Image::ExifTool::AFCP(User Contributed Perl DocumentatImage::ExifTool::AFCP(3)NAMEImage::ExifTool::AFCP - Read/write AFCP trailer
SYNOPSIS
This module is used by Image::ExifTool
DESCRIPTION
This module contains definitions required by Image::ExifTool to extract
information from the AFCP trailer. Although the AFCP specification is
compatible with various file formats, ExifTool currently only processes
AFCP in JPEG images.
NOTES
AFCP is a specification which allows meta information (including IPTC)
to be appended to the end of a file.
It is a poorly designed protocol because (like TIFF) it uses absolute
offsets to specify data locations. This is a huge blunder because it
makes the AFCP information dependent on the file length, so it is
easily invalidated by image editing software which doesn't recognize
the AFCP trailer to fix up these offsets when the file length changes.
ExifTool will attempt to fix these invalid offsets if possible.
Scanning for AFCP information may be time consuming, especially when
reading from a sequential device, since the information is at the end
of the file. In these instances, the ExifTool FastScan option may be
used to disable scanning for AFCP information.
AUTHOR
Copyright 2003-2010, Phil Harvey (phil at owl.phy.queensu.ca)
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
REFERENCES
<http://www.tocarte.com/media/axs_afcp_spec.pdf>
SEE ALSO
"AFCP Tags" in Image::ExifTool::TagNames, Image::ExifTool(3pm)perl v5.10.1 2010-01-04 Image::ExifTool::AFCP(3)