Class: Lizard::Image

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

Constant Summary collapse

TYPES = 
['jpeg', 'png', 'gif']

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(data) ⇒ Image

Returns a new instance of Image.



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# File 'lib/lizard/image.rb', line 18

def initialize(data)
  @data = data
  @properties = identify
end

Class Method Details

.is_image?(data) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/lizard/image.rb', line 11

def self.is_image?(data)
  image = Image.new(data)
  true
rescue NotAnImage
  false
end

Instance Method Details

#color_model ⇒ Object 



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# File 'lib/lizard/image.rb', line 51

def color_model
  case color_space
  when/CMYK/i then "CMYK"
  when /RGB/i then "RBG"
  else nil
  end
end

#color_space ⇒ Object 



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# File 'lib/lizard/image.rb', line 47

def color_space
  @properties[:color_space].strip
end

#crop(width, height, type = "jpeg") ⇒ Object 



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# File 'lib/lizard/image.rb', line 95

def crop(width, height, type = "jpeg")
  unless TYPES.include?(type)
    raise InvalidFileType, "#{type} is not valid. Choose from #{TYPES.join(', ')}"
  end

  command = ['convert', '-', '-gravity', 'center', '-extent', "#{width.to_i}x#{height.to_i}", "#{type}:-"]
  stdout, stderr, exit_code = Lizard.run_command(command, @data)
  if exit_code == 0
    Image.new(stdout)
  else
    raise CropFailed, "Image could not be cropped (#{stderr})"
  end
end

#data ⇒ Object 



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# File 'lib/lizard/image.rb', line 27

def data
  @data
end

#height ⇒ Object 



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# File 'lib/lizard/image.rb', line 43

def height
  @properties[:height].to_i
end

#histogram ⇒ Object 



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# File 'lib/lizard/image.rb', line 109

def histogram
  @histogram ||= Histogram.new(@data)
end

#inspect ⇒ Object 



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# File 'lib/lizard/image.rb', line 23

def inspect
  "#<Lizard::Image type=#{type}, size=#{width}x#{height}, bytes=#{@data.bytesize}>"
end

#resize(width, height, mode = :resize_down_only, type = "jpeg") ⇒ Object 



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# File 'lib/lizard/image.rb', line 59

def resize(width, height, mode = :resize_down_only, type = "jpeg")
  case mode
  when :default
    operator = ""
  when :resize_down_only
    operator = ">"
  when :fill
    operator = "^"
  when :ignore_aspect
    operator = "!"
  else
    raise InvalidResizeMode, "#{mode} is not a valid"
  end

  unless TYPES.include?(type)
    raise InvalidFileType, "#{type} is not valid. Choose from #{TYPES.join(', ')}"
  end

  command = [
    'convert', '-', '-profile', Lizard::COLOR_PROFILES["RGB"], '-flatten',
    '-resize', "#{width.to_i}x#{height.to_i}#{operator}",
    "#{type}:-"
  ]
  if self.color_model == "CMYK"
    command.insert(4, '-profile')
    command.insert(5, COLOR_PROFILES[self.color_model].to_s)
  end

  stdout, stderr, exit_code = Lizard.run_command(command, @data)
  if exit_code == 0
    Image.new(stdout)
  else
    raise ResizeFailed, "Image could not be resized (#{stderr})"
  end
end

#resolution ⇒ Object 



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# File 'lib/lizard/image.rb', line 35

def resolution
  @properties[:resolution]
end

#type ⇒ Object 



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# File 'lib/lizard/image.rb', line 31

def type
  @properties[:type]
end

#width ⇒ Object 



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# File 'lib/lizard/image.rb', line 39

def width
  @properties[:width].to_i
end