mirror of
https://github.com/Hopiu/django-imagekit.git
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8c9a9b8d5c
At first, we only had a small amount of code for preserving transparency in `img_to_fobj`, but as that code grew it became apparent that it really didn't belong in the utility function. This commit creates an `AutoConvert` processor which is automatically run before saving unless you disable it by passing `autoconvert=False` to your `ImageSpec` or `ProcessedImageField` constructor. `img_to_fobj` is once again a simple utility function for creating a file object from a PIL image.
143 lines
3.6 KiB
Python
143 lines
3.6 KiB
Python
import os
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import tempfile
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import types
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from django.utils.functional import wraps
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from imagekit.lib import Image, ImageFile
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def img_to_fobj(img, format, **kwargs):
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tmp = tempfile.TemporaryFile()
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try:
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img.save(tmp, format, **kwargs)
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except IOError:
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# PIL can have problems saving large JPEGs if MAXBLOCK isn't big enough,
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# So if we have a problem saving, we temporarily increase it. See
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# http://github.com/jdriscoll/django-imagekit/issues/50
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old_maxblock = ImageFile.MAXBLOCK
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ImageFile.MAXBLOCK = img.size[0] * img.size[1]
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try:
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img.save(tmp, format, **kwargs)
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finally:
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ImageFile.MAXBLOCK = old_maxblock
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tmp.seek(0)
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return tmp
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def get_spec_files(instance):
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try:
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ik = getattr(instance, '_ik')
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except AttributeError:
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return []
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else:
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return [getattr(instance, n) for n in ik.spec_file_names]
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def open_image(target):
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if hasattr(target, 'mode') and 'w' in target.mode and os.path.exists(target.name):
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# target is a file like object with write mode enabled
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# PIL will zero this file out and then give and IO error
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# instead just pass PIL the path
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target = target.name
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img = Image.open(target)
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img.copy = types.MethodType(_wrap_copy(img.copy), img, img.__class__)
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return img
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def _wrap_copy(f):
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@wraps(f)
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def copy(self):
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img = f()
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try:
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img.app = self.app
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except AttributeError:
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pass
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try:
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img._getexif = self._getexif
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except AttributeError:
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pass
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return img
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return copy
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class UnknownExtensionError(Exception):
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pass
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class UnknownFormatError(Exception):
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pass
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_pil_init = 0
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def _preinit_pil():
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"""Loads the standard PIL file format drivers. Returns True if ``preinit()``
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was called (and there's a potential that more drivers were loaded) or False
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if there is no possibility that new drivers were loaded.
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"""
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global _pil_init
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if _pil_init < 1:
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Image.preinit()
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_pil_init = 1
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return True
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return False
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def _init_pil():
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"""Loads all PIL file format drivers. Returns True if ``init()`` was called
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(and there's a potential that more drivers were loaded) or False if there is
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no possibility that new drivers were loaded.
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"""
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global _pil_init
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_preinit_pil()
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if _pil_init < 2:
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Image.init()
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_pil_init = 2
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return True
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return False
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def _extension_to_format(extension):
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return Image.EXTENSION.get(extension.lower())
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def _format_to_extension(format):
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if format:
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for k, v in Image.EXTENSION.iteritems():
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if v == format.upper():
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return k
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return None
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def extension_to_format(extension):
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"""Returns the format that corresponds to the provided extension.
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"""
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format = _extension_to_format(extension)
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if not format and _preinit_pil():
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format = _extension_to_format(extension)
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if not format and _init_pil():
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format = _extension_to_format(extension)
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if not format:
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raise UnknownExtensionError(extension)
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return format
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def format_to_extension(format):
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"""Returns the first extension that matches the provided format.
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"""
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extension = None
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if format:
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extension = _format_to_extension(format)
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if not extension and _preinit_pil():
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extension = _format_to_extension(format)
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if not extension and _init_pil():
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extension = _format_to_extension(format)
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if not extension:
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raise UnknownFormatError(format)
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return extension
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