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File: thumbspage/piexif/_load.py
import struct
import sys
from ._common import *
from ._exceptions import InvalidImageDataError
from ._exif import *
from piexif import _webp
LITTLE_ENDIAN = b"\x49\x49"
def load(input_data, key_is_name=False):
"""
py:function:: piexif.load(filename)
Return exif data as dict. Keys(IFD name), be contained, are "0th", "Exif", "GPS", "Interop", "1st", and "thumbnail". Without "thumbnail", the value is dict(tag name/tag value). "thumbnail" value is JPEG as bytes.
:param str filename: JPEG or TIFF
:return: Exif data({"0th":dict, "Exif":dict, "GPS":dict, "Interop":dict, "1st":dict, "thumbnail":bytes})
:rtype: dict
"""
exif_dict = {"0th":{},
"Exif":{},
"GPS":{},
"Interop":{},
"1st":{},
"thumbnail":None}
exifReader = _ExifReader(input_data)
if exifReader.tiftag is None:
return exif_dict
if exifReader.tiftag[0:2] == LITTLE_ENDIAN:
exifReader.endian_mark = "<"
else:
exifReader.endian_mark = ">"
pointer = struct.unpack(exifReader.endian_mark + "L",
exifReader.tiftag[4:8])[0]
exif_dict["0th"] = exifReader.get_ifd_dict(pointer, "0th")
first_ifd_pointer = exif_dict["0th"].pop("first_ifd_pointer")
if ImageIFD.ExifTag in exif_dict["0th"]:
pointer = exif_dict["0th"][ImageIFD.ExifTag]
exif_dict["Exif"] = exifReader.get_ifd_dict(pointer, "Exif")
if ImageIFD.GPSTag in exif_dict["0th"]:
pointer = exif_dict["0th"][ImageIFD.GPSTag]
exif_dict["GPS"] = exifReader.get_ifd_dict(pointer, "GPS")
if ExifIFD.InteroperabilityTag in exif_dict["Exif"]:
pointer = exif_dict["Exif"][ExifIFD.InteroperabilityTag]
exif_dict["Interop"] = exifReader.get_ifd_dict(pointer, "Interop")
if first_ifd_pointer != b"\x00\x00\x00\x00":
pointer = struct.unpack(exifReader.endian_mark + "L",
first_ifd_pointer)[0]
exif_dict["1st"] = exifReader.get_ifd_dict(pointer, "1st")
if (ImageIFD.JPEGInterchangeFormat in exif_dict["1st"] and
ImageIFD.JPEGInterchangeFormatLength in exif_dict["1st"]):
end = (exif_dict["1st"][ImageIFD.JPEGInterchangeFormat] +
exif_dict["1st"][ImageIFD.JPEGInterchangeFormatLength])
thumb = exifReader.tiftag[exif_dict["1st"][ImageIFD.JPEGInterchangeFormat]:end]
exif_dict["thumbnail"] = thumb
if key_is_name:
exif_dict = _get_key_name_dict(exif_dict)
return exif_dict
class _ExifReader(object):
def __init__(self, data):
# Prevents "UnicodeWarning: Unicode equal comparison failed" warnings on Python 2
maybe_image = sys.version_info >= (3,0,0) or isinstance(data, str)
if maybe_image and data[0:2] == b"\xff\xd8": # JPEG
segments = split_into_segments(data)
app1 = get_exif_seg(segments)
if app1:
self.tiftag = app1[10:]
else:
self.tiftag = None
elif maybe_image and data[0:2] in (b"\x49\x49", b"\x4d\x4d"): # TIFF
self.tiftag = data
elif maybe_image and data[0:4] == b"RIFF" and data[8:12] == b"WEBP":
self.tiftag = _webp.get_exif(data)
elif maybe_image and data[0:4] == b"Exif": # Exif
self.tiftag = data[6:]
else:
with open(data, 'rb') as f:
magic_number = f.read(2)
if magic_number == b"\xff\xd8": # JPEG
app1 = read_exif_from_file(data)
if app1:
self.tiftag = app1[10:]
else:
self.tiftag = None
elif magic_number in (b"\x49\x49", b"\x4d\x4d"): # TIFF
with open(data, 'rb') as f:
self.tiftag = f.read()
else:
with open(data, 'rb') as f:
header = f.read(12)
if header[0:4] == b"RIFF"and header[8:12] == b"WEBP":
with open(data, 'rb') as f:
file_data = f.read()
self.tiftag = _webp.get_exif(file_data)
else:
raise InvalidImageDataError("Given file is neither JPEG nor TIFF.")
def get_ifd_dict(self, pointer, ifd_name, read_unknown=False):
ifd_dict = {}
tag_count = struct.unpack(self.endian_mark + "H",
self.tiftag[pointer: pointer+2])[0]
offset = pointer + 2
if ifd_name in ["0th", "1st"]:
t = "Image"
else:
t = ifd_name
p_and_value = []
for x in range(tag_count):
pointer = offset + 12 * x
tag = struct.unpack(self.endian_mark + "H",
self.tiftag[pointer: pointer+2])[0]
value_type = struct.unpack(self.endian_mark + "H",
self.tiftag[pointer + 2: pointer + 4])[0]
value_num = struct.unpack(self.endian_mark + "L",
self.tiftag[pointer + 4: pointer + 8]
)[0]
value = self.tiftag[pointer+8: pointer+12]
p_and_value.append((pointer, value_type, value_num, value))
v_set = (value_type, value_num, value, tag)
if tag in TAGS[t]:
ifd_dict[tag] = self.convert_value(v_set)
elif read_unknown:
ifd_dict[tag] = (v_set[0], v_set[1], v_set[2], self.tiftag)
#else:
# pass
if ifd_name == "0th":
pointer = offset + 12 * tag_count
ifd_dict["first_ifd_pointer"] = self.tiftag[pointer:pointer + 4]
return ifd_dict
def convert_value(self, val):
data = None
t = val[0]
length = val[1]
value = val[2]
if t == TYPES.Byte: # BYTE
if length > 4:
pointer = struct.unpack(self.endian_mark + "L", value)[0]
data = struct.unpack("B" * length,
self.tiftag[pointer: pointer + length])
else:
data = struct.unpack("B" * length, value[0:length])
elif t == TYPES.Ascii: # ASCII
if length > 4:
pointer = struct.unpack(self.endian_mark + "L", value)[0]
data = self.tiftag[pointer: pointer+length - 1]
else:
data = value[0: length - 1]
elif t == TYPES.Short: # SHORT
if length > 2:
pointer = struct.unpack(self.endian_mark + "L", value)[0]
data = struct.unpack(self.endian_mark + "H" * length,
self.tiftag[pointer: pointer+length*2])
else:
data = struct.unpack(self.endian_mark + "H" * length,
value[0:length * 2])
elif t == TYPES.Long: # LONG
if length > 1:
pointer = struct.unpack(self.endian_mark + "L", value)[0]
data = struct.unpack(self.endian_mark + "L" * length,
self.tiftag[pointer: pointer+length*4])
else:
data = struct.unpack(self.endian_mark + "L" * length,
value)
elif t == TYPES.Rational: # RATIONAL
pointer = struct.unpack(self.endian_mark + "L", value)[0]
if length > 1:
data = tuple(
(struct.unpack(self.endian_mark + "L",
self.tiftag[pointer + x * 8:
pointer + 4 + x * 8])[0],
struct.unpack(self.endian_mark + "L",
self.tiftag[pointer + 4 + x * 8:
pointer + 8 + x * 8])[0])
for x in range(length)
)
else:
data = (struct.unpack(self.endian_mark + "L",
self.tiftag[pointer: pointer + 4])[0],
struct.unpack(self.endian_mark + "L",
self.tiftag[pointer + 4: pointer + 8]
)[0])
elif t == TYPES.SByte: # SIGNED BYTES
if length > 4:
pointer = struct.unpack(self.endian_mark + "L", value)[0]
data = struct.unpack("b" * length,
self.tiftag[pointer: pointer + length])
else:
data = struct.unpack("b" * length, value[0:length])
elif t == TYPES.Undefined: # UNDEFINED BYTES
if length > 4:
pointer = struct.unpack(self.endian_mark + "L", value)[0]
data = self.tiftag[pointer: pointer+length]
else:
data = value[0:length]
elif t == TYPES.SShort: # SIGNED SHORT
if length > 2:
pointer = struct.unpack(self.endian_mark + "L", value)[0]
data = struct.unpack(self.endian_mark + "h" * length,
self.tiftag[pointer: pointer+length*2])
else:
data = struct.unpack(self.endian_mark + "h" * length,
value[0:length * 2])
elif t == TYPES.SLong: # SLONG
if length > 1:
pointer = struct.unpack(self.endian_mark + "L", value)[0]
data = struct.unpack(self.endian_mark + "l" * length,
self.tiftag[pointer: pointer+length*4])
else:
data = struct.unpack(self.endian_mark + "l" * length,
value)
elif t == TYPES.SRational: # SRATIONAL
pointer = struct.unpack(self.endian_mark + "L", value)[0]
if length > 1:
data = tuple(
(struct.unpack(self.endian_mark + "l",
self.tiftag[pointer + x * 8: pointer + 4 + x * 8])[0],
struct.unpack(self.endian_mark + "l",
self.tiftag[pointer + 4 + x * 8: pointer + 8 + x * 8])[0])
for x in range(length)
)
else:
data = (struct.unpack(self.endian_mark + "l",
self.tiftag[pointer: pointer + 4])[0],
struct.unpack(self.endian_mark + "l",
self.tiftag[pointer + 4: pointer + 8]
)[0])
elif t == TYPES.Float: # FLOAT
if length > 1:
pointer = struct.unpack(self.endian_mark + "L", value)[0]
data = struct.unpack(self.endian_mark + "f" * length,
self.tiftag[pointer: pointer+length*4])
else:
data = struct.unpack(self.endian_mark + "f" * length,
value)
elif t == TYPES.DFloat: # DOUBLE
pointer = struct.unpack(self.endian_mark + "L", value)[0]
data = struct.unpack(self.endian_mark + "d" * length,
self.tiftag[pointer: pointer+length*8])
else:
raise ValueError("Exif might be wrong. Got incorrect value " +
"type to decode.\n" +
"tag: " + str(val[3]) + "\ntype: " + str(t))
if isinstance(data, tuple) and (len(data) == 1):
return data[0]
else:
return data
def _get_key_name_dict(exif_dict):
new_dict = {
"0th":{TAGS["Image"][n]["name"]:value for n, value in exif_dict["0th"].items()},
"Exif":{TAGS["Exif"][n]["name"]:value for n, value in exif_dict["Exif"].items()},
"1st":{TAGS["Image"][n]["name"]:value for n, value in exif_dict["1st"].items()},
"GPS":{TAGS["GPS"][n]["name"]:value for n, value in exif_dict["GPS"].items()},
"Interop":{TAGS["Interop"][n]["name"]:value for n, value in exif_dict["Interop"].items()},
"thumbnail":exif_dict["thumbnail"],
}
return new_dict