app/django/core/files/images.py
author Madhusudan C.S. <madhusudancs@gmail.com>
Sat, 06 Jun 2009 17:28:56 +0200
changeset 2401 bf70c5a0ef66
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Added logic for every GHOP specific model. Defined logic for every model defined for GHOP. These logics do nothing special now. They are just inherited from their parent classes. Necessary GHOP specific logic will be added later as necessary. Reviewed by: Lennard de Rijk

"""
Utility functions for handling images.

Requires PIL, as you might imagine.
"""

from django.core.files import File

class ImageFile(File):
    """
    A mixin for use alongside django.core.files.base.File, which provides
    additional features for dealing with images.
    """
    def _get_width(self):
        return self._get_image_dimensions()[0]
    width = property(_get_width)

    def _get_height(self):
        return self._get_image_dimensions()[1]
    height = property(_get_height)

    def _get_image_dimensions(self):
        if not hasattr(self, '_dimensions_cache'):
            self._dimensions_cache = get_image_dimensions(self)
        return self._dimensions_cache

def get_image_dimensions(file_or_path):
    """Returns the (width, height) of an image, given an open file or a path."""
    from PIL import ImageFile as PILImageFile
    p = PILImageFile.Parser()
    if hasattr(file_or_path, 'read'):
        file = file_or_path
    else:
        file = open(file_or_path, 'rb')
    while 1:
        data = file.read(1024)
        if not data:
            break
        p.feed(data)
        if p.image:
            return p.image.size
    return None