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mat2/libmat2/images.py
Antoine Tenart f068621628 libmat2: images: fix handling of .JPG files
Pixbuf only supports .jpeg files, not .jpg, so libmat2 looks for such an
extension and converts it if necessary. As this check is case sensitive,
processing .JPG files does not work.

Fixes #47.

Signed-off-by: Antoine Tenart <antoine.tenart@ack.tf>
2018-08-23 20:43:27 +02:00

121 lines
4.5 KiB
Python

import subprocess
import imghdr
import json
import os
import shutil
import tempfile
import re
from typing import Set
import cairo
import gi
gi.require_version('GdkPixbuf', '2.0')
from gi.repository import GdkPixbuf
from . import abstract
# Make pyflakes happy
assert Set
class _ImageParser(abstract.AbstractParser):
""" Since we use `exiftool` to get metadata from
all images fileformat, `get_meta` is implemented in this class,
and all the image-handling ones are inheriting from it."""
meta_whitelist = set() # type: Set[str]
@staticmethod
def __handle_problematic_filename(filename: str, callback) -> str:
""" This method takes a filename with a problematic name,
and safely applies it a `callback`."""
tmpdirname = tempfile.mkdtemp()
fname = os.path.join(tmpdirname, "temp_file")
shutil.copy(filename, fname)
out = callback(fname)
shutil.rmtree(tmpdirname)
return out
def get_meta(self):
""" There is no way to escape the leading(s) dash(es) of the current
self.filename to prevent parameter injections, so we need to take care
of this.
"""
fun = lambda f: subprocess.check_output(['/usr/bin/exiftool', '-json', f])
if re.search('^[a-z0-9/]', self.filename) is None:
out = self.__handle_problematic_filename(self.filename, fun)
else:
out = fun(self.filename)
meta = json.loads(out.decode('utf-8'))[0]
for key in self.meta_whitelist:
meta.pop(key, None)
return meta
class PNGParser(_ImageParser):
mimetypes = {'image/png', }
meta_whitelist = {'SourceFile', 'ExifToolVersion', 'FileName',
'Directory', 'FileSize', 'FileModifyDate',
'FileAccessDate', 'FileInodeChangeDate',
'FilePermissions', 'FileType', 'FileTypeExtension',
'MIMEType', 'ImageWidth', 'BitDepth', 'ColorType',
'Compression', 'Filter', 'Interlace', 'BackgroundColor',
'ImageSize', 'Megapixels', 'ImageHeight'}
def __init__(self, filename):
super().__init__(filename)
try: # better fail here than later
cairo.ImageSurface.create_from_png(self.filename)
except MemoryError:
raise ValueError
def remove_all(self):
surface = cairo.ImageSurface.create_from_png(self.filename)
surface.write_to_png(self.output_filename)
return True
class GdkPixbufAbstractParser(_ImageParser):
""" GdkPixbuf can handle a lot of surfaces, so we're rending images on it,
this has the side-effect of completely removing metadata.
"""
_type = ''
def remove_all(self):
_, extension = os.path.splitext(self.filename)
pixbuf = GdkPixbuf.Pixbuf.new_from_file(self.filename)
if extension.lower() == '.jpg':
extension = '.jpeg' # gdk is picky
pixbuf.savev(self.output_filename, extension[1:], [], [])
return True
def __init__(self, filename):
super().__init__(filename)
if imghdr.what(filename) != self._type: # better safe than sorry
raise ValueError
class JPGParser(GdkPixbufAbstractParser):
_type = 'jpeg'
mimetypes = {'image/jpeg'}
meta_whitelist = {'SourceFile', 'ExifToolVersion', 'FileName',
'Directory', 'FileSize', 'FileModifyDate',
'FileAccessDate', "FileInodeChangeDate",
'FilePermissions', 'FileType', 'FileTypeExtension',
'MIMEType', 'ImageWidth', 'ImageSize', 'BitsPerSample',
'ColorComponents', 'EncodingProcess', 'JFIFVersion',
'ResolutionUnit', 'XResolution', 'YCbCrSubSampling',
'YResolution', 'Megapixels', 'ImageHeight'}
class TiffParser(GdkPixbufAbstractParser):
_type = 'tiff'
mimetypes = {'image/tiff'}
meta_whitelist = {'Compression', 'ExifByteOrder', 'ExtraSamples',
'FillOrder', 'PhotometricInterpretation',
'PlanarConfiguration', 'RowsPerStrip', 'SamplesPerPixel',
'StripByteCounts', 'StripOffsets', 'BitsPerSample',
'Directory', 'ExifToolVersion', 'FileAccessDate',
'FileInodeChangeDate', 'FileModifyDate', 'FileName',
'FilePermissions', 'FileSize', 'FileType',
'FileTypeExtension', 'ImageHeight', 'ImageSize',
'ImageWidth', 'MIMEType', 'Megapixels', 'SourceFile'}