Package: django-vimage
django-vimageDjango Image validation for theDjango Adminas a breeze.
Validations on: Size, Dimensions, Format and Aspect Ratio.Because, I love to look for the origin of a word/band/place/something,
this package name comes from the wordvalidateand (you guessed it)image. Thus,django-vimage. Nothing more, nothing less :)This package was created due to lack of similar Django packages that do
image validation. I searched for this but found nothing. So, I decided
to create a reusable Django package that will do image validation in a
simple manner. Just declare someImageFields and the rules to apply to
them in a simple Python dictionary. Firstly, I wrote the blueprint on a
piece of paper and then I, gradually, ported it to Django/Python code.DocumentationThe full documentation is athttps://django-vimage.readthedocs.io.QuickstartInstall django-vimage :pip install django-vimageAdd it to yourINSTALLED_APPS:INSTALLED_APPS = (
    ...
    'vimage.apps.VimageConfig',
    ...
)Finally, add theVIMAGEdict configuration somewhere in yoursettingsfile :VIMAGE = {
    'my_app.models': {
        'DIMENSIONS': (200, 200),
        'SIZE': {'lt': 100},
    }
}The aboveVIMAGEsetting sets the rules for all DjangoImageFieldfields under themy_appapp. More particular, allImageFields should be 200 x 200pxandless than 100KB. Any image
than violates any of the above rules, a nice-looking error message will
be shown (translated accordingly) in the Django admin page.A full example of possible key:value pairs is shown below. Note that the
following code block is not suitable for copy-paste into yoursettingsfile since it contains duplicate dict keys. It's just for demonstration.VIMAGE={# Possible keys are:# 'app.models'  # to all ImageFields inside this app# 'app.models.MyModel'  # to all ImageFields inside MyModel# 'app.models.MyModel.field'  # only to this ImageField# Example of applying validation rules to all images across# all models of myapp app'myapp.models':{# rules},# Example of applying validation rules to all images across# a specific model'myapp.models.MyModel':{# rules},# Example of applying validation rules to a# specific ImageField field'myapp.models.MyModel.img':{# rules},# RULES'myapp.models':{# By size (measured in KB)# Should equal to 100KB'SIZE':100,# defaults to eq (==)# (100KB <= image_size <= 200KB) AND not equal to 150KB'SIZE':{'gte':100,'lte':200,'ne':150,},# Custom error message'SIZE':{'gte':100,'lte':200,'err':'Your own error message instead of the default.''Supports <strong>html</strong> tags too!',},# By dimensions (measured in px)# Should equal to 1200x700px (width x height)'DIMENSIONS':(1200,700),# defaults to eq (==)# Should equal to one of these sizes 1000x300px or 1500x350px'DIMENSIONS':[(1000,300),(1500,350)],# Should be 1000x300 <= image_dimensions <= 2000x500px'DIMENSIONS':{'gte':(1000,300),'lte':(2000,500),},# width must be >= 30px and less than 60px# height must be less than 90px and not equal to 40px'DIMENSIONS':{'w':{'gt':30,'lt':60,},'h':{'lt':90,'ne':40,}},# By format (jpeg, png, tiff etc)# Uploaded image should be JPEG'FORMAT':'jpeg',# Uploaded image should be one of the following'FORMAT':['jpeg','png','gif'],# Uploaded image should not be a GIF'FORMAT':{'ne':'gif',},# Uploaded image should be neither a GIF nor a PNG'FORMAT':{'ne':['gif','png'],'err':'Wrong image <em>format</em>!'},}}FeaturesAn image may be validated against it's size (KB), dimensions (px),
format (jpeg, png etc) and aspect ratio (width/height ratio).Well formatted error messages. They have the form of:[IMAGE RULE_NAME]Validation error:image_valuedoes not meet validation rule:rule.Humanized error messages. All rules and image values arehumanized:'SIZE': {'gte': 100}becomesgreater than or equal to 100KBwhen rendered'DIMENSIONS': {'ne': (100, 100)}becomesnot equal to 100 x 100pxwhen renderedOverridable error messages. The default error messages may be overridden by defining anerrkey inside the validation rules:'SIZE': {'gte': 100, 'err': 'Custom error'}becomesCustom errorwhen renderedHTML-safe (custom) error messages. All error messages (the default or your own) are passed through the functionmark_safe.Cascading validation rules. It's possible to define a generic rule
to someImageFieldfields of an app and then define another set of
rules to a specificImageFieldfield. Common rules will override
the generic ones and any new rules will be added to the specificImageFieldfield:myapp.models: {
    'SIZE': {
        'lt': 120,
    },
    'FORMAT': 'jpeg',
    'DIMENSIONS': {
        'lt': (500, 600),
    }
 },
 myapp.models.MyModel.img: {
    'DIMENSIONS': (1000, 500),
 },In the example above (the order does not matter), allImageFields
should beless than 120KB,JPEGimagesandless than 500 x 600px.
However, themyapp.models.MyModel.imgfield should beless than 120KB,JPEGimageandequal to 1000 x 500px.Running TestsDoes the code actually work?source <YOURVIRTUALENV>/bin/activate
(myenv) $ pip install tox
(myenv) $ toxFuture additionsValidation of image mode (whether the uploaded image is in indexed
mode, greyscale mode etc) based onimage's mode.
This is quite easy to implement but rather ararevalidation
requirement. Thus, it'll be implemented if users want to validate
the mode of the image (which again, it's rare for the web).If you think of any other validation (apart from svg) that may be
applied to an image and it's not included in this package, please
feel free to submit an issue or a PR.CreditsTools used in rendering this package:Cookiecuttercookiecutter-djangopackage