PDF Tags
The tags listed in the PDF tables below are those which are used by ExifTool
to extract meta information, but they are only a small fraction of the total
number of available PDF tags.
When writing PDF files, ExifTool uses an increment update. This has the
advantages of being fast and reversible. The original PDF can be easily
recovered by deleting the PDF-update
pseudo-group (with
-PDF-update:all=
on the command line). But there are two main
disadvantages to this technique:
1) A linearized PDF file is no longer linearized after the update, so it
must be subsequently re-linearized if this is required.
2) All metadata edits are reversible. While this would normally be
considered an advantage, it is a potential security problem because old
information is never actually deleted from the file.
As well as the tags listed below, the PDF specification allows for
user-defined tags to exist in the Info dictionary. These tags, which should
have corresponding XMP-pdfx entries in the XMP of the PDF XML Metadata
object, are also extracted by ExifTool.
Writable specifies the value format, and may be string
, date
,
integer
, real
, boolean
or name
for PDF tags.
Tag ID | Tag Name |
Writable | Values / Notes |
'AAPL:Keywords' |
AppleKeywords |
string+ |
(keywords written by Apple utilities, although they seem to use PDF:Keywords
when reading) |
'Author' |
Author |
string |
|
'CreationDate' |
CreateDate |
date |
|
'Creator' |
Creator |
string |
|
'Keywords' |
Keywords |
string+ |
|
'ModDate' |
ModifyDate |
date |
|
'Producer' |
Producer |
string |
|
'Subject' |
Subject |
string |
|
'Title' |
Title |
string |
|
'Trapped' |
Trapped |
string! |
|
|
This is the PDF document catalog.
Tag ID | Tag Name |
Writable | Values / Notes |
'XML_stream' |
XMP |
- |
--> XMP Tags |
|
Tag ID | Tag Name |
Writable | Values / Notes |
'Count' |
PageCount |
N |
|
'Kids' |
Kids |
- |
--> PDF Kids Tags |
|
Tag ID | Tag Name |
Writable | Values / Notes |
'_stream' |
_stream |
- |
--> Photoshop Tags |
|
Tag ID | Tag Name |
Writable | Values / Notes |
'AIMetaData' |
AIMetaData |
- |
--> PDF AIMetaData Tags |
'AIPrivateData' |
AIPrivateData |
- |
--> PostScript Tags
(the ExtractEmbedded option enables information to be extracted from embedded
PostScript documents in the AIPrivateData stream) |
'ContainerVersion' |
ContainerVersion |
N |
|
'CreatorVersion' |
CreatorVersion |
N |
|
'RoundTripVersion' |
RoundTripVersion |
N |
|
|
Tag ID | Tag Name |
Writable | Values / Notes |
'_stream' |
_stream |
- |
--> PostScript Tags |
|
(This document generated automatically by Image::ExifTool::BuildTagLookup)
Last revised Oct 27, 2009
<-- ExifTool Tag Names