django-url-imaging

django-url-imaging provides URL-based image processing functionality for Django projects. It features a plugabble storage system with implementations for storing images locally, on Amazon S3 or using the SCP utiltiy to copy them to another server.

Overview

Once installed and configured, django-url-imaging will allow you to embed thumbnails and other image transformations using nothing more than a specially crafted URL. As an example, if you configured django-url-imaging to listen for requests on /thumbnails/ and needed to have a resized copy of the image at http://media.mydomain.com/foo.jpg, you would just create a link like:

<img src="/thumbnails/resize/50x50/media.mydomain.com/foo.jpg" />

django-url-imaging provides many different URL-based commands for image processing such as cropping, resizing, scaling, watermarking and much more. For more information on django-url-imaging, please check out the Wiki.

Installation

1. Download and install django-url-imaging using Distutils:

$ sudo python setup.py install

2. Add the urlimaging app to INSTALLED_APPS
3. Include urlimaging.urls as a resource in your urls.py:

(r'thumbnails/', include('urlimaging.urls')),

4. Finally, depending on if you want to use S3 or local file storage, configure the appropriate settings:

Configuration

Depending on how you plan to store your images, you will need to add one of the following sets of properties to your settings.py file:

Amazon S3

• IMAGE_STORAGE_BACKEND – This should be set to 'S3ImageStorage' to specify the S3 storage backend.
• S3_BUCKET_NAME – The name of the bucket (which should already be created) on S3 where images will be stored.
• S3_EXPIRES (optional) – The length of time which the S3-generated URL will be valid.
• AWS_ACCESS_KEY_ID – The AWS access key provided by Amazon.
• AWS_SECRET_ACCESS_KEY – The AWS secret access key provided by Amazon.

Local Image Storage

• IMAGE_STORAGE_BACKEND – This parameter should be set to 'LocalImageStorage' for the local image storage backend.

• IMAGE_STORAGE_DIR (optional) – The full path to the directory where images should be stored if this is not set, the value is inherited from MEDIA_ROOT. This directory should be publicly accessible since the application doesn't serve images directly from it.

• IMAGE_WHITELIST_FN – Should be defined as a function that takes one parameter of the URL and returns a boolean. The function should return False for urls that shouldn't be processed. In most cases, you might want to use something similar to

  IMAGE_WHITELIST_FN = lambda url: True

SCP

If you'd like to use the scp command to copy the generated files to another UNIX-like server, configure the following options:

• PROCESSED_MEDIA_URL - A URL where the images can be accessed once they are stored
• SSH_MEDIA_USER - The username which has ssh access on the remote host
• SSH_MEDIA_PATH - The path to where the images will be stored on the remote host
• SSH_IDENTITY_FILE - If an identity file is required for access to the remote host, this is the path to that file.

Additional Configuration

• MEDIA_URL – If you're using the LocalImageStorage backend, setting this parameter gives the root url that serves images stored in the IMAGE_STORAGE_DIR
• FONT_PATH - The path to the font file to be used when using the watermark operation. Defaults to /usr/share/fonts/truetype/freefont/FreeSansBold.ttf