#!/usr/local/bin/python # # Exif information decoder # Written by Thierry Bousch # Public Domain # # $Id: exifdump.py,v 1.14 2004/01/30 02:11:14 bousch Exp $ # # Since I don't have a copy of the Exif standard, I got most of the # information from the TIFF/EP draft International Standard: # # ISO/DIS 12234-2 # Photography - Electronic still picture cameras - Removable Memory # Part 2: Image data format - TIFF/EP # # You can (and should) get a copy of this document from PIMA's web site; # their URL is: http://www.pima.net/it10a.htm # You'll also find there some documentation on DCF (Digital Camera Format) # which is based on Exif. # # Another must-read is the TIFF 6.0 specification, which can be # obtained from Adobe's FTP site, at # ftp://ftp.adobe.com/pub/adobe/devrelations/devtechnotes/pdffiles/tiff6.pdf # # Many thanks to Doraneko for filling the # holes in the Exif tag list. import sys EXIF_TAGS = { 0x100: "ImageWidth", 0x101: "ImageLength", 0x102: "BitsPerSample", 0x103: "Compression", 0x106: "PhotometricInterpretation", 0x10A: "FillOrder", 0x10D: "DocumentName", 0x10E: "ImageDescription", 0x10F: "Make", 0x110: "Model", 0x111: "StripOffsets", 0x112: "Orientation", 0x115: "SamplesPerPixel", 0x116: "RowsPerStrip", 0x117: "StripByteCounts", 0x11A: "XResolution", 0x11B: "YResolution", 0x11C: "PlanarConfiguration", 0x128: "ResolutionUnit", 0x12D: "TransferFunction", 0x131: "Software", 0x132: "DateTime", 0x13B: "Artist", 0x13E: "WhitePoint", 0x13F: "PrimaryChromaticities", 0x156: "TransferRange", 0x200: "JPEGProc", 0x201: "JPEGInterchangeFormat", 0x202: "JPEGInterchangeFormatLength", 0x211: "YCbCrCoefficients", 0x212: "YCbCrSubSampling", 0x213: "YCbCrPositioning", 0x214: "ReferenceBlackWhite", 0x828F: "BatteryLevel", 0x8298: "Copyright", 0x829A: "ExposureTime", 0x829D: "FNumber", 0x83BB: "IPTC/NAA", 0x8769: "ExifIFDPointer", 0x8773: "InterColorProfile", 0x8822: "ExposureProgram", 0x8824: "SpectralSensitivity", 0x8825: "GPSInfoIFDPointer", 0x8827: "ISOSpeedRatings", 0x8828: "OECF", 0x9000: "ExifVersion", 0x9003: "DateTimeOriginal", 0x9004: "DateTimeDigitized", 0x9101: "ComponentsConfiguration", 0x9102: "CompressedBitsPerPixel", 0x9201: "ShutterSpeedValue", 0x9202: "ApertureValue", 0x9203: "BrightnessValue", 0x9204: "ExposureBiasValue", 0x9205: "MaxApertureValue", 0x9206: "SubjectDistance", 0x9207: "MeteringMode", 0x9208: "LightSource", 0x9209: "Flash", 0x920A: "FocalLength", 0x9214: "SubjectArea", 0x927C: "MakerNote", 0x9286: "UserComment", 0x9290: "SubSecTime", 0x9291: "SubSecTimeOriginal", 0x9292: "SubSecTimeDigitized", 0xA000: "FlashPixVersion", 0xA001: "ColorSpace", 0xA002: "PixelXDimension", 0xA003: "PixelYDimension", 0xA004: "RelatedSoundFile", 0xA005: "InteroperabilityIFDPointer", 0xA20B: "FlashEnergy", # 0x920B in TIFF/EP 0xA20C: "SpatialFrequencyResponse", # 0x920C - - 0xA20E: "FocalPlaneXResolution", # 0x920E - - 0xA20F: "FocalPlaneYResolution", # 0x920F - - 0xA210: "FocalPlaneResolutionUnit", # 0x9210 - - 0xA214: "SubjectLocation", # 0x9214 - - 0xA215: "ExposureIndex", # 0x9215 - - 0xA217: "SensingMethod", # 0x9217 - - 0xA300: "FileSource", 0xA301: "SceneType", 0xA302: "CFAPattern", # 0x828E in TIFF/EP 0xA401: "CustomRendered", 0xA402: "ExposureMode", 0xA403: "WhiteBalance", 0xA404: "DigitalZoomRatio", 0xA405: "FocalLengthIn35mmFilm", 0xA406: "SceneCaptureType", 0xA407: "GainControl", 0xA408: "Contrast", 0xA409: "Saturation", 0xA40A: "Sharpness", 0xA40B: "DeviceSettingDescription", 0xA40C: "SubjectDistanceRange", 0xA420: "ImageUniqueID", } INTR_TAGS = { 0x1: "InteroperabilityIndex", 0x2: "InteroperabilityVersion", 0x1000: "RelatedImageFileFormat", 0x1001: "RelatedImageWidth", 0x1002: "RelatedImageLength", } GPS_TAGS = { 0x0: "GPSVersionID", 0x1: "GPSLatitudeRef", 0x2: "GPSLatitude", 0x3: "GPSLongitudeRef", 0x4: "GPSLongitude", 0x5: "GPSAltitudeRef", 0x6: "GPSAltitude", 0x7: "GPSTimeStamp", 0x8: "GPSSatellites", 0x9: "GPSStatus", 0xA: "GPSMeasureMode", 0xB: "GPSDOP", 0xC: "GPSSpeedRef", 0xD: "GPSSpeed", 0xE: "GPSTrackRef", 0xF: "GPSTrack", 0x10: "GPSImgDirectionRef", 0x11: "GPSImgDirection", 0x12: "GPSMapDatum", 0x13: "GPSDestLatitudeRef", 0x14: "GPSDestLatitude", 0x15: "GPSDestLongitudeRef", 0x16: "GPSDestLongitude", 0x17: "GPSDestBearingRef", 0x18: "GPSDestBearing", 0x19: "GPSDestDistanceRef", 0x1A: "GPSDestDistance", 0x1B: "GPSProcessingMethod", 0x1C: "GPSAreaInformation", 0x1D: "GPSDateStamp", 0x1E: "GPSDifferential" } def s2n_motorola(str): x = 0 for c in str: x = (x << 8) | ord(c) return x def s2n_intel(str): x = 0 y = 0 for c in str: x = x | (ord(c) << y) y = y + 8 return x class Fraction: def __init__(self, num, den): self.num = num self.den = den def __repr__(self): # String representation return '%d/%d' % (self.num, self.den) class TIFF_file: def __init__(self, data): self.data = data self.endian = data[0] def s2n(self, offset, length, signed=0): slice = self.data[offset:offset+length] if self.endian == 'I': val = s2n_intel(slice) else: val = s2n_motorola(slice) # Sign extension ? if signed: msb = 1 << (8*length - 1) if val & msb: val = val - (msb << 1) return val def first_IFD(self): return self.s2n(4, 4) def next_IFD(self, ifd): entries = self.s2n(ifd, 2) return self.s2n(ifd + 2 + 12 * entries, 4) def list_IFDs(self): i = self.first_IFD() a = [] while i: a.append(i) i = self.next_IFD(i) return a def dump_IFD(self, ifd): entries = self.s2n(ifd, 2) a = [] for i in range(entries): entry = ifd + 2 + 12*i tag = self.s2n(entry, 2) type = self.s2n(entry+2, 2) if not 1 <= type <= 10: continue # not handled typelen = [ 1, 1, 2, 4, 8, 1, 1, 2, 4, 8 ] [type-1] count = self.s2n(entry+4, 4) offset = entry+8 if count*typelen > 4: offset = self.s2n(offset, 4) if type == 2: # Special case: nul-terminated ASCII string values = self.data[offset:offset+count-1] else: values = [] signed = (type == 6 or type >= 8) for j in range(count): if type % 5: # Not a fraction value_j = self.s2n(offset, typelen, signed) else: # The type is either 5 or 10 value_j = Fraction(self.s2n(offset, 4, signed), self.s2n(offset+4, 4, signed)) values.append(value_j) offset = offset + typelen # Now "values" is either a string or an array a.append((tag,type,values)) return a def print_IFD(fields, dict=EXIF_TAGS): for (tag,type,values) in fields: try: stag = dict[tag] except: stag = '0x%04X' % tag stype = ['B', # BYTE 'A', # ASCII 'S', # SHORT 'L', # LONG 'R', # RATIONAL 'SB', # SBYTE 'U', # UNDEFINED 'SS', # SSHORT 'SL', # SLONG 'SR', # SRATIONAL ] [type-1] print ' %s(%s)=%s' % (stag,stype,repr(values)) def process_file(file): data = file.read(12) if data[0:4] <> '\377\330\377\341' or data[6:10] <> 'Exif': print ' Not an Exif file' return 1 length = ord(data[4])*256 + ord(data[5]) print ' Exif header length: %d bytes,' % length, data = file.read(length-8) if 0: # that's for debugging only open('exif.header','wb').write(data) print {'I':'Intel', 'M':'Motorola'}[data[0]], 'format' T = TIFF_file(data) L = T.list_IFDs() for i in range(len(L)): print ' IFD %d' % i, if i == 0: print '(main image)', if i == 1: print '(thumbnail)', print 'at offset %d:' % L[i] IFD = T.dump_IFD(L[i]) print_IFD(IFD) exif_off = gps_off = 0 for tag,type,values in IFD: if tag == 0x8769: exif_off = values[0] if tag == 0x8825: gps_off = values[0] if exif_off: print ' Exif SubIFD at offset %d:' % exif_off IFD = T.dump_IFD(exif_off) print_IFD(IFD) # Recent digital cameras have a little subdirectory # here, pointed to by tag 0xA005. Apparently, it's the # "Interoperability IFD", defined in Exif 2.1 and DCF. intr_off = 0 for tag,type,values in IFD: if tag == 0xA005: intr_off = values[0] if intr_off: print ' Exif Interoperability SubSubIFD at offset %d:' % intr_off IFD = T.dump_IFD(intr_off) print_IFD(IFD, dict=INTR_TAGS) if gps_off: print ' GPS SubIFD at offset %d:' % gps_off IFD = T.dump_IFD(gps_off) print_IFD(IFD, dict=GPS_TAGS) return 0 def main(): if len(sys.argv) < 2: sys.stderr.write('Usage: %s files...\n' % sys.argv[0]) sys.exit(2) for filename in sys.argv[1:]: print filename+':' try: file = open(filename, 'rb') process_file(file) except IOError: print ' Cannot open file' sys.exit(0) if __name__ == '__main__': main()