python3
import tkinter as tk
from urllib.request import urlopen
def resize(w, h, w_box, h_box, pil_image):
'''
resize a pil_image object so it will fit into
a box of size w_box times h_box, but retain aspect ratio
'''
f1 = 1.0*w_box/w # 1.0 forces float division in Python2
f2 = 1.0*h_box/h
factor = min([f1, f2])
#print(f1, f2, factor) # test
# use best down-sizing filter
width = int(w*factor)
height = int(h*factor)
return pil_image.resize((width, height), Image.ANTIALIAS)
root = tk.Tk()
# size of image display box you want
w_box = 400
h_box = 350
# find yourself a picture on an internet web page you like
# (right click on the picture, under properties copy the address)
# a larger (1600 x 1200) picture from the internet
# url name is long, so split it
url1 = "http://freeflowerpictures.net/image/flowers/petunia/"
url2 = "petunia-flower.jpg"
url = url1 + url2
image_bytes = urlopen(url).read()
# internal data file
data_stream = io.BytesIO(image_bytes)
# open as a PIL image object
pil_image = Image.open(data_stream)
# get the size of the image
w, h = pil_image.size
# resize the image so it retains its aspect ration
# but fits into the specified display box
pil_image_resized = resize(w, h, w_box, h_box, pil_image)
# optionally show resized image info ...
# get the size of the resized image
wr, hr = pil_image_resized.size
# split off image file name
fname = url.split('/')[-1]
sf = "resized {} ({}x{})".format(fname, wr, hr)
root.title(sf)
# convert PIL image object to Tkinter PhotoImage object
tk_image = ImageTk.PhotoImage(pil_image_resized)
# put the image on a widget the size of the specified display box
label = tk.Label(root, image=tk_image, width=w_box, height=h_box)
label.pack(padx=5, pady=5)
root.mainloop()