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