Fix EXIF support.

This commit is contained in:
Antony Lee 2014-12-30 11:57:45 +01:00 committed by wiredfool
parent 974bcc074b
commit 56a3f0f2ab
3 changed files with 47 additions and 56 deletions

View File

@ -394,13 +394,6 @@ class JpegImageFile(ImageFile.ImageFile):
return _getmp(self)
def _fixup(value):
# Helper function for _getexif() and _getmp()
if len(value) == 1:
return value[0]
return value
def _getexif(self):
# Extract EXIF information. This method is highly experimental,
# and is likely to be replaced with something better in a future
@ -414,12 +407,10 @@ def _getexif(self):
return None
file = io.BytesIO(data[6:])
head = file.read(8)
exif = {}
# process dictionary
info = TiffImagePlugin.ImageFileDirectory(head)
info.load(file)
for key, value in info.items():
exif[key] = _fixup(value)
exif = dict(info)
# get exif extension
try:
# exif field 0x8769 is an offset pointer to the location
@ -431,8 +422,7 @@ def _getexif(self):
else:
info = TiffImagePlugin.ImageFileDirectory(head)
info.load(file)
for key, value in info.items():
exif[key] = _fixup(value)
exif.update(info)
# get gpsinfo extension
try:
# exif field 0x8825 is an offset pointer to the location
@ -444,9 +434,7 @@ def _getexif(self):
else:
info = TiffImagePlugin.ImageFileDirectory(head)
info.load(file)
exif[0x8825] = gps = {}
for key, value in info.items():
gps[key] = _fixup(value)
exif[0x8825] = dict(info)
return exif
@ -464,12 +452,10 @@ def _getmp(self):
file_contents = io.BytesIO(data)
head = file_contents.read(8)
endianness = '>' if head[:4] == b'\x4d\x4d\x00\x2a' else '<'
mp = {}
# process dictionary
info = TiffImagePlugin.ImageFileDirectory(head)
info.load(file_contents)
for key, value in info.items():
mp[key] = _fixup(value)
mp = dict(info)
# it's an error not to have a number of images
try:
quant = mp[0xB001]

View File

@ -253,18 +253,28 @@ class ImageFileDirectory(collections.MutableMapping):
really sure what they're doing.
"""
def __init__(self, prefix=II):
def __init__(self, ifh=b"II\052\0\0\0\0\0", prefix=None):
"""Initialize an ImageFileDirectory.
To construct an ImageFileDirectory from a real file, pass the 8-byte
magic header to the constructor. To only set the endianness, pass it
as the 'prefix' keyword argument.
:ifh: One of the accepted magic headers (cf. PREFIXES); also sets
endianness.
:prefix: Override the endianness of the file.
"""
:prefix: "II"|"MM" tiff endianness
"""
self._prefix = prefix
if prefix == MM:
if ifh[:4] not in PREFIXES:
raise SyntaxError("not a TIFF file (header %r not valid)" % ifh)
self._prefix = prefix if prefix is not None else ifh[:2]
if self._prefix == MM:
self._endian = ">"
elif prefix == II:
elif self._prefix == II:
self._endian = "<"
else:
raise ValueError("not a TIFF IFD")
raise SyntaxError("not a TIFF IFD")
self.reset()
self.next, = self._unpack("L", ifh[4:])
prefix = property(lambda self: self._prefix)
offset = property(lambda self: self._offset)
@ -360,10 +370,10 @@ class ImageFileDirectory(collections.MutableMapping):
def __iter__(self):
return itertools.chain(list(self._tags), list(self._tagdata))
def unpack(self, fmt, data):
def _unpack(self, fmt, data):
return struct.unpack(self._endian + fmt, data)
def pack(self, fmt, *values):
def _pack(self, fmt, *values):
return struct.pack(self._endian + fmt, *values)
def _register_loader(idx, size):
@ -387,9 +397,9 @@ class ImageFileDirectory(collections.MutableMapping):
TYPES[idx] = name
size = struct.calcsize("=" + fmt)
_load_dispatch[idx] = size, lambda self, data: (
self.unpack("{}{}".format(len(data) // size, fmt), data))
self._unpack("{}{}".format(len(data) // size, fmt), data))
_write_dispatch[idx] = lambda self, *values: (
b"".join(self.pack(fmt, value) for value in values))
b"".join(self._pack(fmt, value) for value in values))
list(map(_register_basic,
[(1, "B", "byte"), (3, "H", "short"), (4, "L", "long"),
@ -411,12 +421,12 @@ class ImageFileDirectory(collections.MutableMapping):
@_register_loader(5, 8)
def load_rational(self, data):
vals = self.unpack("{}L".format(len(data) // 4), data)
vals = self._unpack("{}L".format(len(data) // 4), data)
return tuple(num / denom for num, denom in zip(vals[::2], vals[1::2]))
@_register_writer(5)
def write_rational(self, *values):
return b"".join(self.pack("2L", *_limit_rational(frac, 2 ** 31))
return b"".join(self._pack("2L", *_limit_rational(frac, 2 ** 31))
for frac in values)
@_register_loader(7, 1)
@ -429,12 +439,12 @@ class ImageFileDirectory(collections.MutableMapping):
@_register_loader(10, 8)
def load_signed_rational(self, data):
vals = self.unpack("{}l".format(len(data) // 4), data)
vals = self._unpack("{}l".format(len(data) // 4), data)
return tuple(num / denom for num, denom in zip(vals[::2], vals[1::2]))
@_register_writer(10)
def write_signed_rational(self, *values):
return b"".join(self.pack("2L", *_limit_rational(frac, 2 ** 30))
return b"".join(self._pack("2L", *_limit_rational(frac, 2 ** 30))
for frac in values)
def load(self, fp):
@ -442,9 +452,9 @@ class ImageFileDirectory(collections.MutableMapping):
self.reset()
self._offset = fp.tell()
for i in range(self.unpack("H", fp.read(2))[0]):
tag, typ, count, data = self.unpack("HHL4s", fp.read(12))
if DEBUG:
for i in range(self._unpack("H", fp.read(2))[0]):
tag, typ, count, data = self._unpack("HHL4s", fp.read(12))
if Image.DEBUG:
tagname = TAGS.get(tag, TagInfo()).name
typname = TYPES.get(typ, "unknown")
print("tag: %s (%d) - type: %s (%d)" %
@ -459,8 +469,8 @@ class ImageFileDirectory(collections.MutableMapping):
size = count * unit_size
if size > 4:
here = fp.tell()
offset, = self.unpack("L", data)
if DEBUG:
offset, = self._unpack("L", data)
if Image.DEBUG:
print("Tag Location: %s - Data Location: %s" %
(here, offset), end=" ")
fp.seek(offset)
@ -484,12 +494,16 @@ class ImageFileDirectory(collections.MutableMapping):
else:
print("- value:", self[tag])
self.next, = self.unpack("L", fp.read(4))
self.next, = self._unpack("L", fp.read(4))
def save(self, fp):
if fp.tell() == 0: # skip TIFF header on subsequent pages
# tiff header -- PIL always starts the first IFD at offset 8
fp.write(self._prefix + self._pack("HL", 42, 8))
# FIXME What about tagdata?
fp.write(self.pack("H", len(self._tags)))
fp.write(self._pack("H", len(self._tags)))
entries = []
offset = fp.tell() + len(self._tags) * 12 + 4
@ -521,7 +535,7 @@ class ImageFileDirectory(collections.MutableMapping):
if len(data) <= 4:
entries.append((tag, typ, count, data.ljust(4, b"\0"), b""))
else:
entries.append((tag, typ, count, self.pack("L", offset), data))
entries.append((tag, typ, count, self._pack("L", offset), data))
offset += (len(data) + 1) // 2 * 2 # pad to word
# update strip offset data to point beyond auxiliary data
@ -530,14 +544,14 @@ class ImageFileDirectory(collections.MutableMapping):
if data:
raise NotImplementedError(
"multistrip support not yet implemented")
value = self.pack("L", self.unpack("L", value)[0] + offset)
value = self._pack("L", self._unpack("L", value)[0] + offset)
entries[stripoffsets] = tag, typ, count, value, data
# pass 2: write entries to file
for tag, typ, count, value, data in entries:
if DEBUG > 1:
print(tag, typ, count, repr(value), repr(data))
fp.write(self.pack("HHL4s", tag, typ, count, value))
fp.write(self._pack("HHL4s", tag, typ, count, value))
# -- overwrite here for multi-page --
fp.write(b"\0\0\0\0") # end of entries
@ -573,14 +587,11 @@ class TiffImageFile(ImageFile.ImageFile):
# Header
ifh = self.fp.read(8)
if ifh[:4] not in PREFIXES:
raise SyntaxError("not a TIFF file")
# image file directory (tag dictionary)
self.tag = self.ifd = ImageFileDirectory(ifh[:2])
self.tag = self.ifd = ImageFileDirectory(ifh)
# setup frame pointers
self.__first, = self.__next, = self.ifd.unpack("L", ifh[4:])
self.__first = self.__next = self.ifd.next
self.__frame = -1
self.__fp = self.fp
self._frame_pos = []
@ -991,7 +1002,7 @@ def _save(im, fp, filename):
except KeyError:
raise IOError("cannot write mode %s as TIFF" % im.mode)
ifd = ImageFileDirectory(prefix)
ifd = ImageFileDirectory(prefix=prefix)
compression = im.encoderinfo.get('compression', im.info.get('compression',
'raw'))
@ -1001,12 +1012,6 @@ def _save(im, fp, filename):
# required for color libtiff images
ifd[PLANAR_CONFIGURATION] = getattr(im, '_planar_configuration', 1)
# -- multi-page -- skip TIFF header on subsequent pages
if not libtiff and fp.tell() == 0:
# tiff header (write via IFD to get everything right)
# PIL always starts the first IFD at offset 8
fp.write(ifd.prefix + ifd.pack("HL", 42, 8))
ifd[IMAGEWIDTH] = im.size[0]
ifd[IMAGELENGTH] = im.size[1]

View File

@ -129,9 +129,9 @@ TAGS = {
33432: ("Copyright", 2, 1),
# FIXME add more tags here
34665: ("ExifIFD", 3, 1),
50741: ("MakerNoteSafety", 3, 1, {0: "Unsafe", 1: "Safe"}),
50780: ("BestQualityScale", 5, 1),
# private tags registered with Adobe
50838: ("ImageJMetaDataByteCounts", 4, 1),
50839: ("ImageJMetaData", 7, 1)
}