django-tint 0.0.4

Transparent image transformation system

Usage

You must define your transformation in your TINT_TRANSFORMATIONS settings variable.

You set your images on your models puting a ForeignKey to tint.models.Image.

Then you put your images in your templates using the at_transformation filter. Example:

{% load tint %}

<img src="{{ mymodel.my_image_field|at_transformation:"my-transformation-definition" }}" />

If you use django-jinja you only have to use the image_at_transformation function. Example:

<img src="{{ image_at_transformation(mymodel.my_image_field, "my-transformation-definition") }}" />

Default ImageProc Actions

Django-tint default Image Processor comes with some actions, here you have the list:

Action	Description	Params
crop	Crop an image to a width and height.	height, width, align, valign
scale	Scale an image to a width and height (deforming it).	height, width
fit	Scale an image to a width and height and crop the overflow.	height, width, align, valign
watermark	Paste a watermark on a image.	watermark_image, opacity
grayscale	Convert the image to grayscale.
flip	Flip the image vertically.
mirror	Flip the image horizontally.
equalize	Equalize the image histogram.
autocontrast	Maximize (normalize) image contrast.	cutoff
invert	Invert the image colors.

Configuration

In Django-tint you can define your ImageProc class (normally will be a subclass of the DefaultImageProc) to add your own image transformations. You can use it configuring the TINT_IMAGE_PROCESSOR settings variable. Example:

TINT_IMAGE_PROCESSOR = 'myapp.my_image_processor_module.MyImageProcessorClass'

If the variable is not defined the DefaultImageProc is used.

Then you can configure your transformations as a dictionary. The name of the transformation is the key, and the value is a list of “actions”. An action is a dictionary with one key ‘action’ with the name of the action, and the other keys the parameters to use in this action. Example:

TINT_TRANSFORMATIONS = {
  'example1': [
      {
          "action": 'fit',
          "width": 1024,
          "height": 768,
          "align": 'center',
          "valign": 'middle',
      },
      {
          "action": 'watermark',
          "image": 'example.watermark.png',
          "opacity": 0.5,
      },
  ],
  'example2': [
      {
          "action": 'fit',
          "width": 800,
          "height": 600,
          "align": 'center',
          "valign": 'middle',
      },
      {
          "action": 'watermark',
          "image": 'example.watermark.png',
          "opacity": 0.5,
      },
  ]
}