ordigi/elodie/media/photo.py

84 lines
2.8 KiB
Python

"""
The photo module contains the :class:`Photo` class, which is used to track
image objects (JPG, DNG, etc.).
.. moduleauthor:: Jaisen Mathai <jaisen@jmathai.com>
"""
import imghdr
import os
import time
from .media import Media
class Photo(Media):
"""A photo object.
:param str source: The fully qualified path to the photo file
"""
__name__ = 'Photo'
#: Valid extensions for photo files.
extensions = ('arw', 'cr2', 'dng', 'gif', 'heic', 'jpeg', 'jpg', 'nef', 'png', 'rw2')
def __init__(self, source=None):
super().__init__(source)
# We only want to parse EXIF once so we store it here
self.exif = None
# Optionally import Pillow - see gh-325
# https://github.com/jmathai/elodie/issues/325
self.pillow = None
try:
from PIL import Image
self.pillow = Image
except ImportError:
pass
def is_valid(self):
"""Check the file extension against valid file extensions.
The list of valid file extensions come from self.extensions. This
also checks whether the file is an image.
:returns: bool
"""
source = self.source
# HEIC is not well supported yet so we special case it.
# https://github.com/python-pillow/Pillow/issues/2806
extension = os.path.splitext(source)[1][1:].lower()
if(extension != 'heic'):
# gh-4 This checks if the source file is an image.
# It doesn't validate against the list of supported types.
# We check with imghdr and pillow.
if(imghdr.what(source) is None):
# Pillow is used as a fallback and if it's not available we trust
# what imghdr returned.
if(self.pillow is None):
return False
else:
# imghdr won't detect all variants of images (https://bugs.python.org/issue28591)
# see https://github.com/jmathai/elodie/issues/281
# before giving up, we use `pillow` imaging library to detect file type
#
# It is important to note that the library doesn't decode or load the
# raster data unless it really has to. When you open a file,
# the file header is read to determine the file format and extract
# things like mode, size, and other properties required to decode the file,
# but the rest of the file is not processed until later.
try:
im = self.pillow.open(source)
except IOError:
return False
if(im.format is None):
return False
return extension in self.extensions