Class: ImageVoodoo::Metadata

Inherits:
Object
  • Object
show all
Defined in:
lib/image_voodoo/metadata.rb

Overview

Metadata contained within the image.

Instance Method Summary collapse

Constructor Details

#initialize(io) ⇒ Metadata

Returns a new instance of Metadata.



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# File 'lib/image_voodoo/metadata.rb', line 9

def initialize(io)
  @metadata = com.drew.imaging.ImageMetadataReader.read_metadata io
end

Instance Method Details

#[](dirname) ⇒ Object

This will return a fairly useless Directory if you ask for one and there is no data in the image you are requesting. The reason for doing this is so queries like ‘md[:Orientation]’ can run and just return nil since I think this is the common case.

See Directory#exists? if you want to make sure the group you are requesting actually exists or not.

Raises:

  • (ArgumentError) 


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# File 'lib/image_voodoo/metadata.rb', line 22

def [](dirname)
  dirclass = DIRECTORY_MAP[dirname.to_s]

  raise ArgumentError, "Uknown metadata group: #{dirname}" unless dirclass

  dirclass.new @metadata
end

#height ⇒ Object

FIXME: I wonder if this needs to fall back to try all other directories for Image Height



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# File 'lib/image_voodoo/metadata.rb', line 46

def height
  self['Exif Sub IFD']['Exif Image Height']
end

#make ⇒ Object

Common metadata methods exposed as convenience functions so users do not need to dig around in the various directories



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# File 'lib/image_voodoo/metadata.rb', line 32

def make
  self[:IFD0][:Make]
end

#model ⇒ Object 



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# File 'lib/image_voodoo/metadata.rb', line 36

def model
  self[:IFD0][:Model]
end

#orientation ⇒ Object 



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# File 'lib/image_voodoo/metadata.rb', line 40

def orientation
  self[:IFD0][:Orientation]
end

#to_s ⇒ Object 



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# File 'lib/image_voodoo/metadata.rb', line 54

def to_s
  out = StringIO.new
  out.puts "[{dir name}] - {tag name} = {tag descr}"
  out.puts "---------------------------------------"
  @metadata.directories.each do |directory|
    directory.tags.each do |tag|
      out.puts "[#{directory.name}] - #{tag.tag_name} = #{tag.description}"
    end
  end
  out.string
end

#width ⇒ Object 



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# File 'lib/image_voodoo/metadata.rb', line 50

def width
  self['Exif Sub IFD']['Exif Image Width']
end