Source code for django.core.files.images

"""
Utility functions for handling images.

Requires Pillow as you might imagine.
"""
import zlib

from django.core.files import File


[docs]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'): close = self.closed self.open() self._dimensions_cache = get_image_dimensions(self, close=close) return self._dimensions_cache
def get_image_dimensions(file_or_path, close=False): """ Returns the (width, height) of an image, given an open file or a path. Set 'close' to True to close the file at the end if it is initially in an open state. """ from PIL import ImageFile as PillowImageFile p = PillowImageFile.Parser() if hasattr(file_or_path, 'read'): file = file_or_path file_pos = file.tell() file.seek(0) else: file = open(file_or_path, 'rb') close = True try: # Most of the time Pillow only needs a small chunk to parse the image # and get the dimensions, but with some TIFF files Pillow needs to # parse the whole file. chunk_size = 1024 while 1: data = file.read(chunk_size) if not data: break try: p.feed(data) except zlib.error as e: # ignore zlib complaining on truncated stream, just feed more # data to parser (ticket #19457). if e.args[0].startswith("Error -5"): pass else: raise if p.image: return p.image.size chunk_size *= 2 return None finally: if close: file.close() else: file.seek(file_pos)
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