Class: EXIFR::TIFF

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/tiff.rb

Overview

TIFF decoder

Date properties

The properties :date_time, :date_time_original, :date_time_digitized coerced into Time objects.

Orientation

The property :orientation describes the subject rotated and/or mirrored in relation to the camera. It is translated to one of the following instances:

  • TopLeftOrientation

  • TopRightOrientation

  • BottomRightOrientation

  • BottomLeftOrientation

  • LeftTopOrientation

  • RightTopOrientation

  • RightBottomOrientation

  • LeftBottomOrientation

These instances of Orientation have two methods:

  • to_i; return the original integer

  • transform_rmagick(image); transforms the given RMagick::Image to a viewable version

Examples

EXIFR::TIFF.new('DSC_0218.TIF').width           # => 3008
EXIFR::TIFF.new('DSC_0218.TIF')[1].width        # => 160
EXIFR::TIFF.new('DSC_0218.TIF').model           # => "NIKON D1X"
EXIFR::TIFF.new('DSC_0218.TIF').date_time       # => Tue May 23 19:15:32 +0200 2006
EXIFR::TIFF.new('DSC_0218.TIF').exposure_time   # => Rational(1, 100)
EXIFR::TIFF.new('DSC_0218.TIF').orientation     # => EXIFR::TIFF::Orientation

Defined Under Namespace

Classes: Data, Field, IFD, Orientation

Constant Summary collapse

TAG_MAPPING =

:nodoc:

{}
IFD_TAGS =

:nodoc:

[:image, :exif, :gps]
ORIENTATIONS =

:nodoc:

[]
ADAPTERS =

:nodoc:

Hash.new { proc { |v| v } }
TAGS =

Names for all recognized TIFF fields.

([TAG_MAPPING.keys, TAG_MAPPING.values.map{|v|v.values}].flatten.uniq - IFD_TAGS).map{|v|v.to_s}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(file) ⇒ TIFF

file is a filename or an IO object.



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# File 'lib/tiff.rb', line 306

def initialize(file)
  data = Data.new(file)

  case data[0..1]
  when 'II'; data.endianess = 'v'
  when 'MM'; data.endianess = 'n'
  else; raise 'no II or MM marker found'
  end

  @ifds = [IFD.new(data)]
  while ifd = @ifds.last.next
    break if @ifds.find{|i| i.offset == ifd.offset}
    @ifds << ifd
  end

  @jpeg_thumbnails = @ifds.map do |ifd|
    if ifd.jpeg_interchange_format && ifd.jpeg_interchange_format_length
      start, length = ifd.jpeg_interchange_format, ifd.jpeg_interchange_format_length
      data[start..(start + length)]
    end
  end.compact
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args) ⇒ Object

Dispatch to first image.



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# File 'lib/tiff.rb', line 345

def method_missing(method, *args)
  super unless args.empty?

  if @ifds.first.respond_to?(method)
    @ifds.first.send(method)
  elsif TAGS.include?(method.to_s)
    @ifds.first.to_hash[method]
  else
    super
  end
end

Instance Attribute Details

#jpeg_thumbnails ⇒ Object (readonly)

JPEG thumbnails



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# File 'lib/tiff.rb', line 41

def jpeg_thumbnails
  @jpeg_thumbnails
end

Class Method Details

.instance_methods(include_super = true) ⇒ Object

:nodoc:



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# File 'lib/tiff.rb', line 369

def instance_methods(include_super = true) # :nodoc:
  (instance_methods_without_tiff_extras(include_super) + TAGS + IFD.instance_methods(false)).uniq
end

.instance_methods_without_tiff_extras ⇒ Object 



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# File 'lib/tiff.rb', line 368

alias instance_methods_without_tiff_extras instance_methods

Instance Method Details

#[](index) ⇒ Object

Get index image.



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# File 'lib/tiff.rb', line 340

def [](index)
  index.is_a?(Symbol) ? to_hash[index] : @ifds[index]
end

#each ⇒ Object

Yield for each image.



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# File 'lib/tiff.rb', line 335

def each
  @ifds.each { |ifd| yield ifd }
end

#height ⇒ Object

Convenience method to access image height.



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# File 'lib/tiff.rb', line 378

def height; @ifds.first.height; end

#inspect ⇒ Object

:nodoc:



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# File 'lib/tiff.rb', line 383

def inspect # :nodoc:
  @ifds.inspect
end

#methods ⇒ Object

:nodoc:



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# File 'lib/tiff.rb', line 363

def methods # :nodoc:
  (super + TAGS + IFD.instance_methods(false)).uniq
end

#respond_to?(method) ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/tiff.rb', line 357

def respond_to?(method) # :nodoc:
  super ||
    (@ifds && @ifds.first && @ifds.first.respond_to?(method)) ||
    TAGS.include?(method.to_s)
end

#size ⇒ Object

Number of images.



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# File 'lib/tiff.rb', line 330

def size
  @ifds.size
end

#to_hash ⇒ Object

Get a hash presentation of the (first) image.



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# File 'lib/tiff.rb', line 381

def to_hash; @ifds.first.to_hash; end

#width ⇒ Object

Convenience method to access image width.



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# File 'lib/tiff.rb', line 375

def width; @ifds.first.width; end