I am new to GIS technology. I have configured a map server OSGEO4W. I am able to render maps using WMS and openlayers. But the rendering is very slow.

For faster rendering I want to use Mapproxy. I have installed Mapproxy with Python virtual environment. Mapproxy service is running fine. I am checking it with the following url "http://"mylocalhost":8080/" Then, it is showing:

"Welcome to MapProxy 1.5.0"

I have changed the mapproxy.yaml as per the demo application file so that it shows its "demo" application. When I am browsing demo application and rendering map using EPSG:4326 or EPSG:900913 (even when I am using it in my application with openlayers and map file, then also it is showing the the following):

It is showing a blank image. It is showing the following error on command window:

File "c:\mapproxy_venv\lib\site-packages\pil-1.1.7-pu2.7-win-amd64.egg\Image.py" line 385, in _getdecoder raise IOError("decoder %s not available" % decoder_names) IOError: decoder zip not available

It means it does not receive "decoder zip".

Please help me to fix this problem.


  • I will need to see your YAML file in order to help debug this. Would you mind posting? EDIT: From the error, it looks like you are getting a PIL error, not necessarily a MapProxy error. How did you install PIL? Did you use PIP (within your virtualenv) to install it?
    – Trann
    Commented Feb 6, 2013 at 21:38

1 Answer 1


Same issue here.

Mapproxy on Windows 7 64-bit. I installed it following the docs: http://mapproxy.org/docs/nightly/install_windows.html

I had to compile PIL, as a binary version was not available for my system. I experienced issues with vcvarsall.bat, but in the end I managed to compile it using the free Windows SDK C/C++ compiler from Microsoft, as explained here: https://github.com/cython/cython/wiki/64BitCythonExtensionsOnWindows

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