# phpman > perldoc > Image::ExifTool::PDF

## NAME
    [Image::ExifTool::PDF](https://www.chedong.com/phpMan.php/perldoc/Image%3A%3AExifTool%3A%3APDF/markdown) - Read PDF meta information

## SYNOPSIS
    This module is loaded automatically by [Image::ExifTool](https://www.chedong.com/phpMan.php/perldoc/Image%3A%3AExifTool/markdown) when required.

## DESCRIPTION
    This code reads meta information from PDF (Adobe Portable Document Format) files. It supports
    object streams introduced in PDF-1.5 but only with a limited set of Filter and Predictor
    algorithms, however all standard encryption methods through PDF-1.7 extension level 3 are
    supported, including AESV2 (AES-128) and AESV3 (AES-256).

## AUTHOR
    Copyright 2003-2022, Phil Harvey (philharvey66 at gmail.com)

    This library is free software; you can redistribute it and/or modify it under the same terms as
    Perl itself.

## REFERENCES
    <<http://partners.adobe.com/public/developer/pdf/index_reference.html>>
    [Crypt::RC4](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3ARC4/markdown)
    <<http://www.adobe.com/devnet/acrobat/pdfs/PDF32000_2008.pdf>>
    <<http://www.adobe.com/content/dam/Adobe/en/devnet/pdf/pdfs/adobe_supplement_iso32000.pdf>>
    <<http://tools.ietf.org/search/rfc3454>>
    <<http://www.armware.dk/RFC/rfc/rfc4013.html>>

## SEE ALSO
    "PDF Tags" in [Image::ExifTool::TagNames](https://www.chedong.com/phpMan.php/perldoc/Image%3A%3AExifTool%3A%3ATagNames/markdown), Image::[ExifTool(3pm)](https://www.chedong.com/phpMan.php/man/ExifTool/3pm/markdown)