xmp

xmp - Extensible Metadata Platform (XMP) parser

XMP provides an object oriented interface to XMP data. XMP data can be found in PDF, JPEG, GIF, PNG, and many other formats.

Supported Formats

Format	File extension	Additional dependency
JPEG	.jpeg, .jpg	exifr/jpeg
TIFF	.tiff, .tif	exifr/tiff
XMP Files	.xmp, .xml	none

Usage

require 'xmp'
xmp = XMP.new('example.jpg')
xmp.dc.subject # => ["something interesting"]

xmp.namespaces.each do |namespace|
  xmp[namespace].attributes.each do |attribute|
    puts "#{namespace}.#{attribute}: #{xmp[namespace][attribute].inspect}"
  end
end

XMP.new accepts:

• Paths to files (it will choose based on file extension)
• File objects (it will choose based on file extension)
• Nokogiri documents or XML strings

Attributes can be accessed in the following ways:

# assuming an XMP entry AttributeName within the NamespaceName namespace, these are all equivalent
xmp['NamespaceName']['AttributeName']
xmp.namespace_name.attribute_name
xmp.NamespaceName.AttributeName

# you can also mix them
xmp.namespace_name['AttributeName']

# or convert the data to an actual hash
xmp.to_h # => { 'NamespaceName' => { … }, … }

Installation

$ gem install xmp
$ gem install exifr # optional, for jpeg/tiff support

Or you can add it to your Gemfile:

gem 'xmp',   '~> 1.0'
gem 'exifr', '~> 1.3'

Requirements

• Ruby 2 (supported on >= 2.6, though xmp may work on earlier versions) or Ruby 3
• nokogiri (>= 1.10). The xmp gem depends on this gem. It will be installed automatically.
  • On Ruby 2.6, nokogiri 1.13.10 will be installed; nokogiri >= 1.14 require Ruby 2.7.
  • On Ruby 2.7, nokogiri 1.15.5 will be installed; nokogiri >= 1.16 require Ruby 3.
  • See https://nokogiri.org/CHANGELOG.html for nokogiri support for older or newer Ruby versions.
• exifr (>= 1.3). This gem is optional. If you need it, add it to your Gemfile.

Development

Fork it at https://github.com/amberbit/xmp

$ bundle install # install development dependencies
$ rake spec      # run specs

License

Ruby's license.

Copyright (c) 2011 Wojciech Piekutowski, AmberBit (http://amberbit.com) and contributors.