Pillow and JPEG2000: decoder jpeg2k not available

Question

I'm trying to set up Flask-IIIF to work with jp2-files, or JPEG2000. Right out of the box I get an error from the Pillow library: IOError: decoder jpeg2k not available

I've tried googling it, and one StackOverflow post told me to make sure libjpeg-dev and libjpeg8-dev are installed and up to date, but they were already installed. After making sure they were there, I did try to reinstall pillow without cache: pip install --no-cache-dir -I pillow

The environment is Docker, based on a 15.10 Ubuntu image. Python version is 2.7.10. Pillow version from pip freeze is 4.1.1

edit: I also tried the other suggestion of Python Image Library fails with message "decoder JPEG not available" - PIL:

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

Answer 1

for linux

sudo yum install -y libjpeg-devel
sudo pip uninstall pillow
sudo pip install pillow

for windows

# download
import imageio
imageio.plugins.freeimage.download()

# install
pip uninstall pillow
pip install pillow

Answer 2

Pillow needs the OpenJPEG library to decode JPEG2000 files. libjpeg only deals with regular JPEGs.

See the note in the Pillow docs at the end of this section: http://pillow.readthedocs.io/en/latest/handbook/image-file-formats.html#jpeg-2000

Answer 3

Windows users: After you installed OpenJPEG and added its bin folder to PATH, you need to re-build the pillow library. Using Conda I didn't find a solution to do that so I ended up using the windows installer from PyPi as suggested in this answer here. The installer found my Anaconda installation and it seems it simply overwrote the pillow library there.