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Image::MetaData::JPEG::MakerNotes(3pm) User Contributed Perl Documentation Image::MetaData::JPEG::MakerNotes(3pm)


Image::MetaData::JPEG::MakerNotes - This document contains random information and details on MakerNotes; it is an appendix to the main manual page of the Image::MetaData::JPEG module, which the reader should refer to for further details and the general scope. The note on MakerNote parsing in the main manual page is of particular interest.

Pieces of information available after parsing the MakerNote

The result of the process of parsing the maker note is stored in a directory in the internal data structure for the APP1 Segment, whose path is "IFD@SubIFD@MakerNoteData_$format", where $format is the specific note format; the 'MakerNote' entry in IFD0@SubIFD is then removed. This translation happens always, because there is a catch-all 'unknown' rule for a binary makernote with very broad acceptance rules. The maker note directory contains, in addition, a special subdir with some fields reporting about the parsing process.

    key         content
    --------    -------
    ORIGINAL    the raw content of the maker note (unparsed)
    SIGNATURE   the first few bytes which allowed the format to be chosen
    ENDIANNESS  the byte order chosen during parsing
    FORMAT      the maker note format chosen during parsing
    ERROR       [optional] error details, in case of failure while parsing

Supported MakerNote formats

Maker note formats are specified in a special internal hash, with a key for each format (including the 'unknown' format). Each format entry corresponds to an anonymous hash containing information for parsing the MakerNote; the "normal" format is considered to be an IFD-like MakerNote with a next_link pointer, offsets counted from the global TIFF header and no MakerNote internal TIFF header.

        key         meaning or effect
        ---------   -----------------
        signature   the MakerNote signature (a regular expression)
        maker       the Maker signature (i.e., its name, no regex)
        tags        a reference to a hash for tag translations
    (A) mkntstart   if set, offsets are counted from the maker note start
    (B) mkntTIFF    if set, offsets are counted from the internal TIFF header
    (C) ignore      if set, the format is to be ignored
    (D) nonext      if set, the maker note IFD does not have a next_link
    (E) endianness  if set, the byte order is fixed to this value
    (F) nonIFD      if set, the maker note is not IFD-like

Currently, "supported" formats are described in the following table; authoritative data is indeed kept in, to which the reader should refer for tag definitions and translations. Remember that both the 'signature' and the 'maker' fields are regular expressions matching at the beginning (the real signature corresponds to $1).

                A B C D E F Maker     Signature
                ----------- --------- -----------------
    Agfa                    AGFA      (AGFA \000\001)
    Canon                   Canon     ()
    Casio_1                 CASIO     ()[^Q]
    Casio_2                 CASIO     (QVC\000{3})
    Epson                   EPSON     (EPSON\000\001\000)
    Foveon                  FOVEON    (FOVEON\000{2}\001\000)
    Fujifilm    x           FUJIFILM  (FUJIFILM\014\000{3})
    HPackard        x       Hewlett-Packard    (HP)
    Kyocera     x     x     KYOCERA   (KYOCERA {12}\000{3})
    Kodak               B x KODAK     (KDK INFO[a-zA-Z0-9]*  )
    Minolta_1               MINOLTA   ().{10}MLT0 
    Minolta_2               Minolta   ().{10}MLT0
    Konica          x       Minolta|KONICA ((MLY|KC|(\+M){4})|\001\000{5}\004)
    Nikon_1                 NIKON     (Nikon\000\001\000)
    Nikon_2                 NIKON     ()[^N] 
    Nikon_3       x         NIKON     (Nikon\000\002[\020\000]\000{2})
    Olympus                 OLYMPUS   (OLYMP\000[\001\002]\000) 
    Panasonic_1       x     Panasonic (Panasonic\000{3})
    Panasonic_2     x x     Panasonic (MKED)
    Pentax_1    x           Asahi     ()[^A]
    Pentax_2    x     x     Asahi     (AOC\000..)
    Ricoh_1         x       RICOH     (Rv|Rev)
    Ricoh_2         x       RICOH     (\000)
    Ricoh_3                 RICOH     ((Ricoh|RICOH)\000{3})
    Sanyo                   SANYO     (SANYO\000\001\000)
    Sigma                   SIGMA     (SIGMA\000{3}\001\000)
    Sony              x     SONY      (SONY (CAM|DSC) \000{3})
    Toshiba         x       TOSHIBA   ()
    unknown             x   .         ()


MakerNote format details are not usually released by vendors (well, this is an euphemism: no vendor ever, to my knowledge, released any detail on its format, exception made for Sigma/Foveon). All information used for this package was collected on the Internet (and its reliability is therefore limited) or through personal tests. Some interesting sites are (not an exhaustive list at all):

  Foveon:    Foveon is the same as Sigma, see Sigma
  Kodak:     my personal tests with my Kodak DX3900 (not IFD-like)

DX3900 MakerNote format

Kodak MakerNotes are written in a proprietary binary format, which is not IFD-like. So, there is no way to detect the beginning, end and type of a field; everything here was inferred through a careful comparison of the content of a set of Kodak JPEG files and their shot parameters. Fields seems to be aligned on four bytes boundaries. For the DX3900 model the endianness is always fixed to big endian. The signature regular expression is "^(KDK INFO[a-zA-Z0-9]* )", the maker is 'KODAK'. The meaning of the tags is as follows:

  BYTE   ???                firmware version? This is always 3
  BYTE   Compression        1 = normal, 2 = 2160x1440 high compression
  BYTE   BurstMode          0 = off,    1 = on
  BYTE   MacroMode          0 = normal, 1 = close-up
  SHORT  PixelXDimension    \ allowed     2160x1440, 1800x1200, 
  SHORT  PixelYDimension    /     values: 1536x1024, 1080x720
  SHORT  Year               the year value, with four digits
  BYTE   Month              the month value  (in [1,12])
  BYTE   Day                the day value    (in [1,31])
  BYTE   Hour               the hour value   (in [0,23])
  BYTE   Minute             the minute value (in [0,59])
  BYTE   Second             the second value (in [0,59])
  BYTE   SubSecond          (in 130th of seconds?)
  SHORT  ???                ???
  BYTE   ???                ???
  BYTE   ShutterMode        0 = auto, 32 = manual
  BYTE   MeteringMode       0 = multi-pattern, 1=centre weight., 2=centre spot
  BYTE   BurstSequenceIndex index in [1,8], 0 if burst mode off
  SHORT  FNumber            100 times the Exif F-number
  LONG   ExposureTime       in 10^-5 seconds
  SSHORT ExposureBiasValue  1000 times the exposure bias in [-2,+2 step .5]
  SHORT  ???                ???
  LONG   ???                \
  LONG   ???                 \ is this an estimate of the subject
  LONG   ???                 / distance? If so, it is very rough.
  LONG   ???                /
  BYTE   FocusMode          0 = auto, 2 = close, 3 = infinity
  BYTE   ???                always 2
  SHORT  ???                ???
  SSHORT PanoramaMode       0 = normal, -1 = focus at infinity
  SHORT  SubjectDistance    (x-28)*2.54+7 looks like the distance in cm
  BYTE   WhiteBalance       0 = normal, 1 = fluor., 2 = tungsten, 3 = daylight
  (27 bytes with unknown meaning here)
  BYTE   FlashMode          0 = auto, 1 = on, 2 = off, 3 = red-eyes
  BYTE   FlashFired         0 = yes,  1 = no
  SHORT  ISOSpeedMode       the requested speed in {100,200,400} or zero
  SHORT  ???                ???
  SHORT  TotalZoomFactor    100 times the zoom factor in [+1,+6 step 0.1]
  SHORT  DateTimeStampMode  0 = none, [1,6] = the six modes
  SHORT  ColourMode         1 = black & white, 2 = sepia, 32 = colour
  SHORT  DigitalZoomFactor  100 times the zoom factor in [+1,+3 step 0.1]
  BYTE   ???                always zero
  SBYTE  Sharpness          0 = standard, 1 = sharp, -1 = soft
  (808 bytes with unknown meaning here, maybe a thumbnail?)


Stefano Bettelli,


Copyright (C) 2004,2005,2006 by Stefano Bettelli

This library is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License. See the COPYING and LICENSE file for the license terms.


The main documentation page for the Image::MetaData::JPEG module.

2021-01-03 perl v5.32.0