The Image::ExifTool Perl Library Module
Description
The Image::ExifTool library provides an extensible set of perl modules to read and
write meta information in a wide variety of image, audio and video files.
Index
The following sections of this document give examples of how to use Image::ExifTool,
and explain the following individual functions in more detail:
The ExifTool module may be used by simply calling the
ImageInfo function:
use Image::ExifTool qw(ImageInfo);
my $info = ImageInfo('image.jpg');
|
or in a more object-oriented fashion, by creating an ExifTool object:
use Image::ExifTool;
my $exifTool = new Image::ExifTool;
my $info = $exifTool->ImageInfo('image.jpg');
|
The object-oriented method allows more flexibility, but is slightly more
complicated. You choose the method that you prefer.
The $info value returned by ImageInfo in the above
examples is a reference to a hash containing the tag/value pairs. Here is a
simplified example which prints out this information:
foreach (keys %$info) {
print "$_ => $$info{$_}\n";
}
|
See the ImageInfo section for a more detailed
description of the info hash entries.
And here is an example of how to write information:
use Image::ExifTool;
my $exifTool = new Image::ExifTool;
$exifTool->SetNewValue(Author => 'Phil Harvey');
$exifTool->WriteInfo('image.jpg','modified_image.jpg');
|
Obtain meta information from image. This is the one-step function for obtaining
meta information from an image. Internally, ImageInfo
calls ExtractInfo to extract data from the image, and
GetInfo and GetTagList to
generate the returned information hash and tag list.
| Prototype | ImageInfo($;@) |
| Inputs | 0) [optional] ExifTool object reference
1) File name, file reference or scalar reference
2-N) [optional] list of tag names to find (or tag list reference or
options reference, see below)
|
| Returns | Hash reference for tag/value pairs |
Examples:
Non object-oriented example showing use of options and returning tag list:
use Image::ExifTool qw(ImageInfo);
my @ioTagList;
my $info;
$info = ImageInfo('image.jpg', \@ioTagList, {Sort => 'Group0'});
|
Object-oriented example to read from a file that is already open:
my $exifTool = new Image::ExifTool;
$info = $exifTool->ImageInfo(\*FILE_PT, 'Aperture', 'ShutterSpeed', 'ISO');
|
Extract information from an image in memory:
$info = $exifTool->ImageInfo(\$imageData);
|
Extract information from an embedded thumbnail image:
$info = ImageInfo('image.jpg', 'thumbnailimage');
my $thumbInfo = ImageInfo($$info{ThumbnailImage});
|
Using an ExifTool object to set the options before calling
ImageInfo:
my $filename = shift || die "Please specify filename\n";
my @ioTagList = ('DateTimeOriginal', 'ImageSize', 'FocalLength');
$exifTool->Options(Unknown => 1, DateFormat => '%H:%M:%S %a. %b. %e, %Y');
$info = $exifTool->ImageInfo($filename, \@ioTagList);
|
Function Arguments:
ImageInfo is very flexible about the arguments
passed to it, and interprets them based on their type. It may be called with
one or more arguments. The one required argument is either a SCALAR (the image
file name), a file reference (a reference to the image file) or a SCALAR
reference (a reference to the image in memory). Other arguments are optional.
The order of the arguments is not significant, except that the first SCALAR is
taken to be the file name unless a file reference or scalar reference comes
earlier in the argument list.
Below is a more detailed explanation of how the ImageInfo
function arguments are interpreted.
ExifTool ref --
ImageInfo may be called with an ExifTool object if
desired. The advantage of using the object-oriented form of this function is
that after ImageInfo returns, you may use the
object-oriented functions below to obtain additional information if required.
Must be the first argument if used.
SCALAR --
The first scalar argument is taken to be the file name unless an earlier
argument specified the image data via a file reference (file ref) or data
reference (SCALAR ref). The remaining scalar arguments are names of tags for
requested information. If no tags are specified, all possible information
is extracted. Tag names may begin with '-' indicating tags to exclude. The
tag names are case-insensitive, so note that the returned tags may not be
exactly the same as the requested tags. For this reason it is best to use
either the keys of the returned hash or the elements of the tag array when
accessing the return values
File ref --
A reference to an open image file. If you use this method (or a SCALAR
reference) to access information in an image, the FileName and Directory tags
will not be returned. (Also, the FileSize and FileModifyDate tags will not be
returned unless it is a plain file.)
SCALAR ref --
A reference to image data in memory.
ARRAY ref --
Reference to a list of tag names. On entry, any elements in the
list are added to the list of requested tags. On return, this list
is updated to contain a sorted list of tag names in the proper case.
HASH ref --
Reference to a hash containing the options settings. See
Options documentation below for a list of available
options. Options specified as arguments to ImageInfo
take precedence over Options settings.
Return Value:
ImageInfo returns a reference to a hash of tag/value pairs. The keys of the
hash are the tag identifiers, which are similar to the tag names but my have an
embedded copy number if more than one tag with that name was found in the image.
Use GetTagName to remove the copy number from the
tag. Note that the case of the tags may not be the same as requested.
Values of the returned hash are usually simple scalars, but a scalar
reference is used to indicate binary data and an array reference may be used
to indicate a list. Lists of values are joined by commas into a single
string if and only if the PrintConv option is enabled and the List option is
disabled (which are the defaults). Note that binary values are not
necessarily extracted unless specifically requested or the Binary option is
set. If not extracted the value is a reference to a string of the form
"Binary data ##### bytes".
Here is a simple example to print out the information returned by
ImageInfo. It shows how to print out a human-friendly
output for all returned tag values, and works for either setting of the
PrintConv option (although binary data will be printed to the console if
PrintConv is disabled):
foreach (keys %$info) {
my $val = $$info{$_};
if (ref $val eq 'ARRAY') {
$val = join(', ', @$val);
} elsif (ref $val eq 'SCALAR') {
$val = '(Binary data)';
}
printf("%-24s : %s\n", $_, $val);
}
|
and gives output like this (PrintConv enabled):
WhiteBalance : Auto
FNumber : 3.5
InteroperabilityOffset : 936
XResolution : 72
ISO : 100
ThumbnailImage : (Binary data)
FlashOn : On
Make : FUJIFILM
ShutterSpeedValue : 1/64
ExposureCompensation : 0
Sharpness : Soft
ResolutionUnit : inches
|
Notes:
As well as tags representing information extracted from the image,
the following tags generated by ExifTool may be returned:
| ExifToolVersion | The ExifTool version number |
| Error | An error message if the image could not be read |
| Warning | A warning message if problems were encountered
while extracting information |
Create a new ExifTool object.
Example:
my $exifTool = new Image::ExifTool;
|
Note that ExifTool uses AUTOLOAD to load non-member methods, so any class
using Image::ExifTool as a base class must define an AUTOLOAD which calls
Image::ExifTool::DoAutoLoad(). ie)
sub AUTOLOAD
{
Image::ExifTool::DoAutoLoad($AUTOLOAD, @_);
}
|
|
The following functions require an ExifTool object as the first argument
|
Get/set ExifTool options. This function can be called to set the default
options for an ExifTool object. Options set this way are in effect for
all function calls but may be overridden by options passed as arguments
to a specific function.
| Prototype | Options($$;@) |
| Inputs | 0) ExifTool object reference
1) Parameter name (see table below)
2) [optional] Option value if specified
3-N) [optional] Additional parameter/value pairs
|
| Returns | Previous value of last specified parameter |
Available options:
| ExifTool Options |
|---|
| Option | Description | Values | Default |
|---|
| Binary | Flag to extract the value data for all binary tags.
Tag values representing large binary data blocks (ie. ThumbnailImage)
are not necessarily extracted unless this option is set or the tag is
specifically requested by name. |
0 or 1 | 0 |
| ByteOrder | The byte order for newly created EXIF segments when writing.
If EXIF information already exists, the existing order is used instead. If not
defined, the order of the maker notes is used (if maker notes are copied), otherwise
it defaults to 'MM'. |
'MM','II' or undef | undef |
| Charset | Character set for converting 16-bit Unicode character strings. |
| UTF8 - | UTF-8 characters |
| Latin - | Windows Latin1 (cp1252) |
| 'UTF8' |
| Compact | Write compact output. The XMP specification suggests that
the data be padded with blanks to allow in-place editing. By setting this
flag, 2kB is saved for files with XMP data. | 0 or 1 | 0 |
| Composite | Flag to calculate Composite tags | 0 or 1 | 1 |
| CoordFormat | Format for GPS coordinates | Format for
printing GPS coordinates. This is a printf format string with specifiers
for degrees, minutes and seconds in that order, however minutes and seconds
may be omitted. The default is equivalent to using a format string of
q{%d deg %d' %.2f"}.
| undef |
| DateFormat | Format for date/time | See strftime manpage for details |
undef |
| Duplicates | Flag to save duplicate tag values | 0 or 1 | 1 |
| Exclude |
Exclude specified tags |
Tag name or reference to a list of tag names to exclude. Case is not significant.
Tags may also be excluded by preceeding their name with a '-' in the arguments to ImageInfo. |
undef |
| FixBase |
Fix maker notes base offset. Allows values to be extracted from maker notes
which have been corrupted by editing with 3rd party software. |
An integer specifying a value to be added to the maker notes base offset, or the
empty string ('') for ExifTool to take its best guess at the correct base. |
undef |
| Group# | Extract tags for specified groups |
Group name or reference to list of group names.
Group name may begin with '-' to exclude a group. Case IS significant.
See GetAllGroups for a list of available groups. |
undef |
| HtmlDump | Dump information in hex to a dynamic HTML web page.
Option value sets a limit on the maximum block size. Output file is
specified by the TextOut option. |
| 0 = | No HTML dump |
| 1 = | 1 KB size limit |
| 2 = | 16 KB size limit |
| 2 = | Full dump |
| 0 |
| IgnoreMinorErrors | Causes some minor errors to be ignored.
This option is provided mainly to allow writing of files when minor errors
occur, but also allows thumbnail and preview images to be extracted even if
they don't have a recognizable header. |
0 or 1 | 0 |
| List | Flag to extract lists of PrintConv values into arrays instead of concatenating
them into comma-separated strings. | 0 or 1 | 0 |
| MakerNotes | Flag to cause MakerNotes data and other writable subdirectories
(such as PrintIM) to be extracted as a data block. |
0 or 1 | 0 |
| PrintConv | Flag to enable print conversion. Also enables inverse print
conversion for writing. | 0 or 1 | 1 |
| Sort | Specifies order to sort tags in the returned tag list |
| Input | Sort in same order as input tag arguments |
| Alpha | Sort alphabetically |
| File | Sort in order that tags were found in the file |
| Group# | Sort by tag group,
where # is the group family number. If # is not specified, Group0 is assumed.
See GetAllGroups for a group list. |
| 'Input' |
| TextOut | Output file for Verbose and HtmlDump options. |
File reference | \*STDOUT |
| Unknown | Flag to get values of unknown tags |
| 0 = | Unknown tags not extracted |
| 1 = | Unknown tags extracted from EXIF directories |
| 2 = | Unknown tags also extracted from binary data blocks |
| 0 |
| Verbose | Print verbose messages to file specified by TextOut option.
Click here for example outputs. |
| 0 = | No verbose messages |
| 1 = | Print tag names and raw values |
| 2 = | Add additional tag details |
| 3 = | Add hex dump of tag data (with length limits) |
| 4 = | Remove length limit on dump of tag values |
| 5 = | Remove length limit on dump of JPEG segments |
| 0 |
Examples:
$exifTool->Options(Exclude => 'OwnerName');
|
$exifTool->Options(Group0 => ['EXIF', 'MakerNotes']);
|
$exifTool->Options(Group1 => '-IFD1'); # ignore IFD1 tags
|
$exifTool->Options(Sort => 'Group2', Unknown => 1);
|
my $oldSetting = $exifTool->Options(Duplicates => 0);
|
my $isVerbose = $exifTool->Options('Verbose');
|
Reset all options to their default values.
| Prototype | ClearOptions() |
| Inputs | 0) ExifTool object reference
|
Extract all meta information from an image.
| Prototype | ExtractInfo($;@) |
| Inputs | 0) ExifTool object reference
1-N) Same as ImageInfo except that a list of tags is
not returned if an ARRAY reference is given.
|
| Returns | 1 if this was a valid image, 0 otherwise |
The following options are effective in the call to ExtractInfo:
Binary, Composite, DateFormat, Unknown and Verbose.
Example:
$success = $exifTool->ExtractInfo('image.jpg', \%options);
|
GetInfo is called to return meta information
after it has been extracted from the image by a previous call to
ExtractInfo or ImageInfo.
This function may be called repeatedly after a single call to
ExtractInfo or ImageInfo.
| Prototype | GetInfo($;@) |
| Inputs | 0) ExifTool object reference
1-N) Same as ImageInfo except that an image
can not be specified
|
| Returns | Reference to information hash, the same as with
ImageInfo |
Examples:
$info = $exifTool->GetInfo('ImageWidth', 'ImageHeight');
|
$info = $exifTool->GetInfo(\@ioTagList);
|
$info = $exifTool->GetInfo({Group2 => ['Author', 'Location']});
|
The following options are effective in the call to GetInfo:
Duplicates, Exclude, Group#, PrintConv (and Sort if tag list reference is given).
Write meta information to a file. The specified source file is rewritten to the
same-type destination file with new information as specified by previous calls
to SetNewValue. The necessary segments and/or
directories are created in the destination file as required to store the
specified information. May be called repeatedly to write the same information
to additional files without the need to call
SetNewValue again.
| Prototype | WriteInfo($$;$$) |
| Inputs | 0) ExifTool object reference
1) Source file name, file reference, or scalar reference
2) [optional] Destination file name, file or scalar reference
3) [optional] Destination file type
|
| Returns | 1 if file was written OK, 2 if file was written
but no changes made, 0 on file write error.
|
The source file name may be undefined to create a file from scratch
(currently only .XMP files can be created in this way). If undefined, the
destination file type is required unless the type can be determined from the
destination file name.
The destination file name may be undefined to edit a file in place (make
sure you have backups!). If a destination file name is given, the specified
file must not exist because existing destination files will not be
overwritten.
The destination file type is only used if the source file is undefined.
Examples:
# add information to a source file, writing output to new file
my $result = $exifTool->WriteInfo($srcfile, $dstfile);
# create XMP data file from scratch
$exifTool->WriteInfo(undef, $dstfile, 'XMP');
# edit file in place (you do have backups, right?)
$exifTool->WriteInfo($srcfile);
# retrieve error and warning messages
$errorMessage = $exifTool->GetValue('Error');
$warningMessage = $exifTool->GetValue('Warning');
|
If an error code is returned, an Error tag is set and GetValue('Error') can
be called to obtain the error description. A Warning tag mag be set even if
this routine is successful.
Combine information from more than one information hash into a single hash.
| Prototype | CombineInfo($;@) |
| Inputs | 0) ExifTool object reference
1-N) List of info hash references
|
| Returns | Reference to combined information hash |
Example:
$info = $exifTool->CombineInfo($info1, $info2, $info3);
|
If the Duplicates option is disabled and duplicate tags exist, the order of
the hashes is significant. In this case, the value used is the first value
found as the hashes are scanned in order of input. The Duplicates option
is the only option that is in effect for this function.
Get a sorted list of tags from the specified information hash or tag list.
| Prototype | GetTagList($;$$) |
| Inputs | 0) ExifTool object reference
1) [optional] Reference to info hash or tag list
2) [optional] Sort order ('File', 'Input', 'Alpha' or 'Group#')
|
| Returns | List of tags in specified order |
Example:
@tags = $exifTool->GetTagList($info, 'Group0');
|
If the information hash or tag list reference is not provided, then the list
of found tags from the last call to ImageInfo,
ExtractInfo or GetInfo
is used instead, and the result is the same as if
GetFoundTags was called. If sort order is not
specified, the sort order is taken from the current options settings.
Get list of found tags in specified sort order. The found tags are the
tags for the information obtained from the most recent call to
ImageInfo, ExtractInfo
or GetInfo for this object.
| Prototype | GetFoundTags($;$) |
| Inputs | 0) ExifTool object reference
1) [optional] Sort order ('File', 'Input', 'Alpha' or 'Group#')
|
| Returns | List of tags in specified order |
Example:
my @tags = $exifTool->GetFoundTags('File');
|
Get list of requested tags. These are the tags that were specified
in the arguments of the most recent call to ImageInfo,
ExtractInfo or GetInfo,
including tags specified via a tag list reference. They are returned
in the same order that they were specified. Shortcut tags are expanded
in the list.
| Prototype | GetRequestedTags($) |
| Inputs | 0) ExifTool object reference
|
| Returns | List of requested tags (empty if no tags
specifically requested) |
Example:
my @requestedTags = $exifTool->GetRequestedTags();
|
Get the value of a specified tag. The returned value is either the
human-readable (PrintConv) value, the converted machine-readable (ValueConv)
value, or the original raw (Raw) value. If the value type is not specified,
the PrintConv value is returned if the PrintConv option is set, otherwise
the ValueConv value is returned.
In the case of a list (as can happen with the 'Keywords' tag for
instance), PrintConv returns a comma-separated string of values in scalar
context, while ValueConv returns a reference to an array of values.
GetValue always returns the list itself in list
context. The PrintConv values are the values returned by
ImageInfo and GetInfo in the
tag/value hash unless the PrintConv option is disabled.
| Prototype | GetValue($$;$) |
| Inputs | 0) ExifTool object reference
1) Tag key
2) [optional] Value type, 'PrintConv', 'ValueConv', 'Both' or 'Raw'
The default value type is 'PrintConv' if the PrintConv option is set,
otherwise the default is 'ValueConv'. A value type of 'Both' returns
both ValueConv and PrintConv values as a list.
|
| Returns |
The value of the specified tag. If the tag represents a list of values and
the List option is disabled then PrintConv returns a comma separated string
of values, otherwise a reference to the list is returned in scalar context.
The list itself is returned in list context. Values may also be scalar
references to binary data.
Note: It is possible for GetValue to return an
undefined ValueConv or PrintConv value (or an empty list in list context)
even if the tag exists, since it is possible for these conversions to yield
undefined values.
|
Examples:
# PrintConv example
my $val = $exifTool->GetValue($tag);
if (ref $val eq 'SCALAR') {
print "$tag = (unprintable value)\n";
} else {
print "$tag = $val\n";
}
# ValueConv examples
my $val = $exifTool->GetValue($tag, 'ValueConv');
if (ref $val eq 'ARRAY') {
print "$tag is a list of values\n";
} elsif (ref $val eq 'SCALAR') {
print "$tag represents binary data\n";
} else {
print "$tag is a simple scalar\n";
}
my @keywords = $exifTool->GetValue('Keywords', 'ValueConv');
|
Set the new value for a tag. The routine may be called multiple times to set
the values of many tags before using WriteInfo to write
the new values to an image.
For list-type tags (like Keywords), either call repeatedly with the same tag
name for each value, or call with a reference to the list of values.
| Prototype | SetNewValue($;$$$) |
| Inputs | 0) ExifTool object reference
1) [optional] Tag key or tag name, or undefined to clear all new values.
A tag name of '*' can be used when deleting tags to delete all tags, or all
tags in a specified group. The tag name may be prefixed by group name,
separated by a colon (ie. 'GROUP:TAG'), which is equivalent to using a
'Group' option argument.
2) [optional] New value for tag. Undefined to delete tag from file.
May be a scalar, scalar reference, or list reference to set a list
of values.
3-N) [optional] SetNewValue options hash entries (see below).
|
| Returns | Scalar context: The number of tags set, and
errors are printed to STDERR.
List context: The number of tags set and the error string.
|
| SetNewValue Options |
|---|
| Option | Description | Values | Default |
|---|
| Type | The type of value being set |
PrintConv, ValueConv or Raw (default depends on PrintConv Option) |
PrintConv or ValueConv |
| AddValue | Add value to existing list rather than
replacing the list | 0 or 1 | 0 |
| DelValue | Delete an existing tag if it has the specified value |
0 or 1 | 0 |
| Group | Specifies group name where tag should be written.
If not specified, tag is written to hightest priority group as specified
by SetNewGroups. Case is not significant |
Any family 0 or 1 group name | undef |
| NoShortcut | Disables default behaviour of looking up tag in
shortcuts if not found otherwise. | 0 or 1 | 0 |
| Protected | Allow protected tags to be written |
Bitmask of tag protection levels to write:
| 0 |
| Replace | Replace previous new value for this tag (ie. replace the value
set in a previous call to SetNewValue) |
| 0 = | Don't replace |
| 1 = | Replace with specified new value |
| 2 = | Reset previous new value only |
| 0 |
| Shift | Shift the tag by the specified value. Currently only date/time
tags can be shifted. Value is added if Shift is 1, or subtracted if Shift is -1.
See Image::ExifTool::Shift.pl for details time shift formats. |
| undef = No shift |
| 0 = | Shift if shiftable:
1 if AddValue set
-1 if DelValue set |
| 1 = | Positive shift |
| -1 = | Negative shift |
| undef |
Examples:
# set a new value for a tag (errors go to STDERR)
$success = $exifTool->SetNewValue($tag, $value);
# set a new value and capture any error message
($success, $errStr) = $exifTool->SetNewValue($tag, $value);
# delete information for specified tag if it exists in image
# (also resets AddValue and DelValue options for this tag)
$exifTool->SetNewValue($tag);
# reset all values from previous calls to SetNewValue()
$exifTool->SetNewValue();
# delete a specific keyword
$exifTool->SetNewValue('Keywords', $word, DelValue => 1);
# write a list of keywords
$exifTool->SetNewValue('Keywords', ['word1','word2']);
# add a keyword without replacing existing keywords
$exifTool->SetNewValue(Keywords => $word, AddValue => 1);
# set a tag in a specific group
$exifTool->SetNewValue(Headline => $val, Group => 'XMP');
# shift original date/time back by 1 hour
$exifTool->SetNewValue(DateTimeOriginal => '1:00', Shift => -1);
|
A very powerful routine that sets new values for tags from information found
in a specified file.
| Prototype | SetNewValuesFromFile($$;@) |
| Inputs | 0) ExifTool object reference
1) File name, file reference, or scalar reference
2-N) [optional] List of tag names to set. All writable tags are set if
none are specified. The tag names are not case sensitive, and may be prefixed
by an optional family 0 or 1 group name, separated by a colon (ie. 'exif:iso').
A leading '-' indicates tags to be excuded (ie. '-comment'). An asterisk ('*')
may be used for the tag name, and is useful when a group is specified to set
all tags from a group (ie. 'XMP:*'). A special feature allows tag names of the
form 'SRCTAG>DSTTAG' (or 'DSTTAG<SRCTAG') to be specified to copy
information to a tag with a different name or a specified group. Both 'SRCTAG'
and 'DSTTAG' may use '*' and/or be prefixed by a group name (ie.
'modifyDate>fileModifyDate' or '*>xmp:*'). Tags are evaluated in order,
so exclusions apply only to tags included earlier in the list.
|
| Returns | A hash of information that was set
successfully. May include Warning or Error entries if there were problems
reading the input file.
|
By default, this routine will commute information between same-named tags in
different groups, allowing information to be translated between images with
different formats. This behaviour may be modified by specifying a group name
for extracted tags (even if '*' is used as a group name), in which case the
information is written to the original group, unless redirected to a different
group. (For example, a tag name of '*:*' may be specified to copy all
information while preserving the original groups.)
Examples:
# set new values from all information in a file...
my $info = $exifTool->SetNewValuesFromFile($srcFile);
# ...then write these values to another image
my $result = $exifTool->WriteInfo($file2, $outFile);
# set all new values, preserving original groups
$exifTool->SetNewValuesFromFile($srcFile, '*:*');
# set specific information
$exifTool->SetNewValuesFromFile($srcFile, $tag1, $tag2...);
# set new value from a different tag in specific group
$exifTool->SetNewValuesFromFile($src, 'IPTC:Keywords>XMP-dc:Subject');
|
Notes:
The PrintConv option applies to this routine, but it should normally be left
on to provide more reliable transfer of information between groups.
If a preview image exists, it is not copied. The preview image must be
transferred separately if desired.
When simply copying all information between files of the same type, it is
usually desireable to preserve the original groups by specifying '*:*' for
the tags to set.
Get list of new Raw values for the specified tag. These are the values
that will be written to file. Only tags which support a 'List' may return
more than one value.
| Prototype | GetNewValues($$) |
| Inputs | 0) ExifTool object reference
1) Tag key or tag name
|
| Returns | List of new Raw tag values.
The list may be empty if the tag is being deleted
(ie. if SetNewValue was called without a value).
|
Examples:
my $rawVal = $exifTool->GetNewValues($tag);
my @rawVals = $exifTool->GetNewValues($tag);
|
Return the total number of new values set.
| Prototype | CountNewValues($) |
| Inputs | 0) ExifTool object reference
|
| Returns | The total number of tags with new values set.
|
Examples:
my $numSet = $exifTool->CountNewValues();
|
Save state of new values to be later restored by RestoreNewValues.
| Prototype | SaveNewValues($) |
| Inputs | 0) ExifTool object reference
|
Example:
$exifTool->SaveNewValues(); # save state of new values
$exifTool->SetNewValue(ISO => 100); # set new value for ISO
$exifTool->WriteInfo($src, $dst1); # write ISO plus any previous new values
$exifTool->RestoreNewValues(); # restore previous new values
$exifTool->WriteInfo($src, $dst2); # write previous new values only
|
Restore new values to the settings that existed when
SaveNewValues was last called. May be called
repeatedly after a single call to SaveNewValues.
See SaveNewValues above for an example.
| Prototype | RestoreNewValues($) |
| Inputs | 0) ExifTool object reference
|
Set the file modification time from the new value of the FileModifyDate tag.
| Prototype | SetFileModifyDate($$;$) |
| Inputs | 0) ExifTool object reference
1) File name
2) [optional] Base time if applying shift (in days before $^T)
|
| Returns | 1 if the time was changed, 0 if the FileModifyDate
tag wasn't set, or -1 if there was an error setting the time.
|
Example:
my $result = $exifTool->SetFileModifyDate($file);
|
Set the order of the preferred groups when adding new information. In
subsequent calls to SetNewValue, new information will
be created in the first valid group of this list. This has an impact only if
the group is not specified and the tag name exists in more than one group. The
default order is EXIF, GPS, IPTC, XMP and MakerNotes. Any family 0 group name
may be used. Case is not significant.
| Prototype | SetNewGroups($;@) |
| Inputs | 0) ExifTool object reference
1-N) Groups in order of priority. If no groups are specified, the
priorities are reset to the defaults.
|
Examples:
$exifTool->SetNewGroups('XMP','EXIF','IPTC');
|
Get current group priority list.
| Prototype | GetNewGroups($) |
| Inputs | 0) ExifTool object reference
|
| Returns | List of group names in order of write
priority. Highest priority first.
|
Examples:
@groups = $exifTool->GetNewGroups();
|
Get the ID for the specified tag. The ID is the IFD tag number in EXIF
information, the property name in XMP information, or the data offset in a
binary data block. For some tags, such as Composite tags where there is no ID,
an empty string is returned.
| Prototype | GetTagID($$) |
| Inputs | 0) ExifTool object reference
1) Tag key
|
| Returns | Tag ID or '' of there is no ID for this tag |
Example:
my $id = $exifTool->GetTagID($tag);
|
Get description for specified tag. This function will always return a defined
value. In the case where the description doesn't exist, the tag name is returned.
| Prototype | GetDescription($$) |
| Inputs | 0) ExifTool object reference
1) Tag key
|
| Returns | Tag description |
Get group name for specified tag.
| Prototype | GetGroup($$;$) |
| Inputs | 0) ExifTool object reference
1) Tag key
2) [optional] Group family number
|
| Returns | Group name (or 'Other' if tag has no
group). If no group family is specified, returns the name of group in family 0
when called in scalar context, or the names of groups for all families in list
context. See GetAllGroups for a list of group
names.
|
Example:
my $group = $exifTool->GetGroup($tag, 0);
|
Get list of group names for all tags in specified information hash.
| Prototype | GetGroups($;$$) |
| Inputs | 0) ExifTool object reference
1) [optional] Information hash reference (default is all extracted info)
2) [optional] Group family number (default 0)
|
| Returns |
List of group names in alphabetical order.
If information hash is not specified, the group names are returned for
all extracted information. See GetAllGroups for
a complete list of group names.
|
Examples:
my @groups = $exifTool->GetGroups($info, $family);
|
Example of one way to print information organized by group
my $exifTool = new Image::ExifTool;
$exifTool->ExtractInfo('t/images/ExifTool.jpg');
my $family = 1;
my @groups = $exifTool->GetGroups($family);
my $group;
foreach $group (@groups) {
print "---- $group ----\n";
my $info = $exifTool->GetInfo({"Group$family" => $group});
foreach ($exifTool->GetTagList($info)) {
print "$_ : $$info{$_}\n";
}
}
|
Builds composite tags from required tags. The composite tags are convenience
tags which are derived from the values of other tags. This routine is called
automatically by ImageInfo if the Composite option is set.
| Prototype | BuildCompositeTags($) |
| Inputs | 0) ExifTool object reference
|
| Returns | (none) |
Notes:
- Tag values are calculated in alphabetical order unless a tag Require's
or Desire's another composite tag, in which case the calculation is
deferred until after the other tag is calculated.
- Composite tags may need to read data from the image for their value to be
determined, so for these BuildCompositeTags
must be called while the image is available. This is only a problem if
ImageInfo is called with a filename (as opposed to a
file reference or scalar reference) since in this case the file is closed before
ImageInfo returns. However if you enable the Composite
option, BuildCompositeTags is called from
within ImageInfo before the file is closed.
|
The following functions access only static data and are not called with an
ExifTool object
|
Get name of tag from tag identifier. This is a convenience function that
strips the embedded copy number, if it exists, from the tag key.
| Prototype | GetTagName($) |
| Inputs | 0) Tag key
|
| Returns | Tag name |
Example:
$tagName = Image::ExifTool::GetTagName($tag);
|
Get list of tag shortcut names.
| Prototype | GetShortcuts() |
| Inputs | (none)
|
| Returns | List of shortcuts |
Get list of all available tag names.
| Prototype | GetAllTags(;$) |
| Inputs | 0) [optional] Group name
|
| Returns | A list of all available tags in alphabetical
order, or all tags in specified group. The group name is case insensitive,
and any group in any family may be used except for EXIF family 1 groups (ie.
the specific IFD).
|
Get list of all writable tag names.
| Prototype | GetWritableTags(;$) |
| Inputs | 0) [optional] Group name
|
| Returns | A list of all writable tags in alphabetical
order. These are the tags for which values may be set through
SetNewValue. If a group name is given, returns
only writable tags in specified group. The group name is case insensitive,
and any group in any family may be used except for EXIF family 1 groups (ie.
the specific IFD).
|
Get list of all group names in specified family.
| Prototype | GetAllGroups($) |
| Inputs | 0) Group family number (0-2)
|
| Returns |
A list of all groups in the specified family in alphabetical order |
Three families of groups are currently defined: 0, 1 and 2. Families 0 and 1
are based on the file structure, and family 2 classifies information based
on the logical category to which the information refers.
Families 0 and 1 are similar except that family 1 is more specific, and
sub-divides the EXIF, MakerNotes, XMP and ICC_Profile groups to give more
detail about the specific location where the information was found. The
EXIF group is split up based on the specific IFD (Image File Directory), the
MakerNotes group is divided into groups for each manufacturer, and the XMP
group is separated based on the XMP namespace prefix. Note that only common
XMP namespaces are listed below but additional namespaces may be present in
some XMP data. Also note that the 'XMP-xmp...' group names may appear in
the older form 'XMP-xap...' since these names evolved as the XMP standard
was developed. The ICC_Profile group is broken down to give information
about the specific ICC_Profile tag from which multiple values were
extracted. As well, information extracted from the ICC_Profile header is
separated into the ICC-header group.
Here is a complete list of groups for each family:
| Family | Group Names |
|---|
| 0 (General Location) |
AFCP, AIFF, APP12, ASF, BMP, Composite, DICOM, DNG, EXIF, ExifTool, File,
GPS, GeoTiff, ICC_Profile, ID3, IPTC, JFIF, Jpeg2000, Leaf, MIFF, MNG,
MakerNotes, Meta, PDF, PICT, PNG, Photoshop, PostScript, PrintIM, QuickTime,
RIFF, SigmaRaw, XMP
|
| 1 (Specific Location) |
AFCP, AIFF, APP12, ASF, BMP, Canon, CanonCustom, CanonRaw, Casio, Composite,
DICOM, DNG, ExifIFD, ExifTool, File, FujiFilm, GPS, GeoTiff, GlobParamIFD,
ICC-chrm, ICC-clrt, ICC-header, ICC-meas, ICC-view, ICC_Profile, ID3, ID3v1,
ID3v2_2, ID3v2_3, ID3v2_4, IFD0, IFD1, IPTC, InteropIFD, JFIF, JVC,
Jpeg2000, Kodak, KodakBordersIFD, KodakEffectsIFD, KyoceraRaw, Leaf,
LeafSubIFD, MIFF, MNG, MakerUnknown, MetaIFD, Minolta, Nikon, NikonCapture,
NikonPreview, Olympus, PDF, PICT, PNG, Panasonic, Pentax, Photoshop,
PostScript, PrintIM, QuickTime, RIFF, Ricoh, SR2, SRF#, Sanyo, Sigma,
SigmaRaw, Sony, SubIFD, Track#, XMP, XMP-PixelLive, XMP-aux, XMP-cc,
XMP-crs, XMP-dc, XMP-dex, XMP-exif, XMP-iptcCore, XMP-pdf, XMP-photoshop,
XMP-tiff, XMP-xmp, XMP-xmpBJ, XMP-xmpMM, XMP-xmpPLUS, XMP-xmpRights,
XMP-xmpTPg
|
| 2 (Category) |
Audio, Author, Camera, ExifTool, Image, Location, Other, Printing, Time,
Unknown, Video
|
Example:
@groupList = Image::ExifTool::GetAllGroups($family);
|
Get type of file given file name.
| Prototype | GetFileType(;$) |
| Inputs |
0) [optional] File name (or just an extension)
|
| Returns | A string, based on the file extension, which
represents the type of file, or undefined if the file type isn't supported by
ExifTool. In array context, may return more than one file type if the file
may be different formats. Returns a list of extensions for all recognized
file types if no input extension is specified.
|
Example:
my $type = Image::ExifTool::GetFileType($filename);
|
Can the specified file or file type be written?
| Prototype | CanWrite($) |
| Inputs |
0) File name, file extension, or file type |
| Returns | True if the file type can be
written (edited). |
Example:
my $writable = Image::ExifTool::CanWrite($filename);
|
Can the specified file or file type be created?
| Prototype | CanCreate($) |
| Inputs |
0) File name, file extension, or file type |
| Returns | True if the file type can be created
from scratch. Currently, this can only be done with XMP files. |
Example:
my $creatable = Image::ExifTool::CanCreate($filename);
|
<-- Back to ExifTool home page