Python Image Library fails with message "decoder JPEG not available" - PIL

For those on OSX, I used the following binary to get libpng and libjpeg installed systemwide:

libpng & libjpeg for OSX

Because I already had PIL installed (via pip on a virtualenv), I ran:

pip uninstall PIL
pip install PIL --upgrade

This resolved the decoder JPEG not available error for me.

UPDATE (4/24/14):

Newer versions of pip require additional flags to download libraries (including PIL) from external sources. Try the following:

pip install PIL --allow-external PIL --allow-unverified PIL

See the following answer for additional info: pip install PIL dont install into virtualenv

UPDATE 2:

If on OSX Mavericks, you'll want to set the ARCHFLAGS flag as @RicardoGonzales comments below:

ARCHFLAGS=-Wno-error=unused-command-line-argument-hard-error-in-future pip install PIL --allow-external PIL --allow-unverified PIL

This is the only way that worked for me. Installing packages and reinstalling PIL didn't work.

On ubuntu, install the required package:

sudo apt-get install libjpeg-dev

(you may also want to install libfreetype6 libfreetype6-dev zlib1g-dev to enable other decoders).

Then replace PIL with pillow:

pip uninstall PIL
pip install pillow

libjpeg-dev is required to be able to process jpegs with pillow (or PIL), so you need to install it and then recompile pillow. It also seems that libjpeg8-dev is needed on Ubuntu 14.04

If you're still using PIL then you should really be using pillow these days though, so first pip uninstall PIL before following these instructions to switch, or if you have a good reason for sticking with PIL then replace "pillow" with "PIL" in the below).

On Ubuntu:

# install libjpeg-dev with apt
sudo apt-get install libjpeg-dev
# if you're on Ubuntu 14.04, also install this
sudo apt-get install libjpeg8-dev

# reinstall pillow
pip install --no-cache-dir -I pillow

If that doesn't work, try one of the below, depending on whether you are on 64bit or 32bit Ubuntu.

For Ubuntu x64:

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

Or for Ubuntu 32bit:

sudo ln -s /usr/lib/i386-linux-gnu/libjpeg.so /usr/lib/
sudo ln -s /usr/lib/i386-linux-gnu/libfreetype.so.6 /usr/lib/
sudo ln -s /usr/lib/i386-linux-gnu/libz.so /usr/lib/

Then reinstall pillow:

pip install --no-cache-dir -I pillow

(Edits to include feedback from comments. Thanks Charles Offenbacher for pointing out this differs for 32bit, and t-mart for suggesting use of --no-cache-dir).

The followed works on ubuntu 12.04:

pip uninstall PIL
apt-get install libjpeg-dev
apt-get install libfreetype6-dev
apt-get install zlib1g-dev
apt-get install libpng12-dev
pip install PIL --upgrade

when your see "-- JPEG support avaliable" that means it works.

But, if it still doesn't work when your edit your jpeg image, check the python path !! my python path missed /usr/local/lib/python2.7/dist-packages/PIL-1.1.7-py2.7-linux-x86_64.egg/, so I edit the ~/.bashrc add the following code to this file:

Edit: export PYTHONPATH=$PYTHONPATH:/usr/local/lib/python2.7/dist-packages/PIL-1.1.7-py2.7-linux-x86_64.egg/

then, finally, it works!!