in infrastructure/pillow-layer/python/PIL/JpegImagePlugin.py [0:0]
def APP(self, marker):
#
# Application marker. Store these in the APP dictionary.
# Also look for well-known application markers.
n = i16(self.fp.read(2)) - 2
s = ImageFile._safe_read(self.fp, n)
app = "APP%d" % (marker & 15)
self.app[app] = s # compatibility
self.applist.append((app, s))
if marker == 0xFFE0 and s[:4] == b"JFIF":
# extract JFIF information
self.info["jfif"] = version = i16(s, 5) # version
self.info["jfif_version"] = divmod(version, 256)
# extract JFIF properties
try:
jfif_unit = i8(s[7])
jfif_density = i16(s, 8), i16(s, 10)
except Exception:
pass
else:
if jfif_unit == 1:
self.info["dpi"] = jfif_density
self.info["jfif_unit"] = jfif_unit
self.info["jfif_density"] = jfif_density
elif marker == 0xFFE1 and s[:5] == b"Exif\0":
if "exif" not in self.info:
# extract EXIF information (incomplete)
self.info["exif"] = s # FIXME: value will change
elif marker == 0xFFE2 and s[:5] == b"FPXR\0":
# extract FlashPix information (incomplete)
self.info["flashpix"] = s # FIXME: value will change
elif marker == 0xFFE2 and s[:12] == b"ICC_PROFILE\0":
# Since an ICC profile can be larger than the maximum size of
# a JPEG marker (64K), we need provisions to split it into
# multiple markers. The format defined by the ICC specifies
# one or more APP2 markers containing the following data:
# Identifying string ASCII "ICC_PROFILE\0" (12 bytes)
# Marker sequence number 1, 2, etc (1 byte)
# Number of markers Total of APP2's used (1 byte)
# Profile data (remainder of APP2 data)
# Decoders should use the marker sequence numbers to
# reassemble the profile, rather than assuming that the APP2
# markers appear in the correct sequence.
self.icclist.append(s)
elif marker == 0xFFED and s[:14] == b"Photoshop 3.0\x00":
# parse the image resource block
offset = 14
photoshop = self.info.setdefault("photoshop", {})
while s[offset : offset + 4] == b"8BIM":
try:
offset += 4
# resource code
code = i16(s, offset)
offset += 2
# resource name (usually empty)
name_len = i8(s[offset])
# name = s[offset+1:offset+1+name_len]
offset += 1 + name_len
offset += offset & 1 # align
# resource data block
size = i32(s, offset)
offset += 4
data = s[offset : offset + size]
if code == 0x03ED: # ResolutionInfo
data = {
"XResolution": i32(data[:4]) / 65536,
"DisplayedUnitsX": i16(data[4:8]),
"YResolution": i32(data[8:12]) / 65536,
"DisplayedUnitsY": i16(data[12:]),
}
photoshop[code] = data
offset += size
offset += offset & 1 # align
except struct.error:
break # insufficient data
elif marker == 0xFFEE and s[:5] == b"Adobe":
self.info["adobe"] = i16(s, 5)
# extract Adobe custom properties
try:
adobe_transform = i8(s[1])
except Exception:
pass
else:
self.info["adobe_transform"] = adobe_transform
elif marker == 0xFFE2 and s[:4] == b"MPF\0":
# extract MPO information
self.info["mp"] = s[4:]
# offset is current location minus buffer size
# plus constant header size
self.info["mpoffset"] = self.fp.tell() - n + 4
# If DPI isn't in JPEG header, fetch from EXIF
if "dpi" not in self.info and "exif" in self.info:
try:
exif = self.getexif()
resolution_unit = exif[0x0128]
x_resolution = exif[0x011A]
try:
dpi = float(x_resolution[0]) / x_resolution[1]
except TypeError:
dpi = x_resolution
if resolution_unit == 3: # cm
# 1 dpcm = 2.54 dpi
dpi *= 2.54
self.info["dpi"] = int(dpi + 0.5), int(dpi + 0.5)
except (KeyError, SyntaxError, ValueError, ZeroDivisionError):
# SyntaxError for invalid/unreadable EXIF
# KeyError for dpi not included
# ZeroDivisionError for invalid dpi rational value
# ValueError for x_resolution[0] being an invalid float
self.info["dpi"] = 72, 72