Class: MiniMagick::Image::Info

Inherits:
Object
  • Object
show all
Defined in:
lib/mini_magick/image/info.rb

Constant Summary collapse

ASCII_ENCODED_EXIF_KEYS = 
%w[ExifVersion FlashPixVersion]

Instance Method Summary collapse

Constructor Details

#initialize(path) ⇒ Info

Returns a new instance of Info.



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# File 'lib/mini_magick/image/info.rb', line 7

def initialize(path)
  @path = path
  @info = {}
end

Instance Method Details

#[](value, *args) ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 12

def [](value, *args)
  case value
  when "format", "width", "height", "dimensions", "size"
    cheap_info(value)
  when "colorspace"
    colorspace
  when "mime_type"
    mime_type
  when "resolution"
    resolution(*args)
  when "signature"
    signature
  when /^EXIF\:/i
    raw_exif(value)
  when "exif"
    exif
  when "details"
    details
  else
    raw(value)
  end
end

#cheap_info(value) ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 39

def cheap_info(value)
  @info.fetch(value) do
    format, width, height, size = self["%m %w %h %b"].split(" ")

    @info.update(
      "format"     => format,
      "width"      => Integer(width),
      "height"     => Integer(height),
      "dimensions" => [Integer(width), Integer(height)],
      "size"       => size.to_i,
    )

    @info.fetch(value)
  end
rescue ArgumentError, TypeError
  raise MiniMagick::Invalid, "image data can't be read"
end

#clear ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 35

def clear
  @info.clear
end

#colorspace ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 57

def colorspace
  @info["colorspace"] ||= self["%r"]
end

#decode_comma_separated_ascii_characters(encoded_value) ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 129

def decode_comma_separated_ascii_characters(encoded_value)
  return encoded_value unless encoded_value.include?(',')
  encoded_value.scan(/\d+/).map(&:to_i).map(&:chr).join
end

#details ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 100

def details
  @info["details"] ||= (
    details_string = identify(&:verbose)
    details_string.each_line.with_object([]).inject({}) do |details_hash, (line, key_stack)|
      level = line[/^\s*/].length / 2 - 1
      next details_hash if level == -1 # we ignore the root level
      key_stack.pop if level < key_stack.size

      key, _, value = line.partition(/:[\s\n]/).map(&:strip)
      hash = key_stack.inject(details_hash) { |hash, key| hash.fetch(key) }
      if value.empty?
        hash[key] = {}
        key_stack.push key
      else
        hash[key] = value
      end

      details_hash
    end
  )
end

#exif ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 77

def exif
  @info["exif"] ||= (
    output = self["%[EXIF:*]"]
    pairs = output.gsub(/^exif:/, "").split("\n").map { |line| line.split("=") }
    Hash[pairs].tap do |hash|
      ASCII_ENCODED_EXIF_KEYS.each do |key|
        next unless hash.has_key?(key)

        value = hash[key]
        hash[key] = decode_comma_separated_ascii_characters(value)
      end
    end
  )
end

#identify ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 122

def identify
  MiniMagick::Tool::Identify.new do |builder|
    yield builder if block_given?
    builder << "#{@path}[0]"
  end
end

#mime_type ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 61

def mime_type
  "image/#{self["format"].downcase}"
end

#raw(value) ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 92

def raw(value)
  @info["raw:#{value}"] ||= identify { |b| b.format(value) }
end

#raw_exif(value) ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 73

def raw_exif(value)
  self["%[#{value}]"]
end

#resolution(unit = nil) ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 65

def resolution(unit = nil)
  output = identify do |b|
    b.units unit if unit
    b.format "%x %y"
  end
  output.split(" ").map(&:to_i)
end

#signature ⇒ Object 



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# File 'lib/mini_magick/image/info.rb', line 96

def signature
  @info["signature"] ||= self["%#"]
end