Easy Thumbnails
A powerful, yet easy to implement thumbnailing application for Django 4.2+
Below is a quick summary of usage. For more comprehensive information,
view the full
documentation
online or the peruse the project\'s docs
directory.
Breaking News
Version 2.8.0 adds support for thumbnailing SVG images when installed
with the [svg]
extra.
Of course it doesn\'t make sense to thumbnail SVG images, because being in vector format they can scale to any size without quality of loss. However, users of easy-thumbnails may want to upload and use SVG images just as if they would be PNG, GIF or JPEG. They don\'t necessarily care about the format and definitely don\'t want to convert them to a pixel based format. What they want is to reuse their templates with the templatetag thumbnail and scale and crop the images to whatever their [\<img src=\"...\" width=\"...\" height=\"...\">]{.title-ref} has been prepared for.
This is done by adding an emulation layer named VIL, which aims to be compatible with the PIL library. All thumbnailing operations, such as scaling and cropping behave like pixel based images. The final filesize of such thumbnailed SVG images doesn\'t of course change, but their width/height and bounding box may be adjusted to reflect the desired size of the thumbnailed image.
::: note ::: title Note :::
This feature is new and experimental, hence feedback about its proper functioning in third parts applications is highly appreciated. :::
Installation
Run pip install easy-thumbnails
.
Add easy_thumbnails
to your INSTALLED_APPS
setting:
INSTALLED_APPS = (
...
'easy_thumbnails',
)
Run manage.py migrate easy_thumbnails
.
Example usage
Thumbnail options can be predefined in settings.THUMBNAIL_ALIASES
or
just specified in the template or Python code when run.
Using a predefined alias
Given the following setting:
THUMBNAIL_ALIASES = {
'': {
'avatar': {'size': (50, 50), 'crop': True},
},
}
Template:
{% load thumbnail %}
<img src="{{ profile.photo|thumbnail_url:'avatar' }}" alt="" />
Python:
from easy_thumbnails.files import get_thumbnailer
thumb_url = get_thumbnailer(profile.photo)['avatar'].url
Manually specifying size / options
Template:
{% load thumbnail %}
<img src="{% thumbnail profile.photo 50x50 crop %}" alt="" />
Python:
from easy_thumbnails.files import get_thumbnailer
options = {'size': (100, 100), 'crop': True}
thumb_url = get_thumbnailer(profile.photo).get_thumbnail(options).url
Using in combination with other thumbnailers
Alternatively, you load the templatetags by {% load easy_thumbnails_tags %} instead of traditional {% load thumbnail %}. It\'s especially useful in projects that do make use of multiple thumbnailer libraries that use the same name ([thumbnail]{.title-ref}) for the templatetag module:
{% load easy_thumbnails_tags %}
<img src="{% thumbnail profile.photo 50x50 crop %}" alt="" />
Fields
You can use ThumbnailerImageField
(or ThumbnailerField
) for easier
access to retrieve or generate thumbnail images.
For example:
from easy_thumbnails.fields import ThumbnailerImageField
class Profile(models.Model):
user = models.OneToOneField('auth.User')
photo = ThumbnailerImageField(upload_to='photos', blank=True)
Accessing the field\'s predefined alias in a template:
{% load thumbnail %}
<img src="{{ profile.photo.avatar.url }}" alt="" />
Accessing the field\'s predefined alias in Python code:
thumb_url = profile.photo['avatar'].url
Thumbnail options
crop
Before scaling the image down to fit within the size
bounds, it first
cuts the edges of the image to match the requested aspect ratio.
Use crop="smart"
to try to keep the most interesting part of the
image,
Use crop="0,10"
to crop from the left edge and a 10% offset from the
top edge. Crop from a single edge by leaving dimension empty (e.g.
crop=",0"
). Offset from the right / bottom by using negative numbers
(e.g., crop=\"-0,-10\").
Often used with the upscale
option, which will allow enlarging of the
image during scaling.
quality=XX
Changes the quality of the output JPEG thumbnail. Defaults to 85
.
In Python code, this is given as a separate option to the
get_thumbnail
method rather than just alter the other.
keep_icc_profile
If [True]{.title-ref}, when saving a thumbnail with the alias that defines this option, the ICC profile of the image will be preserved in the thumbnail, if present in the first place.
Other options
Valid thumbnail options are determined by the \"thumbnail processors\" installed.
See the reference documentation for a complete list of options provided by the default thumbnail processors.