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https://github.com/jonasundderwolf/django-image-cropping

Django helper application to easily and non-destructively crop arbitrarily large images in admin and frontend.
https://github.com/jonasundderwolf/django-image-cropping

django feincms image-cropping python

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Django helper application to easily and non-destructively crop arbitrarily large images in admin and frontend.

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README 

        
=====================

django-image-cropping

=====================



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django-image-cropping is an app for cropping uploaded images via Django's admin backend using `Jcrop

`_.



Screenshot:



.. image:: docs/django_image_cropping_example.png

    :alt: Screenshot of the cropping



django-image-cropping is perfect when you need images with a specific size for your templates but want your

users or editors to upload images of any dimension. It presents a selection with a fixed aspect ratio so your users

can't break the layout with oddly-sized images.



The original images are kept intact and only get cropped when they are displayed.

Large images are presented in a small format, so even very big images can easily be cropped.



The necessary fields, widgets and a template tag for displaying the

cropped image in your templates are provided.



Also works with `FeinCMS `_ content types!



Installation

============



#. Install django-image-cropping using ``pip``::



    pip install django-image-cropping



By default ``django-image-cropping`` ships with an ``easy-thumbnails``-backend which requires ``easy-thumbnails`` to also be installed

and added to the ``INSTALLED_APPS``.



The `easy-thumbnails` backend requires that you adjust the thumbnail processors in your ``settings``::



    INSTALLED_APPS = [

        ...

        'easy_thumbnails',

        'image_cropping',

    ]



    from easy_thumbnails.conf import Settings as thumbnail_settings

    THUMBNAIL_PROCESSORS = (

        'image_cropping.thumbnail_processors.crop_corners',

    ) + thumbnail_settings.THUMBNAIL_PROCESSORS



Configuration

=============



Add an ``ImageRatioField`` to the model that contains the ``ImageField`` for the images you want to crop.



The ``ImageRatioField`` simply stores the boundaries of the cropped image.

It expects the name of the associated ``ImageField`` and the desired size of the cropped image as arguments.



The size is passed in as a string and defines the aspect ratio of the selection *as well* as the minimum

size for the final image::



    from django.db import models

    from image_cropping import ImageRatioField



    class MyModel(models.Model):

        image = models.ImageField(blank=True, upload_to='uploaded_images')

        # size is "width x height"

        cropping = ImageRatioField('image', '430x360')



You can configure a `size warning`_ if users try to crop a selection smaller than the defined minimum.



Admin Integration

=================



Add the ``ImageCroppingMixin`` to your ``ModelAdmin``::



    from django.contrib import admin

    from image_cropping import ImageCroppingMixin



    class MyModelAdmin(ImageCroppingMixin, admin.ModelAdmin):

        pass



    admin.site.register(MyModel, MyModelAdmin)



If your setup is correct you should now see the enhanced image widget that provides a selection

area.



Backends

========



django-image-cropping delegates the cropped image generation to a backend.



A backend based on `easy-thumbnails` is provided, but it's possible to use a custom backend.

The ``IMAGE_CROPPING_BACKEND`` setting expects a dotted path to a class that implements the required methods.

You can omit this setting if you want to use the default backend.



In case you use a custom backend you can provide an optional dict that will be used to populate the backend's

constructor params.



Default settings::



    IMAGE_CROPPING_BACKEND = 'image_cropping.backends.easy_thumbs.EasyThumbnailsBackend'

    IMAGE_CROPPING_BACKEND_PARAMS = {}



Frontend

========



django-image-cropping provides a templatetag for displaying a cropped thumbnail.

Any other processor parameter (like ``bw=True`` or ``upscale=True``) will be forwarded to the backend::



    {% cropped_thumbnail yourmodelinstance "ratiofieldname" [scale=INT|width=INT|height=INT|max_size="INTxINT"] %}



Example usage::



    {% load cropping %}

    



Or generate the URL from Python code in your view::



    from image_cropping.utils import get_backend

    thumbnail_url = get_backend().get_thumbnail_url(

        yourmodel.image,

        {

            'size': (430, 360),

            'box': yourmodel.cropping,

            'crop': True,

            'detail': True,

        }

    )



easy_thumbnails

---------------



You can also use the standard ``easy-thumbnails`` templatetag with the ``box`` parameter::



    {% load thumbnail %}

    {% thumbnail yourmodel.image 430x360 box=yourmodel.cropping crop detail %}



Or generate the URL from Python code in your view::



    from easy_thumbnails.files import get_thumbnailer

    thumbnail_url = get_thumbnailer(yourmodel.image).get_thumbnail({

        'size': (430, 360),

        'box': yourmodel.cropping,

        'crop': True,

        'detail': True,

    }).url



ModelForm

=========



If you want to use the cropping widget outside the admin, you'll need to define the ``ImageField`` as

an ``ImageCropField``::



    from django.db import models

    from image_cropping import ImageCropField, ImageRatioField



    class MyModel(models.Model):

        image = ImageCropField(blank=True, upload_to='uploaded_images')

        # size is "width x height"

        cropping = ImageRatioField('image', '430x360')



Alternatively, override the widget in your ModelForm (you just need to do one of these two, not both!)::



    from django import forms

    from image_cropping import ImageCropWidget



    class MyModelForm(forms.ModelForm):

        class Meta:

            widgets = {

                'image': ImageCropWidget,

            }



Remember to include the form media in the ```` of your HTML::



    

      

        {{ form.media }}

      

      

        {{ form }}

      

    



The cropping itself happens in the ``ImageRatioField``, the ``ImageCropField`` will still behave like a regular ``ImageField``.



If you're selectively including or excluding fields from the ModelForm, remember to include the ``ImageRatioField``.



Multiple formats

================



If you need the same image in multiple formats, simply specify another ``ImageRatioField``.

This will allow the image to be cropped twice::



    from image_cropping import ImageRatioField, ImageCropField



    image = ImageCropField(blank=True, upload_to='uploaded_images')

    # size is "width x height"

    list_page_cropping = ImageRatioField('image', '200x100')

    detail_page_cropping = ImageRatioField('image', '430x360')



In your templates, use the corresponding ratio field::



    {% load cropping %}

    {% cropped_thumbnail yourmodel "list_page_cropping" %}



Foreign Keys

============



If you need to crop an image contained within another model, referenced by a ForeignKey, the ``ImageRatioField`` is

composed of the ``ForeignKey`` name, a double underscore, and the ``ImageField`` name::



    from django.db import models

    from image_cropping.fields import ImageRatioField



    class Image(models.Model):

        image_field = models.ImageField(upload_to='image/')



    class NewsItem(models.Model):

        title = models.CharField(max_length=255)

        image = models.ForeignKey(Image)

        cropping = ImageRatioField('image__image_field', '120x100')



Cropping foreign keys only works in the admin for now, as it reuses the ``raw_id`` widget.



.. _free cropping:



Free cropping

=============



If you do not need a *fixed* ratio, you can disable this constraint by setting ``free_crop`` to ``True``.

In this case the size parameter is the desired minimum and is also used for the size-warning::



    from image_cropping import ImageRatioField, ImageCropField



    image = ImageCropField(blank=True, upload_to='uploaded_images')



    # size is "width x height" so a minimum size of 200px x 100px would look like this:

    min_free_cropping = ImageRatioField('image', '200x100', free_crop=True)



Use the ``max_size`` parameter of the templatetag if you want to limit the display size of a thumbnail::



     



Disabling cropping

==================



If you want cropping to be optional, use ``allow_fullsize=True`` as an additional keyword argument for your ``ImageRatioField``.



Editors can now switch off cropping by unchecking a checkbox next to the image cropping widget::



     image_with_optional_cropping = ImageRatioField('image', '200x100', allow_fullsize=True)



Settings

========



Thumbnail size

--------------



You can define the maximum size of the admin preview thumbnail in your ``settings``::



    # size is "width x height"

    IMAGE_CROPPING_THUMB_SIZE = (300, 300)



.. _size warning:



Size warning

------------



You can warn users about crop selections that are smaller than the size defined in the ``ImageRatioField``.

When users try to do a smaller selection, a red border appears around the image.



To use this functionality for a single image add the ``size_warning`` parameter to the ``ImageRatioField``::



    cropping = ImageRatioField('image', '430x360', size_warning=True)



You can enable this functionality project-wide by adding the following line to your ``settings``::



    IMAGE_CROPPING_SIZE_WARNING = True



Custom jQuery

-------------



By default the image cropping widget uses the jQuery version vendored with the Django admin.



You can point to another version using the ``IMAGE_CROPPING_JQUERY_URL`` setting, though compatibility

issues may arise if your jQuery version differs from the one that is tested against.



You can also set ``IMAGE_CROPPING_JQUERY_URL`` to ``None`` to disable inclusion of jQuery by the widget.

You are now responsible for including ``jQuery`` yourself, both in the frontend and in the admin interface.



Custom backend

--------------



You can define a custom backend::



    IMAGE_CROPPING_BACKEND = 'image_cropping.backends.easy_thumbs.EasyThumbnailsBackend'



You can provide an optional dict that will be used to populate the backend's

constructor::



    IMAGE_CROPPING_BACKEND_PARAMS = {'version_suffix': 'thumb'}



See the built-in backends on Backends_.



Testing

=======



- Setup a virtualenv with one of the supported versions of Python

- Install the example project: ``pip install -r example/requirements.txt``

- Run ``pytest``

- In case you want to test against multiple Python versions install and run ``tox``



Troubleshooting

===============



The cropping widget is not displayed when using a ``ForeignKey``.

    Make sure you do **not** add the corresponding image field to ``raw_id_fields``.



Changelog

=========



1.7

---



- Add support for Django 4.0 (`@jwedel `_ in `#176 `_)



1.6.2

-----



- Use the jQuery bundled with Django as the default jQuery for image cropping



1.6.1

-----



- Add default setting for jquery url to app conf



1.6

---



- Add support for Django 3.2

- Add support for Python 3.9



1.5

---



- Drop support for Python 3.5 (although it should still work)

- Add support for Django 3.1

- Minified JS and reduce potential for incompatibility with other django libraries (See #148)

- Fix formfield_for_dbfield signature (#134)

- Fix CSS property word separator (#131)

- Enforce isort in tests



1.4

---



- Removed more old code

- Move testing and packaging to GitHub Actions



1.3

---



- Add support for Django 3.0

- Drop support for Python < 3.5

- Drop support for Django < 2.2



1.2

---



- Add support for Django 2.1



1.1

---



- Make django-image-cropping compatible with Django 1.11



1.0.4

-----



- Move and encapsulate the logic for creating cropped thumbnails to a swappable backend. (`@fgmacedo `_ in #92)



1.0

---



"If your software is being used in production, it should probably already be 1.0.0." (http://semver.org)



0.9

---



This release addresses mainly the test coverage and internal stuff.



Noteable (breaking) changes and things to be considered when upgrading from an older version:



- `django-appconf `_ is now used for handling defaults and settings.



  * **Breaking Change**: JQUERY_URL changed to IMAGE_CROPPING_JQUERY_URL as part of this transition.



- The ``cropped_thumbnail`` tag is now based on Django's ``simple tag``.



  * **Breaking Change**: Arguments for the the tag now need to be put in quotes.

  * If you are still using Django 1.4 remember that `you can't easily use `_ ``True`` or ``False`` as template tag arguments.



- Any processor parameter (like bw=True or upscale=True) can be used in the ``cropped_thumbnail`` tag.



- Moved inline css to a dedicated ``image_cropping.css`` style sheet



0.8

---



- **Minimum** requirements changed to **Django 1.4** and **easy-thumbnails 1.4**

- Added Python 3 compatibility. Python 2.6 is now the minimum required Python version.

- Added a `free cropping`_ option, so cropping is no longer restricted to fixed ratios.

- Removed the deprecated ``CropForeignKey`` field.



0.7

---



- Made the widget for the ``ImageCropField`` overwritable to allow custom widgets. (Remember to use the ``ImageCroppingMixin`` in the admin as the image cropping widgets are no longer implicitly set.)

- Updated ``Jcrop`` and ``jQuery`` dependencies.

- Moved docs to *Read the Docs*: https://django-image-cropping.readthedocs.org