When uploading an image with Django admin, or a Django based CMS, you receive the following error:
Upload a valid image. The file you uploaded was either not an image or a corrupted image.
The solution, on CentOS, Red Hat and Fedora, is to ensure that Python Image Library (PIL) is installed and compiled after libjpeg-devel is installed:
sudo yum install libjpeg-devel workon mysite pip uninstall PIL pip install PIL
This will compile PIL with the correct JPG support and fix the error above.