今天在Python运行环境的服务器弄一个有关图像处理的程序时报这样的错：
1 | NameError: global name 'Image' is not defined |
import Image 了下，发现原来 Python 并没有自带图像处理库，需要独立安装……查了下，Python常用的图像处理库叫，可以使用 pip 安装，不错～于是在 用virtualenv 里敲入 pip install PIL。
安装很快完成，于是愉悦地刷新，等待程序的通过，结果又报错：
1 | IOError: decoder jpeg not available |
Google了下，发现通过 pip 安装的 PIL 不会安装 jpeg 的解码器……检查了下安装日志，也有这样的说明：
01 | -------------------------------------------------------------------- |
02 | PIL 1.1.7 SETUP SUMMARY |
03 | -------------------------------------------------------------------- |
04 | version 1.1.7 |
05 | platform linux2 2.7.5 (default, Sep 18 2013, 09:53:07) |
06 | [GCC 4.1.2 20080704 (Red Hat 4.1.2-54)] |
07 | -------------------------------------------------------------------- |
08 | *** TKINTER support not available |
09 | *** JPEG support not available |
10 | *** ZLIB (PNG/ZIP) support not available |
11 | *** FREETYPE2 support not available |
12 | *** LITTLECMS support not available |
13 | -------------------------------------------------------------------- |
14 | To add a missing option, make sure you have the required |
15 | library, and set the corresponding ROOT variable in the |
16 | setup.py script. |
JPEG support not available…… jpg都不支持，这是闹哪样……
于是只得手动安装了：
1 | wget http://effbot.org/downloads/Imaging-1.1.7.tar.gz |
2 | tar xvfz Imaging-1.1.7.tar.gz |
下载并解压成功之后，到解压目录，找到 Imaging-1.1.7/setup.py 这个文件，修改下面几行代码（默认TCL_ROOT的设置为NONE，这里要传到系统库的路径才行）：
1 | TCL_ROOT = "/usr/lib64/" |
2 | JPEG_ROOT = "/usr/lib64/" |
3 | ZLIB_ROOT = "/usr/lib64/" |
4 | TIFF_ROOT = "/usr/lib64/" |
5 | FREETYPE_ROOT = "/usr/lib64/" |
6 | LCMS_ROOT = "/usr/lib64/" |
再进行安装前的检查：
1 | python /root/nowamagic_venv/Imaging-1.1.7/setup.py build_ext -i |
检查没问题，可以执行安装了：
1 | python /root/nowamagic_venv/Imaging-1.1.7/setup.py install |
安装成功：
01 | -------------------------------------------------------------------- |
02 | PIL 1.1.7 SETUP SUMMARY |
03 | -------------------------------------------------------------------- |
04 | version 1.1.7 |
05 | platform linux2 2.7.5 (default, Sep 18 2013, 09:53:07) |
06 | [GCC 4.1.2 20080704 (Red Hat 4.1.2-54)] |
07 | -------------------------------------------------------------------- |
08 | *** TKINTER support not available |
09 | --- JPEG support available |
10 | --- ZLIB (PNG/ZIP) support available |
11 | --- FREETYPE2 support available |
12 | *** LITTLECMS support not available |
13 | -------------------------------------------------------------------- |
现在 jpg 已经被支持了，程序也执行成功，这里简单记录一下过程，方便后来者。顺便附带测试程序，用 Tornado 并生成缩略图：
01 | import time |
02 | import tempfile |
03 | import Image |
04 |
05 | class AsciiImageProcessHandler(tornado.web.RequestHandler): |
06 | def post(self): |
07 |
08 | if self.request.files: |
09 | for f in self.request.files['image']: |
10 | rawname = f['filename'] |
11 | dstname =str(int(time.time()))+'.'+rawname.split('.').pop() |
12 | thbname = "thumb_"+dstname |
13 |
14 | self.write( dstname ) |
15 |
16 | tf = tempfile.NamedTemporaryFile() |
17 | tf.write(f['body']) |
18 | tf.seek(0) |
19 |
20 | # create normal file |
21 | # img = Image.open(src) |
22 | img = Image.open(tf.name) |
23 | img.thumbnail((920,920),resample=1) |
24 | img.save("./static/upload/asciiimg/"+dstname) |
25 |
26 | # create thumb file |
27 | img.thumbnail((100,100),resample=1) |
28 | img.save("./static/upload/asciiimg_tn/"+thbname) |
29 | |
30 | tf.close() |