NAME¶
Image::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 2003-2014, 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)
