问题:

I want to install PIL package on windows, its easy. but decoder jpeg not available. which packages are needed to download and installed befor PIL so it gets work?

回答1:

I found the solution.

one has to use easy_install PIL instead of pip install PIP in Windows.
easy_install finds local installation or installs the libjpeg from the source and connects it to PIL while pip cannot do that.

回答2:

Solution that worked for me (assuming you have the tools to compile packages, which depend on your python version, installed):

Download precompiled binaries from http://gnuwin32.sourceforge.net/packages/jpeg.htm (you need the developer files and binaries).
Download PIL sources, open setup.py, and change JPEG_ROOT (line 37):
```
JPEG_ROOT = libinclude(JPEG_LIB_ROOT)
```
Run setup.py install.
Copy jpeg62.dll from the jpeglib binaries to your site-packages\PIL directory.

That's it, it should now work.