README
1 libexif
2 -------
3
4DESCRIPTION
5-----------
6
7libexif is a library for parsing, editing, and saving EXIF data. It is
8intended to replace lots of redundant implementations in command-line
9utilities and programs with GUIs.
10
11
12FEATURES
13--------
14
15libexif supports parsing, editing and saving of EXIF data. In addition, it
16has gettext support. All EXIF tags described in EXIF standard 2.1 (and most
17from 2.2) are supported. Many maker notes from Canon, Casio, Epson,
18Fuji, Nikon, Olympus, Pentax and Sanyo cameras are also supported.
19
20
21REQUIREMENTS
22------------
23
24libexif is written in plain C and does not require any additional library.
25GNU gettext will be used for language translation, if available.
26
27
28LIMITATIONS
29-----------
30
31libexif can only handle some maker notes, and even those not very well. More
32work needs to be done. Note that libmnote has been merged with libexif - it
33is no longer needed.
34
35
36USAGE
37-----
38
39We have started documenting the libexif API using doxygen and are making
40the results available at http://libexif.sourceforge.net/api/
41
42Until someone writes some better documentation however, you need to refer
43to the header files.
44
45The short test-program test/test-mem illustrates how to create valid
46EXIF data from scratch, how to save EXIF data and how to load EXIF data
47from data in memory. There are also a few simple example programs available
48in the contrib/examples/ directory. Don't hesitate to contact us
49(<libexif-devel@lists.sourceforge.net>) if you've got any questions
50on how to use libexif.
51
52To link to libexif into your own package, we recommend using the
53pkgconfig utility (cf. http://pkg-config.freedesktop.org/wiki/). For
54your convenience, libexif both provides libexif-uninstalled.pc and
55installs libexif.pc.
56
57
58FRONTENDS
59---------
60
61Right now, I know of the following frontends to libexif:
62 - exif: A small command-line utility to show EXIF information in JPEG
63 files (http://www.sourceforge.net/projects/libexif).
64 - gexif: A GTK+ frontend for editing EXIF data
65 (http://www.sourceforge.net/projects/libexif).
66 - gphoto2: A command-line frontend to libgphoto2, a library to access a
67 wide range of digital cameras (http://www.gphoto.org).
68 - gtkam: A GTK+ frontend to libgphoto2 (http://www.topfrose.de).
69 - thirdeye: Digital photos organizer and driver for eComStation
70 (http://ecomstation.ru/thirdeye).
71 - digicam:
72If you would like to migrate your program to use libexif or add EXIF support
73to it, don't hesitate to contact the authors.
74
75
76LIBRARIES
77---------
78
79I know of the following libraries that use or have been inspired by libexif:
80 - libexif-gtk: library of widgets to help display EXIF tags in GTK
81 programs (part of the libexif project)
82 - pel: PHP-Code (http://pel.sourceforge.net)
83
84
85BUILDING
86--------
87
88It really depends on your environment what to do in order to get libexif
89to build. Building from the source tar ball usually involves the commands:
90
91 ./configure
92 make
93 sudo make install
94
95When building from source out of CVS, something like the following will be
96necessary:
97
98 gettextize
99 mv po/Makevars.template po/Makevars
100 aclocal -I auto-m4 -I m4m
101 autoheader
102 libtoolize --force
103 automake --add-missing
104 autoconf
105 ./configure
106 make
107
108Or, possibly just:
109
110 autoreconf -i
111 ./configure
112 make
113
114Besides the standard arguments, configure takes several specific to libexif:
115
116 --disable-docs To disable producing any documentation
117 --enable-internal-docs Build internal code docs if Doxygen available
118 --enable-ship-binaries To include Windows DLLs in 'make dist'
119
120Certain specialized applications can reduce the size of the libexif
121binary by setting one or both of the following macros in the CPPFLAGS
122environment variable at configure time. Each one removes certain kinds of
123text strings and constants from the binary. Applications which need
124to access specific, known EXIF tags and know in advance the meaning of
125their data have no need of those strings and can save considerable space
126by eliminating them.
127
128 -DNO_VERBOSE_TAG_STRINGS Names and descriptions of EXIF tags, debug messages,
129 mandatory EXIF fields (disabling auto-tag-fixup)
130 -DNO_VERBOSE_TAG_DATA Names of enumerated tag data contents
131
132
133INTERNATIONALIZATION
134--------------------
135
136The libexif translations are made by volunteers working on their own,
137either directly with the libexif project or through one of two translation
138coordination sites, the Translation Project
139<http://translationproject.org/domain/libexif.html> and Launchpad
140<https://translations.edge.launchpad.net/ubuntu/karmic/+source/libexif>.
141Any updates to language translations coordinated by the Translation Project
142must be made through their web site, but all other languages can be
143updated either through Launchpad (preferred) or by sending updates to
144the libexif developers mailing list directly. As of this writing, the
145following languages must be updated through the Translation Project:
146da de es fr nl pl sk sv vi
147
148If you are interested in translating libexif into a new language, we
149recommend that you join one of the above translation groups and take
150advantage of the systems they have built to help you. A translation
151disclaimer is NOT required for libexif at the Translation Project; by making
152a translation, you agree implicitly to provide it under the same license
153terms as the rest of libexif (LGPL).
154
155
156AUTHORS
157-------
158
159libexif has originally been written by Curtis Galloway
160<curtisg@users.sourceforge.net>. Because of the original design not
161supporting editing and saving, Lutz Mueller <lutz@users.sourceforge.net>
162rewrote libexif from scratch.
163
164
165LINKS
166-----
167
168Some links you might want to check out if you are interested in further
169information about EXIF.
170
171 - http://drewnoakes.com/code/exif: metadata extraction framework in Java
172 - http://www.pima.net: This is where I got the exif standard from. Site is
173 down as of 2002/12/31.
174 - http://www.jeida.or.jp: Can't remember any more. Site is down as of
175 2002/12/31.
176 - http://www.exif.org: information about the EXIF standard.
177 - http://www.sno.phy.queensu.ca/~phil/exiftool/TagNames/index.html: Looks
178 like libexif in Perl. Seems to support a lot of MakerNotes.
179