NAME
exif - shows EXIF information in JPEG files
SYNOPSIS
exif [ OPTION ] [ file... ]
DESCRIPTION
exif is a small command-line utility to show and change EXIF
information in JPEG files.
Most digital cameras produce EXIF files, which are JPEG files with
extra tags that contain information about the image. The exif command-
line utility allows you to read EXIF information from and write EXIF
information to those files. exif internally uses the libexif library.
Each input file given on the command line is acted upon in turn, using
all the options given. Execution will be aborted immediately if one
file is not readable or does not contain EXIF tags.
As EXIF tags are read, any unknown ones are discarded and known ones
are automatically converted into the correct format, if they aren’t
already. Corrupted MakerNote tags are also removed, but no format
changes are made.
OPTIONS
-v, --version
Display the exif version number.
-i, --ids
Show ID numbers instead of tag names.
-t, --tag=TAG
Select only this TAG. TAG is the tag title, the short tag name,
or the tag number (hexadecimal numbers are prefixed with 0x),
from the IFD specified with --ifd. The tag title is dependent
on the current locale, whereas name and number are locale-
independent.
--ifd=IFD
Select a tag or tags from this IFD. Valid IFDs are "0", "1",
"EXIF", "GPS", and "Interoperability". Defaults to "0".
-l, --list-tags
List all known EXIF tags and IFDs. A JPEG image must be
provided, and those tags which appear in the file are shown with
an asterisk in the corresponding position in the list.
-|, --show-mnote
Show the contents of the MakerNote tag. The contents of this
tag are nonstandard (and often undocumented) and may therefore
not be recognized, or if they are recognized they may not
necessarily be interpreted correctly.
--remove
Remove the tag or (if no tag is specified) the entire IFD.
-s, --show-description
Show description of tag. The --tag option must also be given.
-e, --extract-thumbnail
Extract the thumbnail, writing the thumbnail image to the file
specified with --output.
-r, --remove-thumbnail
Remove the thumbnail from the image, writing the new image to
the file specified with --output.
-n, --insert-thumbnail=FILE
Insert FILE as thumbnail. No attempt is made to ensure that the
contents of FILE are in a valid thumbnail format.
--no-fixup
Do not attempt to fix EXIF specification violations when reading
tags. exif will remove illegal or unknown tags, add some
mandatory tags using default values, and change the data type of
tags to match that required by the specification.
-o, --output=FILE
Write output image to FILE. If this option is not given and an
image file must be written, the name used is the same as the
input file with the suffix ".modified.jpeg".
--set-value=VALUE
Set the data for the tag specified with --tag and --ifd to
VALUE. Compound values consisting of multiple components are
separated with spaces.
-c, --create-exif
Create EXIF data if it does not exist
-m, --machine-readable
Produce output in a machine-readable (tab-delimited) format.
The --xml-output and --machine-readable options are mutually
exclusive.
-w, --width=N
Set the maximum width of the output to N characters (default
80). This does not apply to some output formats (e.g. XML).
-x, --xml-output
Produce output in an XML format (when possible). The --xml-
output and --machine-readable options are mutually exclusive.
-d, --debug
Show debugging messages. Also, when processing a file that
contains corrupted data, this option causes exif to attempt to
continue processing. Normally, corrupted data causes an abort.
Help options
-?, --help
Show help message.
--usage
Display brief usage message.
EXAMPLES
Display all recognized EXIF tags in an image and the tag contents, with
bad tags fixed:
exif image.jpg
Display a table listing all known EXIF tags and whether each one exists
in the given image:
exif --list-tags --no-fixup image.jpg
Extract the thumbnail into the file thumbnail.jpg:
exif --extract-thumbnail --output=thumbnail.jpg image.jpg
Display a list of the numeric values of only the EXIF tags in the
thumbnail IFD (IFD 1) and the tag values:
exif --ids --ifd=1 --no-fixup image.jpg
Display the meaning of tag 0x9209 in the "EXIF" IFD according to the
EXIF specification:
exif --show-description --ifd=EXIF --tag=0x9209
Add an Orientation tag with value "bottom - left" to an existing image:
exif --output=new.jpg --ifd=0 --tag=0x0112 --set-value=4
--no-fixup image.jpg
Add a YCbCr Sub-Sampling tag with value 2,1 (a.k.a YCbCr 4:2:2) to an
existing image and fix the existing tags, if necessary:
exif --output=new.jpg --tag=YCbCrSubSampling --ifd=0
--set-value=’2 1’ image.jpg
AUTHOR
exif was written by Lutz Mueller <lutz@users.sourceforge.net> and
numerous contributors. This man page is Copyright © 2002-2009 Thomas
Pircher and others.
SEE ALSO
http://www.sourceforge.net/projects/libexif