XMP provides object oriented interface to XMP data (en.wikipedia.org/wiki/Extensible_Metadata_Platform). XMP data can be found in PDF, JPEG, GIF, PNG, and many other formats.

Currently only JPEG is supported through exifr gem.

# gem install xmp exifr
require 'xmp'
require 'exifr'
require 'open-uri'

img = EXIFR::JPEG.new('spec/fixtures/multiple-app1.jpg')
xmp = XMP.parse(img)
xmp.dc.subject #=> ["something interesting"]

# explore XMP data
xmp.namespaces.each do |namespace_name|
  namespace = xmp.send(namespace_name)
  namespace.attributes.each do |attr|
    puts "#{namespace_name}.#{attr}: " + namespace.send(attr).inspect
  end
end

gem install xmp
# for JPEG support
gem install exifr -v ">=1.0.4"

• Ruby 1.8.7, 1.9.2

• Nokogiri 1.4

• EXIFR >= 1.0.4

Fork it at github.com/amberbit/xmp

# install development dependencies
bundle install
# run specs
rake spec

Ruby’s license.

Copyright © 2011 Wojciech Piekutowski, AmberBit (amberbit.com)