class Magick::OptionalMethodArguments

Collects non-specific optional method arguments

def define(key, val = nil)

set(key, val) corresponds to -set option:key val 
def define(key, val = nil)
  @img.define(key, val)
end

def highlight_color=(color)

accepts Pixel object or color name 
def highlight_color=(color)
  color = @img.to_color(color) if color.respond_to?(:to_color)
  @img.define('highlight-color', color)
end

def initialize(img) 

def initialize(img)
  @img = img
end

def lowlight_color=(color)

accepts Pixel object or color name 
def lowlight_color=(color)
  color = @img.to_color(color) if color.respond_to?(:to_color)
  @img.define('lowlight-color', color)
end

def method_missing(mth, val)

miscellaneous options like -verbose 
def method_missing(mth, val)
  @img.define(mth.to_s.tr('_', '-'), val)
end