django-nginx-image 0.3

Resizing and cropping images via Nginx, and cache the result

Features:

• High-performance resize and crop via Nginx
• Transparent caching an images
• Template tag thumbnail for building correct URL for Nginx
• The Django command for convert unsupported images formats (example, BMP) to JPG

For more details see:

• http://github.com/adw0rd/django-nginx-image - the GitHub repository
• http://pypi.python.org/pypi/django-nginx-image - the PyPI page
• http://adw0rd.com/2012/django-nginx-image/ - article about this package on Russian
• http://adw0rd.com/2012/django-nginx-image/en/ - article about this package on English

Settings:

Add to settings.py:

INSTALLED_APPS = (
    'nginx_image',
)

Now, add two sections called server:

1. The cache server www.example.org, which will connect to the second server and receive changed image and save the result to the cache.
2. The image server image.example.org, which can to resize and to crop a images.

A sample of configuration file for your project:

http {

    proxy_cache_path <STORAGE_ROOT>/nginx/cache levels=1:2 keys_zone=<CACHE_NAME>:10m max_size=1G;

    server {
        listen 80;
        server_name www.example.org;

        location ~* ^/(resize|crop)/ {
            proxy_pass http://image.example.org$request_uri;
            proxy_cache <CACHE_NAME>;
            proxy_cache_key "$host$document_uri";
            proxy_cache_valid 200 1d;
            proxy_cache_valid any 1m;
            proxy_cache_use_stale error timeout invalid_header updating;
        }
    }

    server {
        listen 80;
        server_name image.example.org;

        location ~* ^/resize/([\d\-]+)/([\d\-]+)/(.+)$ {
            alias <STORAGE_ROOT>/$3;
            image_filter resize $1 $2;
            image_filter_buffer 2M;
            error_page 415 = /empty;
        }

        location ~* ^/crop/([\d\-]+)/([\d\-]+)/(.+)$ {
            alias <STORAGE_ROOT>/$3;
            image_filter crop $1 $2;
            image_filter_buffer 2M;
            error_page 415 = /empty;
        }

        location = /empty {
            empty_gif;
        }
    }
}

Where, STORAGE_ROOT is the path to directory with web-assests. For example I have in my settings.py:

STORAGE_ROOT = "/storage/kinsburg_tv"
MEDIA_ROOT = os.path.join(STORAGE_ROOT, "media")
STATIC_ROOT = os.path.join(STORAGE_ROOT, "static")

And "CACHE_NAME" is the arbitrarily name, example: "my_project_cache".

Usage:

In the templates can be used as follows:

{% load nginx_image %}

Proportionally resize a image, based on the width and the height:
    {% thumbnail user.profile.avatar 130 130 %}

Proportionally resize a image, based on the width:
    {% thumbnail user.profile.avatar 130 '-' %}
    {% thumbnail user.profile.avatar 130 0 %}
    {% thumbnail user.profile.avatar 130 %}

Proportionally resize a image, based on the height:
    {% thumbnail user.profile.avatar '-' 130 %}
    {% thumbnail user.profile.avatar 0 130 %}

Crop a image:
    {% thumbnail user.profile.avatar 130 130 crop=1 %}
    {% thumbnail user.profile.avatar 130 0 crop=1 %}
    {% thumbnail user.profile.avatar 0 130 crop=1 %}

Convert:

Unfortunaly, ngx_http_image_filter_module only supports JPEG, GIF and PNG, so you have to convert BMP to JPG:

./manage.py nginx_image_converter -i /storage/project/media -o /storage/project/newmedia

Available options:

-i SOURCE, --source=SOURCE
                    Source directory with pictures
-o DESTINATION, --destination=DESTINATION
                    Destination directory for save the pictures
-q QUALITY, --quality=QUALITY
                    Percentage of quality for images in JPG
-e, --change-extension
                    Change extension to "jpg"