python使用Image处理图片常用技巧分析

使用python来处理图片是非常方便的，下面提供一小段python处理图片的代码，需要安装图像处理工具包PIL(Python Image Library)。

#coding=utf-8
import Image
import urllib2
import StringIO
import os
#改变图片大小
def resize_img(img_path):
  try:
    img = Image.open(img_path)
    (width,height) = img.size
    new_width = 200
    new_height = height * new_width / width
    out = img.resize((new_width,new_height),Image.ANTIALIAS)
    ext = os.path.splitext(img_path)[1]
    new_file_name = '%s%s' %('small',ext)
    out.save(new_file_name,quality=95)
  except Exception,e:
    print e
#改变图片类型
def change_img_type(img_path):
  try:
    img = Image.open(img_path)
    img.save('new_type.png')
  except Exception,e:
    print e
#处理远程图片
def handle_remote_img(img_url):
  try:
    request = urllib2.Request(img_url)
    img_data = urllib2.urlopen(request).read()
    img_buffer = StringIO.StringIO(img_data)
    img = Image.open(img_buffer)
    img.save('remote.jpg')
    (width,height) = img.size
    out = img.resize((200,height * 200 / width),Image.ANTIALIAS)
    out.save('remote_small.jpg')
  except Exception,e:
    print e
if __name__ == '__main__':
  img_path = 'test.jpg'
  resize_img(img_path)
  change_img_type(img_path)
  img_url = 'http://img.hb.aicdn.com/042f8a4a70239f724ff7b9fa0fc8edf18658f41022ada-WcItWE_fw554'
  handle_remote_img(img_url)

可能会遇到的问题

ImportError: No module named Image

解决办法：安装Python Imaging Library(PIL)

代码如下:

sudo easy_install PIL

— ZLIB (PNG/ZIP) support not available

— FREETYPE2 support not available

操作jpeg图片和png图片出现：

IOError: decoder jpeg not available 和 IOError: encoder zip not available

解决办法：
(1) 删除已经安装的PIL

代码如下:

sudo rm -rf /usr/local/lib/python2.6/site-packages/PIL-1.1.7-py2.6-linux-x86_64.egg/

代码如下:

sudo apt-get install libjpeg8 libjpeg62-dev libfreetype6 libfreetype6-dev
sudo ln -s /usr/lib/x86_64-linux-gnu/libjpeg.so /usr/lib/
sudo ln -s /usr/lib/x86_64-linux-gnu/libfreetype.so /usr/lib/
sudo ln -s /usr/lib/x86_64-linux-gnu/libz.so /usr/lib/

代码如下:

sudo easy_install PIL

— JPEG support available
— ZLIB (PNG/ZIP) support available
— FREETYPE2 support available

现在试试，已经ok了

希望本文所述对大家的Python程序设计有所帮助。