This is a my fork of original module django-thumbs, which was created by Antonio Melé(see http://django.es) and maintained till Jun 08 2009(latest commit date). Great thanks to Antotio!

The easiest way to create thumbnails for your images with Django. Works with any StorageBackend.

Features

1. Easy to integrate in your code (no database changes, works as an ImageField)
2. Works perfectly with any StorageBackend
3. Generates thumbnails after image is uploaded into memory
4. Deletes thumbnails when the image file is deleted
5. Provides easy access to the thumbnails' URLs (similar method as with ImageField)

django-thumb2 requires django >1.1. Perfectly works on 1.2.

Installation

1. Download thumbs.py
2. Import it in your models.py and replace ImageField with ImageWithThumbsField in your model
3. Add a sizes attribute with a list of sizes you want to use for the thumbnails
4. Make sure your have defined MEDIA_URL in your settings.py
5. That's it!

Working example

models.py

from django.db import models
from thumbs import ImageWithThumbsField

class Person(models.Model):
    photo = ImageWithThumbsField(upload_to='images', sizes=((125,125),(200,200)))
    second_photo = ImageWithThumbsField(upload_to='images')

In this example we have a Person model with 2 image fields.

You can see the field second_photo doesn't have a sizes attribute. This field works exactly the same way as a normal ImageField.

The field photo has a sizes attribute specifying desired sizes for the thumbnails. This field works the same way as ImageField but it also creates the desired thumbnails when uploading a new file and deletes the thumbnails when deleting the file.

With ImageField you retrieve the URL for the image with: someone.photo.url With ImageWithThumbsField you retrieve it the same way. You also retrieve the URL for every thumbnail specifying its size: In this example we use someone.photo.url_125x125 and someone.photo.url_200x200 to get the URL of both thumbnails.

Uninstall

At any time you can go back and use ImageField again without altering the database or anything else. Just replace ImageWithThumbsField with ImageField again and make sure you delete the sizes attribute. Everything will work the same way it worked before using django-thumbs. Just remember to delete generated thumbnails in the case you don't want to have them anymore.

Inner logic: resizing.

Quad thumbs(if you requested NxN size of thumbnail)

Unknown, lol. I need to review this module more time, but not now, sorry :C

Unquad thumbs(if you requested NxJ size)

There is difference beyond original module, but i think it is more sensible. It resizes image by minimal side. If you need 100x50 thumb, but image was 300x500, images resizes into 200x50. Next step - cropping. It crops image to needed thumbnail size, making it centered.

Original logic keeps in the PIL, because django-thumb just calls PIL.thumbnail with needed size as argument. So, it just fits image into needed size, what makes whitespace in the bottom or right size of image. No! It doesn't makes whitespaces, it just crops all canvas, not a layer! So, if you'll try to use PIL.thumbnail as it is by 300x500 image and 200x50 thumb size, you'll get an 30x50 image.

Dont believe me? Just check it:

>>> img = Image.open("check.png")
>>> img
<PIL.PngImagePlugin.PngImageFile image mode=RGB size=300x500 at 0x7F906D696B90>
>>> img.size
(300, 500)
>>> img.thumbnail((200, 50), Image.ANTIALIAS)
>>> img
<PIL.PngImagePlugin.PngImageFile image mode=RGB size=30x50 at 0x7F906D696B90>
>>> img.size
(30, 50)

This is no sense, isn't? Thats why i've reworked this myself.