Template Tags


The easiest way to use Daguerre is through the {% adjust %} template tag:

{% load daguerre %}
<img src="{% adjust my_model.image 'fill' width=128 height=256 %}" />

The {% adjust %} tag works directly with any ImageField (or storage path). There is no magic. You don’t need to change your models. It Just Works.

Daguerre provides a number of built-in adjustments (such as ‘fill’) which can be used with the {% adjust %} out of the box, as well as an API for registering custom adjustments.

Take this picture:


Full size: 800x600. This photograph, by Wikipedia user Sloesch, is licensed as CC BY-SA.

Let’s use {% adjust %} with width 200 (25%) and height 300 (50%), with three of the built-in adjustments.

“fit” “fill” “crop”
../_images/cat_fit.jpg ../_images/cat_fill.jpg ../_images/cat_crop.jpg
Fits the entire image into the given dimensions without distorting it. Fills the entire space given by the dimensions by cropping to the same width/height ratio and then scaling down or up. Crops the image to the given dimensions without any resizing.

Chaining Adjustments

You can also use the {% adjust %} tag to chain multiple adjustments. Take the following:

{% load daguerre %}
{% adjust my_model.image 'ratiocrop' ratio='16:9' 'fit' width=200 %}

This tag first crops the image to a 16:9 ratio, then scales as much as needed to fit within a 200-pixel width. In other words:


See also

daguerre.adjustments for more built-in adjustments.

Getting adjusted width and height

{% load daguerre %}
{% adjust my_model.image 'fit' width=128 height=128 as image %}
<img src="{{ image }}" width="{{ image.width }}" height="{{ image.height }}" />

The object being set to the image context variable is an AdjustmentInfoDict instance. In addition to rendering as the URL for an image, this object provides access to some other useful pieces of information—in particular, the width and height that the adjusted image will have, based on the width and height of the original image and the parameters given to the tag. This can help you avoid changes to page flow as adjusted images load.

Let’s be lazy

So the {% adjust %} tag renders as a URL to adjusted image, right? Yes, but as lazily as possible. If the adjustment has already been performed, the adjusted image’s URL is fetched from the database. If the adjustment has not been performed, the tag renders as a URL to a view which, when accessed, will create an adjusted version of the image and return a redirect to the adjusted image’s actual URL.

This does have the downside of requiring an additional request/response cycle when unadjusted images are fetched by the user – but it has the upside that no matter how many {% adjust %} tags you have on a page, the initial load of the page won’t be slowed down by (potentially numerous, potentially expensive) image adjustments.


The adjustment view has some light security in place to make sure that users can’t run arbitrary image resizes on your servers.


If you are using a large number of similar adjustments in one template - say, looping over a queryset and adjusting the same attribute each time - you can save yourself queries by using {% adjust_bulk %}.

{% load daguerre %}
{% adjust_bulk my_queryset "method.image" "fill" width=200 height=400 as adjusted_list %}
{% for my_model, image in adjusted_list %}
  <img src="{{ image }}" />
{% endfor %}

The syntax is similar to {% adjust %}, except that:

  • as <varname> is required.
  • an iterable (my_queryset) and a lookup to be performed on each item in the iterable ("method.image") are provided in place of an image file or storage path. (If the iterable is an iterable of image files or storage paths, the lookup is not required.)

You’ve got everything you need now to use Daguerre and resize images like a champ. But what if you need more control over how your images are cropped? Read on to learn about Smart Cropping with Areas.