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# Library to extract EXIF information in digital camera image files
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# To use this library call with:
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# f=open(path_name, 'rb')
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# tags=EXIF.process_file(f)
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# tags will now be a dictionary mapping names of EXIF tags to their
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# values in the file named by path_name. You can process the tags
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# as you wish. In particular, you can iterate through all the tags with:
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# for tag in tags.keys():
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# if tag not in ('JPEGThumbnail', 'TIFFThumbnail', 'Filename',
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# print "Key: %s, value %s" % (tag, tags[tag])
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# (This code uses the if statement to avoid printing out a few of the
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# tags that tend to be long or boring.)
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# The tags dictionary will include keys for all of the usual EXIF
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# tags, and will also include keys for Makernotes used by some
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# cameras, for which we have a good specification.
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# Contains code from "exifdump.py" originally written by Thierry Bousch
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# <bousch@topo.math.u-psud.fr> and released into the public domain.
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# Updated and turned into general-purpose library by Gene Cash
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# <email gcash cfl.rr.com>
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# This copyright license is intended to be similar to the FreeBSD license.
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# Copyright 2002 Gene Cash All rights reserved.
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# <email gcash at cfl.rr.com>
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# This copyright license is intended to be similar to the FreeBSD license.
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# Copyright 2002 Gene Cash All rights reserved.
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# Redistribution and use in source and binary forms, with or without
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# modification, are permitted provided that the following conditions are
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# This means you may do anything you want with this code, except claim you
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# wrote it. Also, if it breaks you get to keep both pieces.
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# * Simon J. Gerraty <sjg@crufty.net>
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# s2n fix & orientation decode
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# * John T. Riedl <riedl@cs.umn.edu>
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# Added support for newer Nikon type 3 Makernote format for D70 and some
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# other Nikon cameras.
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# * Joerg Schaefer <schaeferj@gmx.net>
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# Fixed subtle bug when faking an EXIF header, which affected maker notes
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# using relative offsets, and a fix for Nikon D100.
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# 21-AUG-99 TB Last update by Thierry Bousch to his code.
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# 17-JAN-02 CEC Discovered code on web.
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# Commented everything.
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# 26-JAN-02 CEC Added ability to extract TIFF thumbnails.
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# Added Nikon, Fujifilm, Casio MakerNotes.
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# 30-NOV-03 CEC Fixed problem with canon_decode_tag() not creating an
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# IFD_Tag() object. Fixed bit shift warning.
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# 15-FEB-04 CEC Finally fixed bit shift warning by converting Y to 0L.
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# * Better printing of ratios
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# field type descriptions as (length, abbreviation, full name) tuples
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0x010F: ('Make', ),
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0x0110: ('Model', ),
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0x0111: ('StripOffsets', ),
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0x0112: ('Orientation', ),
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0x0112: ('Orientation',
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{1: 'Horizontal (normal)',
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2: 'Mirrored horizontal',
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4: 'Mirrored vertical',
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5: 'Mirrored horizontal then rotated 90 CCW',
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7: 'Mirrored horizontal then rotated 90 CW',
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8: 'Rotated 90 CCW'}),
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0x0115: ('SamplesPerPixel', ),
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0x0116: ('RowsPerStrip', ),
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0x0117: ('StripByteCounts', ),
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0x0006: ('ImageSharpening', ),
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0x0007: ('FocusMode', ),
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0x0008: ('FlashSetting', ),
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0x0009: ('AutoFlashMode', ),
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0x000B: ('WhiteBalanceBias', ),
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0x000C: ('WhiteBalanceRBCoeff', ),
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0x000F: ('ISOSelection', ),
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0x0012: ('FlashCompensation', ),
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0x0013: ('ISOSpeedRequested', ),
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0x0016: ('PhotoCornerCoordinates', ),
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0x0018: ('FlashBracketCompensationApplied', ),
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0x0019: ('AEBracketCompensationApplied', ),
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0x0080: ('ImageAdjustment', ),
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0x0081: ('ToneCompensation', ),
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0x0082: ('AuxiliaryLens', ),
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0x0083: ('LensType', ),
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0x0084: ('LensMinMaxFocalMaxAperture', ),
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0x0085: ('ManualFocusDistance', ),
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0x0086: ('DigitalZoomFactor', ),
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0x0088: ('AFFocusPosition',
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0x0200: 'Bottom',
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0x0400: 'Right'}),
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0x0089: ('BracketingMode',
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{0x00: 'Single frame, no bracketing',
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0x01: 'Continuous, no bracketing',
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0x02: 'Timer, no bracketing',
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0x10: 'Single frame, exposure bracketing',
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0x11: 'Continuous, exposure bracketing',
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0x12: 'Timer, exposure bracketing',
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0x40: 'Single frame, white balance bracketing',
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0x41: 'Continuous, white balance bracketing',
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0x42: 'Timer, white balance bracketing'}),
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0x008D: ('ColorMode', ),
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0x008F: ('SceneMode?', ),
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0x0090: ('LightingType', ),
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0x0092: ('HueAdjustment', ),
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0x0094: ('Saturation',
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0x0095: ('NoiseReduction', ),
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0x00A7: ('TotalShutterReleases', ),
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0x00A9: ('ImageOptimization', ),
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0x00AA: ('Saturation', ),
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0x00AB: ('DigitalVariProgram', ),
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0x0010: ('DataDump', )
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# class that handles an EXIF header
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class EXIF_header:
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def __init__(self, file, endian, offset, debug=0):
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def __init__(self, file, endian, offset, fake_exif, debug=0):
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self.endian=endian
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self.offset=offset
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self.fake_exif=fake_exif
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# convert slice to integer, based on sign and endian flags
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# usually this offset is assumed to be relative to the beginning of the
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# start of the EXIF information. For some cameras that use relative tags,
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# this offset may be relative to some other starting point.
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def s2n(self, offset, length, signed=0):
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self.file.seek(self.offset+offset)
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slice=self.file.read(length)
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# return list of entries in this IFD
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def dump_IFD(self, ifd, ifd_name, dict=EXIF_TAGS):
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def dump_IFD(self, ifd, ifd_name, dict=EXIF_TAGS, relative=0):
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entries=self.s2n(ifd, 2)
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for i in range(entries):
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# entry is index of start of this IFD in the file
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tag=self.s2n(entry, 2)
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# get tag name. We do it early to make debugging easier
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tag_entry=dict.get(tag)
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tag_name=tag_entry[0]
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tag_name='Tag 0x%04X' % tag
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field_type=self.s2n(entry+2, 2)
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if not 0 < field_type < len(FIELD_TYPES):
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# unknown field type
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count=self.s2n(entry+4, 4)
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if count*typelen > 4:
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# not the value, it's a pointer to the value
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offset=self.s2n(offset, 4)
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# offset is not the value; it's a pointer to the value
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# if relative we set things up so s2n will seek to the right
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# place when it adds self.offset. Note that this 'relative'
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# is for the Nikon type 3 makernote. Other cameras may use
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# other relative offsets, which would have to be computed here
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# slightly differently.
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tmp_offset=self.s2n(offset, 4)
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offset=tmp_offset+ifd-self.offset+4
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offset=self.s2n(offset, 4)
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field_offset=offset
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if field_type == 2:
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# special case: null-terminated ASCII string
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self.file.seek(self.offset+offset)
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values=self.file.read(count).strip().replace('\x00','')
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values=self.file.read(count)
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values=values.strip().replace('\x00','')
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# use LUT for this tag
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# use lookup table for this tag
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printable+=tag_entry[1].get(i, repr(i))
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tag_name='Tag 0x%04X' % tag
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self.tags[ifd_name+' '+tag_name]=IFD_Tag(printable, tag,
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values, field_offset,
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print ' %s: %s' % (tag_name,
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repr(self.tags[ifd_name+' '+tag_name]))
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print ' debug: %s: %s' % (tag_name,
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repr(self.tags[ifd_name+' '+tag_name]))
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# extract uncompressed TIFF thumbnail (like pulling teeth)
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# we take advantage of the pre-existing layout in the thumbnail IFD as
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self.tags['TIFFThumbnail']=tiff
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# decode all the camera-specific MakerNote formats
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# Note is the data that comprises this MakerNote. The MakerNote will
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# likely have pointers in it that point to other parts of the file. We'll
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# use self.offset as the starting point for most of those pointers, since
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# they are relative to the beginning of the file.
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# If the MakerNote is in a newer format, it may use relative addressing
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# within the MakerNote. In that case we'll use relative addresses for the
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# As an aside: it's not just to be annoying that the manufacturers use
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# relative offsets. It's so that if the makernote has to be moved by the
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# picture software all of the offsets don't have to be adjusted. Overall,
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# this is probably the right strategy for makernotes, though the spec is
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# ambiguous. (The spec does not appear to imagine that makernotes would
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# follow EXIF format internally. Once they did, it's ambiguous whether
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# the offsets should be from the header at the start of all the EXIF info,
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# or from the header at the start of the makernote.)
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def decode_maker_note(self):
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note=self.tags['EXIF MakerNote']
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make=self.tags['Image Make'].printable
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model=self.tags['Image Model'].printable
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if note.values[0:5] == [78, 105, 107, 111, 110]: # "Nikon"
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# The maker note usually starts with the word Nikon, followed by the
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# type of the makernote (1 or 2, as a short). If the word Nikon is
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# not at the start of the makernote, it's probably type 2, since some
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# cameras work that way.
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if make in ('NIKON', 'NIKON CORPORATION'):
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if note.values[0:7] == [78, 105, 107, 111, 110, 00, 01]:
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print "Looks like a type 1 Nikon MakerNote."
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self.dump_IFD(note.field_offset+8, 'MakerNote',
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dict=MAKERNOTE_NIKON_OLDER_TAGS)
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elif note.values[0:7] == [78, 105, 107, 111, 110, 00, 02]:
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print "Looks like a labeled type 2 Nikon MakerNote"
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if note.values[12:14] != [0, 42] and note.values[12:14] != [42L, 0L]:
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raise ValueError, "Missing marker tag '42' in MakerNote."
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# skip the Makernote label and the TIFF header
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self.dump_IFD(note.field_offset+10+8, 'MakerNote',
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dict=MAKERNOTE_NIKON_NEWER_TAGS, relative=1)
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# newer model (E99x or D1)
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print "Looks like an unlabeled type 2 Nikon MakerNote"
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self.dump_IFD(note.field_offset, 'MakerNote',
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dict=MAKERNOTE_NIKON_NEWER_TAGS)
added
removed
EXIF.py
