diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 97bcc23..5f68262 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -43,6 +43,10 @@ Metrics/LineLength:
 Metrics/MethodLength:
   Max: 18
 
+Metrics/ParameterLists:
+  Exclude:
+    - 'app/services/riiif/imagemagick_command_factory.rb'
+
 # Offense count: 1
 # Configuration parameters: EnforcedStyle, SupportedStyles.
 # SupportedStyles: nested, compact
diff --git a/Gemfile b/Gemfile
index 0c4cc1f..3d18d76 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,5 @@
 source 'https://rubygems.org'
 
+gem 'byebug'
 # Specify your gem's dependencies in riiif.gemspec
 gemspec
diff --git a/app/models/riiif/file.rb b/app/models/riiif/file.rb
index 2fa1699..3c9879f 100644
--- a/app/models/riiif/file.rb
+++ b/app/models/riiif/file.rb
@@ -3,6 +3,7 @@ class File
     attr_reader :path
 
     class_attribute :info_extractor_class
+    # TODO: add alternative that uses kdu_jp2info
     self.info_extractor_class = ImageMagickInfoExtractor
 
     # @param input_path [String] The location of an image file
@@ -20,6 +21,8 @@ def self.read(stream, ext)
     end
     deprecation_deprecate read: 'Riiif::File.read is deprecated and will be removed in version 2.0'
 
+    # Yields a tempfile to the provided block
+    # @return [Riiif::File] a file backed by the Tempfile
     def self.create(ext = nil, _validate = true, &block)
       tempfile = Tempfile.new(['mini_magick', ext.to_s.downcase])
       tempfile.binmode
@@ -32,22 +35,26 @@ def self.create(ext = nil, _validate = true, &block)
     deprecation_deprecate create: 'Riiif::File.create is deprecated and will be removed in version 2.0'
 
     # @param [Transformation] transformation
-    def extract(transformation)
-      command = command_factory.build(path, transformation)
-      execute(command)
+    # @param [ImageInformation] image_info
+    # @return [String] the processed image data
+    def extract(transformation, image_info = info)
+      transformer.transform(path, image_info, transformation)
     end
 
-    def info
-      @info ||= info_extractor_class.new(path).extract
+    def transformer
+      if Riiif.kakadu_enabled? && path.ends_with?('.jp2')
+        KakaduTransformer
+      else
+        ImagemagickTransformer
+      end
     end
 
-    delegate :execute, to: Riiif::CommandRunner
-    private :execute
-
-    private
+    def info
+      @info ||= info_extractor.extract
+    end
 
-      def command_factory
-        ImagemagickCommandFactory
-      end
+    def info_extractor
+      @info_extractor ||= info_extractor_class.new(path)
+    end
   end
 end
diff --git a/app/models/riiif/image.rb b/app/models/riiif/image.rb
index 52107fe..3216327 100644
--- a/app/models/riiif/image.rb
+++ b/app/models/riiif/image.rb
@@ -4,17 +4,17 @@
 # These explict requires are needed because in some contexts the Rails
 # autoloader can either: unload already loaded classes, or cause a lock while
 # trying to load a needed class.
-require_dependency 'riiif/region/imagemagick/absolute_decoder'
-require_dependency 'riiif/region/imagemagick/full_decoder'
-require_dependency 'riiif/region/imagemagick/percentage_decoder'
-require_dependency 'riiif/region/imagemagick/square_decoder'
+require_dependency 'riiif/region/absolute'
+require_dependency 'riiif/region/full'
+require_dependency 'riiif/region/percentage'
+require_dependency 'riiif/region/square'
 
-require_dependency 'riiif/size/imagemagick/absolute_decoder'
-require_dependency 'riiif/size/imagemagick/best_fit_decoder'
-require_dependency 'riiif/size/imagemagick/full_decoder'
-require_dependency 'riiif/size/imagemagick/height_decoder'
-require_dependency 'riiif/size/imagemagick/percent_decoder'
-require_dependency 'riiif/size/imagemagick/width_decoder'
+require_dependency 'riiif/size/absolute'
+require_dependency 'riiif/size/best_fit'
+require_dependency 'riiif/size/full'
+require_dependency 'riiif/size/height'
+require_dependency 'riiif/size/percent'
+require_dependency 'riiif/size/width'
 
 module Riiif
   class Image
@@ -54,12 +54,13 @@ def file
 
     ##
     # @param [ActiveSupport::HashWithIndifferentAccess] args
+    # @return [String] the image data
     def render(args)
       cache_opts = args.select { |a| %w(region size quality rotation format).include? a.to_s }
       key = Image.cache_key(id, cache_opts)
 
       cache.fetch(key, compress: true, expires_in: Image.expires_in) do
-        file.extract(OptionDecoder.decode(args, info))
+        file.extract(OptionDecoder.decode(args, info), info)
       end
     end
 
diff --git a/app/models/riiif/image_information.rb b/app/models/riiif/image_information.rb
index 1a948cc..2d38e08 100644
--- a/app/models/riiif/image_information.rb
+++ b/app/models/riiif/image_information.rb
@@ -14,6 +14,10 @@ def to_h
       { width: width, height: height }
     end
 
+    def aspect_ratio
+      width.to_f / height
+    end
+
     def [](key)
       to_h[key]
     end
diff --git a/app/models/riiif/transformation.rb b/app/models/riiif/transformation.rb
new file mode 100644
index 0000000..a516378
--- /dev/null
+++ b/app/models/riiif/transformation.rb
@@ -0,0 +1,35 @@
+module Riiif
+  # Represents a IIIF request
+  class Transformation
+    attr_reader :crop, :size, :quality, :rotation, :format
+    def initialize(crop, size, quality, rotation, format)
+      @crop = crop
+      @size = size
+      @quality = quality
+      @rotation = rotation
+      @format = format
+    end
+
+    # Create a clone of this Transformation, scaled by the factor
+    # @param [Integer] factor the scale for the new transformation
+    # @return [Transformation] a new transformation, scaled by factor
+    def reduce(factor)
+      Transformation.new(crop.dup,
+                         size.reduce(factor),
+                         quality,
+                         rotation,
+                         format)
+    end
+
+    # Create a clone of this Transformation, without the crop
+    # @return [Transformation] a new transformation
+    # TODO: it would be nice if we didn't need image_info
+    def without_crop(image_info)
+      Transformation.new(Region::Full.new(image_info),
+                         size.dup,
+                         quality,
+                         rotation,
+                         format)
+    end
+  end
+end
diff --git a/app/services/riiif/command_runner.rb b/app/services/riiif/command_runner.rb
index ea89f14..37e895f 100644
--- a/app/services/riiif/command_runner.rb
+++ b/app/services/riiif/command_runner.rb
@@ -6,6 +6,8 @@ class CommandRunner
     include ActiveSupport::Benchmarkable
     delegate :logger, to: :Rails
 
+    # TODO: this is being loaded into memory.  We could make this a stream.
+    # @return [String] all the image data
     def execute(command)
       out = nil
       benchmark("Riiif executed #{command}") do
diff --git a/app/services/riiif/crop.rb b/app/services/riiif/crop.rb
new file mode 100644
index 0000000..214b543
--- /dev/null
+++ b/app/services/riiif/crop.rb
@@ -0,0 +1,54 @@
+module Riiif
+  # Represents a cropping operation
+  class Crop
+    attr_reader :image_info
+
+    # @return [String] a region for imagemagick to decode
+    #                  (appropriate for passing to the -crop parameter)
+    def to_imagemagick
+      "#{width}x#{height}+#{offset_x}+#{offset_y}"
+    end
+
+    # @return [String] a region for kakadu to decode
+    #                  (appropriate for passing to the -region parameter)
+    def to_kakadu
+      "\{#{decimal_offset_y},#{decimal_offset_x}\},\{#{decimal_height},#{decimal_width}\}"
+    end
+
+    attr_reader :offset_x
+
+    attr_reader :offset_y
+
+    # @return [Integer] the height in pixels
+    def height
+      image_info.height
+    end
+
+    # @return [Integer] the width in pixels
+    def width
+      image_info.width
+    end
+
+    # @return [Float] the fractional height with respect to the original size
+    def decimal_height(n = height)
+      n.to_f / image_info.height
+    end
+
+    # @return [Float] the fractional width with respect to the original size
+    def decimal_width(n = width)
+      n.to_f / image_info.width
+    end
+
+    def decimal_offset_x
+      offset_x.to_f / image_info.width
+    end
+
+    def decimal_offset_y
+      offset_y.to_f / image_info.height
+    end
+
+    def maintain_aspect_ratio?
+      (height / width) == (image_info.height / image_info.width)
+    end
+  end
+end
diff --git a/app/services/riiif/imagemagick_command_factory.rb b/app/services/riiif/imagemagick_command_factory.rb
index 722cbe1..8a98ba9 100644
--- a/app/services/riiif/imagemagick_command_factory.rb
+++ b/app/services/riiif/imagemagick_command_factory.rb
@@ -9,35 +9,29 @@ class ImagemagickCommandFactory
 
     # A helper method to instantiate and invoke build
     # @param [String] path the location of the file
+    # @param info [ImageInformation] information about the source
     # @param [Transformation] transformation
     # @param [Integer] compression (85) the compression level to use (set 0 for no compression)
     # @param [String] sampling_factor ("4:2:0") the chroma sample factor (set 0 for no compression)
     # @param [Boolean] strip_metadata (true) do we want to strip EXIF tags?
-    # @return [String] a command for running imagemagick to produce the requested output
-    def self.build(path, transformation, compression: 85, sampling_factor: '4:2:0', strip_metadata: true)
-      new(path, transformation,
-          compression: compression,
-          sampling_factor: sampling_factor,
-          strip_metadata: strip_metadata).build
-    end
-
-    # A helper method to instantiate and invoke build
-    # @param [String] path the location of the file
-    # @param [Transformation] transformation
-    # @param [Integer] compression the compression level to use (set 0 for no compression)
-    def initialize(path, transformation, compression:, sampling_factor:, strip_metadata:)
+    def initialize(path, info, transformation, compression: 85, sampling_factor: '4:2:0', strip_metadata: true)
       @path = path
+      @info = info
       @transformation = transformation
       @compression = compression
       @sampling_factor = sampling_factor
       @strip_metadata = strip_metadata
     end
 
-    attr_reader :path, :transformation, :compression, :sampling_factor, :strip_metadata
+    attr_reader :path, :info, :transformation, :compression, :sampling_factor, :strip_metadata
 
     # @return [String] a command for running imagemagick to produce the requested output
-    def build
-      [external_command, crop, size, rotation, colorspace, quality, sampling, metadata, output].join
+    def command
+      [external_command, crop, size, rotation, colorspace, quality, sampling, metadata, input, output].join
+    end
+
+    def reduction_factor
+      nil
     end
 
     private
@@ -50,16 +44,23 @@ def jpeg?
         transformation.format == 'jpg'.freeze
       end
 
+      def input
+        " #{path}"
+      end
+
+      # pipe the output to STDOUT
       def output
-        " #{path} #{transformation.format}:-"
+        " #{transformation.format}:-"
       end
 
       def crop
-        " -crop #{transformation.crop}" if transformation.crop
+        directive = transformation.crop.to_imagemagick
+        " -crop #{directive}" if directive
       end
 
       def size
-        " -resize #{transformation.size}" if transformation.size
+        directive = transformation.size.to_imagemagick
+        " -resize #{directive}" if directive
       end
 
       def rotation
diff --git a/app/services/riiif/imagemagick_transformer.rb b/app/services/riiif/imagemagick_transformer.rb
new file mode 100644
index 0000000..5bebe8c
--- /dev/null
+++ b/app/services/riiif/imagemagick_transformer.rb
@@ -0,0 +1,8 @@
+module Riiif
+  # Transforms an image using Imagemagick
+  class ImagemagickTransformer < AbstractTransformer
+    def command_factory
+      ImagemagickCommandFactory
+    end
+  end
+end
diff --git a/app/services/riiif/kakadu_command_factory.rb b/app/services/riiif/kakadu_command_factory.rb
new file mode 100644
index 0000000..55cdee9
--- /dev/null
+++ b/app/services/riiif/kakadu_command_factory.rb
@@ -0,0 +1,63 @@
+# frozen_string_literal: true
+
+module Riiif
+  # Builds a command to run a transformation using Kakadu
+  class KakaduCommandFactory
+    class_attribute :external_command
+    self.external_command = 'kdu_expand'
+
+    # A helper method to instantiate and invoke build
+    # @param [String] path the location of the file
+    # @param info [ImageInformation] information about the source
+    # @param [Transformation] transformation
+    def initialize(path, info, transformation)
+      @path = path
+      @info = info
+      @transformation = transformation
+    end
+
+    attr_reader :path, :info, :transformation
+
+    # @param tmp_file [String] the path to the temporary file
+    # @return [String] a command for running kdu_expand to produce the requested output
+    def command(tmp_file)
+      [external_command, quiet, input, threads, region, reduce, output(tmp_file)].join
+    end
+
+    def reduction_factor
+      @reduction_factor ||= transformation.size.reduction_factor
+    end
+
+    private
+
+      def input
+        " -i #{path}"
+      end
+
+      def output(output_filename)
+        " -o #{output_filename}"
+      end
+
+      def threads
+        ' -num_threads 4'
+      end
+
+      def quiet
+        ' -quiet'
+      end
+
+      def region
+        region_arg = transformation.crop.to_kakadu
+        " -region \"#{region_arg}\"" if region_arg
+      end
+
+      # kdu_expand is not capable of arbitrary scaling, but it does
+      # offer a -reduce argument which is capable of downscaling by
+      # factors of 2, significantly speeding decompression. We can
+      # use it if either the percent is <=50, or the height/width
+      # are <=50% of full size.
+      def reduce
+        " -reduce #{reduction_factor}" if reduction_factor && reduction_factor != 0
+      end
+  end
+end
diff --git a/app/services/riiif/link_name_service.rb b/app/services/riiif/link_name_service.rb
new file mode 100644
index 0000000..3787275
--- /dev/null
+++ b/app/services/riiif/link_name_service.rb
@@ -0,0 +1,8 @@
+module Riiif
+  # Creates names for a temporary file
+  class LinkNameService
+    def self.create
+      ::File.join(Dir.tmpdir, SecureRandom.uuid) + '.bmp'
+    end
+  end
+end
diff --git a/app/services/riiif/option_decoder.rb b/app/services/riiif/option_decoder.rb
index 63f475a..e6a92b5 100644
--- a/app/services/riiif/option_decoder.rb
+++ b/app/services/riiif/option_decoder.rb
@@ -52,14 +52,14 @@ def validate_format!(format)
 
     def decode_region(region)
       if region.nil? || region == 'full'
-        Riiif::Region::Imagemagick::FullDecoder.new.decode
+        Riiif::Region::Full.new(image_info)
       elsif md = /^pct:(\d+),(\d+),(\d+),(\d+)$/.match(region)
-        Riiif::Region::Imagemagick::PercentageDecoder
-          .new(image_info, md[1], md[2], md[3], md[4]).decode
+        Riiif::Region::Percentage
+          .new(image_info, md[1], md[2], md[3], md[4])
       elsif md = /^(\d+),(\d+),(\d+),(\d+)$/.match(region)
-        Riiif::Region::Imagemagick::AbsoluteDecoder.new(md[1], md[2], md[3], md[4]).decode
+        Riiif::Region::Absolute.new(image_info, md[1], md[2], md[3], md[4])
       elsif region == 'square'
-        Riiif::Region::Imagemagick::SquareDecoder.new(image_info).decode
+        Riiif::Region::Square.new(image_info)
       else
         raise InvalidAttributeError, "Invalid region: #{region}"
       end
@@ -68,17 +68,17 @@ def decode_region(region)
     # rubocop:disable Metrics/PerceivedComplexity
     def decode_size(size)
       if size.nil? || size == 'full'
-        Riiif::Size::Imagemagick::FullDecoder.new.decode
+        Riiif::Size::Full.new
       elsif md = /^,(\d+)$/.match(size)
-        Riiif::Size::Imagemagick::HeightDecoder.new(md[1]).decode
+        Riiif::Size::Height.new(image_info, md[1])
       elsif md = /^(\d+),$/.match(size)
-        Riiif::Size::Imagemagick::WidthDecoder.new(md[1]).decode
+        Riiif::Size::Width.new(image_info, md[1])
       elsif md = /^pct:(\d+(.\d+)?)$/.match(size)
-        Riiif::Size::Imagemagick::PercentDecoder.new(md[1]).decode
+        Riiif::Size::Percent.new(image_info, md[1])
       elsif md = /^(\d+),(\d+)$/.match(size)
-        Riiif::Size::Imagemagick::AbsoluteDecoder.new(md[1], md[2]).decode
+        Riiif::Size::Absolute.new(image_info, md[1], md[2])
       elsif md = /^!(\d+),(\d+)$/.match(size)
-        Riiif::Size::Imagemagick::BestFitDecoder.new(md[1], md[2]).decode
+        Riiif::Size::BestFit.new(image_info, md[1], md[2])
       else
         raise InvalidAttributeError, "Invalid size: #{size}"
       end
diff --git a/app/services/riiif/region/absolute.rb b/app/services/riiif/region/absolute.rb
new file mode 100644
index 0000000..dc49cc8
--- /dev/null
+++ b/app/services/riiif/region/absolute.rb
@@ -0,0 +1,23 @@
+module Riiif
+  module Region
+    # Represents an absolute specified region
+    class Absolute < Crop
+      # TODO: only kakadu needs image_info. So there's potenial to optimize by
+      # making image_info a proxy that fetches the info lazily when needed.
+      # @param [ImageInformation] image_info
+      # @param [String] x
+      # @param [String] y
+      # @param [String] width
+      # @param [String] height
+      def initialize(image_info, x, y, width, height)
+        @image_info = image_info
+        @offset_x = x.to_i
+        @offset_y = y.to_i
+        @width = width.to_i
+        @height = height.to_i
+      end
+
+      attr_reader :width, :height
+    end
+  end
+end
diff --git a/app/services/riiif/region/full.rb b/app/services/riiif/region/full.rb
new file mode 100644
index 0000000..554e196
--- /dev/null
+++ b/app/services/riiif/region/full.rb
@@ -0,0 +1,23 @@
+module Riiif
+  module Region
+    # Represents the image or region requested at its full size.
+    # This is a nil crop operation.
+    class Full < Crop
+      def initialize(image_info)
+        @image_info = image_info
+      end
+
+      # @return [NilClass] a region for imagemagick to decode
+      #                    the nil implies no cropping needed
+      def to_imagemagick
+        nil
+      end
+
+      # @return [NilClass] a region for kakadu to decode
+      #                    the nil implies no cropping needed
+      def to_kakadu
+        nil
+      end
+    end
+  end
+end
diff --git a/app/services/riiif/region/imagemagick/absolute_decoder.rb b/app/services/riiif/region/imagemagick/absolute_decoder.rb
deleted file mode 100644
index 5a797c9..0000000
--- a/app/services/riiif/region/imagemagick/absolute_decoder.rb
+++ /dev/null
@@ -1,21 +0,0 @@
-module Riiif
-  module Region
-    module Imagemagick
-      # decodes requested cooridnates into an imagemagick crop directive
-      class AbsoluteDecoder
-        def initialize(x, y, width, height)
-          @x = x
-          @y = y
-          @width = width
-          @height = height
-        end
-
-        # @return [String] a region for imagemagick to decode
-        #                  (appropriate for passing to the -crop parameter)
-        def decode
-          "#{@width}x#{@height}+#{@x}+#{@y}"
-        end
-      end
-    end
-  end
-end
diff --git a/app/services/riiif/region/imagemagick/full_decoder.rb b/app/services/riiif/region/imagemagick/full_decoder.rb
deleted file mode 100644
index 65b25e2..0000000
--- a/app/services/riiif/region/imagemagick/full_decoder.rb
+++ /dev/null
@@ -1,14 +0,0 @@
-module Riiif
-  module Region
-    module Imagemagick
-      # The image or region is not scaled, and is returned at its full size.
-      class FullDecoder
-        # @return [NilClass] a region for imagemagick to decode
-        #                    the nil implies no cropping needed
-        def decode
-          nil
-        end
-      end
-    end
-  end
-end
diff --git a/app/services/riiif/region/imagemagick/percentage_decoder.rb b/app/services/riiif/region/imagemagick/percentage_decoder.rb
deleted file mode 100644
index 9eeb3b6..0000000
--- a/app/services/riiif/region/imagemagick/percentage_decoder.rb
+++ /dev/null
@@ -1,33 +0,0 @@
-module Riiif
-  module Region
-    module Imagemagick
-      # decodes requested cooridnates into an imagemagick crop directive
-      class PercentageDecoder
-        def initialize(image_info, x, y, width, height)
-          @image_info = image_info
-          @x = x
-          @y = y
-          @width = width
-          @height = height
-        end
-
-        # Imagemagick can't do percentage offsets, so we have to calculate it
-        # @return [String] a region for imagemagick to decode
-        #                  (appropriate for passing to the -crop parameter)
-        def decode
-          "#{@width}%x#{@height}+#{offset_x}+#{offset_y}"
-        end
-
-        private
-
-          def offset_x
-            (@image_info.width * Integer(@x).to_f / 100).round
-          end
-
-          def offset_y
-            (@image_info.height * Integer(@y).to_f / 100).round
-          end
-      end
-    end
-  end
-end
diff --git a/app/services/riiif/region/imagemagick/square_decoder.rb b/app/services/riiif/region/imagemagick/square_decoder.rb
deleted file mode 100644
index 1e7c43f..0000000
--- a/app/services/riiif/region/imagemagick/square_decoder.rb
+++ /dev/null
@@ -1,25 +0,0 @@
-module Riiif
-  module Region
-    module Imagemagick
-      # decodes requested cooridnates into an imagemagick crop directive
-      class SquareDecoder
-        def initialize(image_info)
-          @image_info = image_info
-        end
-
-        # @return [String] a square region for imagemagick to decode
-        #                  (appropriate for passing to the -crop parameter)
-        def decode
-          min, max = [@image_info.width, @image_info.height].minmax
-
-          offset = (max - min) / 2
-          if @image_info.height >= @image_info.width
-            "#{min}x#{min}+0+#{offset}"
-          else
-            "#{min}x#{min}+#{offset}+0"
-          end
-        end
-      end
-    end
-  end
-end
diff --git a/app/services/riiif/region/percentage.rb b/app/services/riiif/region/percentage.rb
new file mode 100644
index 0000000..4b69a10
--- /dev/null
+++ b/app/services/riiif/region/percentage.rb
@@ -0,0 +1,68 @@
+module Riiif
+  module Region
+    # represents request cooridnates specified as percentage
+    class Percentage < Crop
+      def initialize(image_info, x, y, width, height)
+        @image_info = image_info
+        @x_pct = x
+        @y_pct = y
+        @width_pct = width
+        @height_pct = height
+      end
+
+      # From the Imagemagick docs:
+      #   The percentage symbol '%' can appear anywhere in a argument, and if
+      #   given will refer to both width and height numbers. It is a flag that
+      #   just declares that the 'image size' parts are a percentage fraction
+      #   of the images virtual canvas or page size. Offsets are always given
+      #   in pixels.
+      # @return [String] a region for imagemagick to decode
+      #                  (appropriate for passing to the -crop parameter)
+      def to_imagemagick
+        "#{@width_pct}%x#{@height_pct}+#{offset_x}+#{offset_y}"
+      end
+
+      def maintain_aspect_ratio?
+        @width_pct == @height_pct
+      end
+
+      private
+
+        # @param [String] n a percentage to convert
+        # @return [Float]
+        def percentage_to_fraction(n)
+          Integer(n).to_f / 100
+        end
+
+        # @return [Integer]
+        def offset_x
+          (@image_info.width * percentage_to_fraction(@x_pct)).round
+        end
+
+        # @return [Integer]
+        def offset_y
+          (@image_info.height * percentage_to_fraction(@y_pct)).round
+        end
+
+        # @return [Float]
+        def decimal_height
+          percentage_to_fraction(@height_pct)
+        end
+
+        # @return [Float]
+        def decimal_width
+          percentage_to_fraction(@width_pct)
+        end
+
+        # @return [Float]
+        def decimal_offset_y
+          percentage_to_fraction(@y_pct)
+        end
+
+        # @return [Float]
+        def decimal_offset_x
+          percentage_to_fraction(@x_pct)
+        end
+    end
+  end
+end
diff --git a/app/services/riiif/region/square.rb b/app/services/riiif/region/square.rb
new file mode 100644
index 0000000..cbed015
--- /dev/null
+++ b/app/services/riiif/region/square.rb
@@ -0,0 +1,45 @@
+module Riiif
+  module Region
+    # Represents requested square cooridnates
+    class Square < Crop
+      def initialize(image_info)
+        @image_info = image_info
+        @min, @max = [@image_info.width, @image_info.height].minmax
+        @offset = (@max - @min) / 2
+      end
+
+      # @return [String] a square region for imagemagick to decode
+      #                  (appropriate for passing to the -crop parameter)
+      def to_imagemagick
+        if @image_info.height >= @image_info.width
+          "#{height}x#{width}+0+#{@offset}"
+        else
+          "#{height}x#{width}+#{@offset}+0"
+        end
+      end
+
+      # @return [String] a region for kakadu to decode
+      #                  (appropriate for passing to the -region parameter)
+      def to_kakadu
+        # (top, left, height, width)
+        if @image_info.height >= @image_info.width
+          # Portrait
+          "\{#{decimal_height(@offset)},0\}," \
+          "\{#{decimal_height(height)},#{decimal_width(height)}\}"
+        else
+          # Landscape
+          "\{0,#{decimal_width(@offset)}\}," \
+          "\{#{decimal_height(width)},#{decimal_width(width)}\}"
+        end
+      end
+
+      def height
+        @min
+      end
+
+      def width
+        @min
+      end
+    end
+  end
+end
diff --git a/app/services/riiif/resize.rb b/app/services/riiif/resize.rb
new file mode 100644
index 0000000..ad08d4c
--- /dev/null
+++ b/app/services/riiif/resize.rb
@@ -0,0 +1,45 @@
+module Riiif
+  # Represents a resize operation
+  class Resize
+    attr_reader :image_info
+
+    # @return [Integer] the height in pixels
+    def height
+      image_info.height
+    end
+
+    # @return [Integer] the width in pixels
+    def width
+      image_info.width
+    end
+
+    # Should we reduce this image with KDU?
+    def reduce?
+      true
+    end
+
+    # This is used for a second resize by imagemagick after resizing
+    # by kdu.
+    # No need to scale most resize operations (only percent)
+    # @param [Integer] factor to scale by
+    # @return [Absolute] a copy of self if factor is zero.
+    def reduce(_factor)
+      dup
+    end
+
+    # @return [Integer] the reduction factor for this operation
+    def reduction_factor(max_factor = 5)
+      return nil unless reduce?
+      scale = [width.to_f / image_info.width,
+               height.to_f / image_info.height].min
+      factor = 0
+      raise "I don't know how to scale to #{scale}" if scale > 1
+      next_pct = 0.5
+      while scale <= next_pct && factor < max_factor
+        next_pct /= 2.0
+        factor += 1
+      end
+      factor
+    end
+  end
+end
diff --git a/app/services/riiif/size/absolute.rb b/app/services/riiif/size/absolute.rb
new file mode 100644
index 0000000..b1ff4b2
--- /dev/null
+++ b/app/services/riiif/size/absolute.rb
@@ -0,0 +1,39 @@
+module Riiif
+  module Size
+    # The width and height of the returned image are exactly w and h.
+    # The aspect ratio of the returned image may be different than the extracted
+    # region, resulting in a distorted image.
+    class Absolute < Resize
+      # @param [ImageInformation] info
+      # @param [String] width
+      # @param [String] height
+      def initialize(info, width, height)
+        @image_info = info
+        @width = width.to_i
+        @height = height.to_i
+      end
+
+      # @return [String] a resize directive for imagemagick to use
+      def to_imagemagick
+        "#{@width}x#{@height}!"
+      end
+
+      attr_reader :height, :width
+
+      # Reduce this if the aspect ratio of the image is maintained.
+      def reduce?
+        in_delta?(image_info.aspect_ratio, aspect_ratio, 0.001)
+      end
+
+      private
+
+        def aspect_ratio
+          width.to_f / height
+        end
+
+        def in_delta?(x1, x2, delta)
+          (x1 - x2).abs <= delta
+        end
+    end
+  end
+end
diff --git a/app/services/riiif/size/best_fit.rb b/app/services/riiif/size/best_fit.rb
new file mode 100644
index 0000000..b043c20
--- /dev/null
+++ b/app/services/riiif/size/best_fit.rb
@@ -0,0 +1,18 @@
+module Riiif
+  module Size
+    # The image content is scaled for the best fit such that the resulting width and
+    # height are less than or equal to the requested width and height.
+    class BestFit < Resize
+      def initialize(info, width, height)
+        @image_info = info
+        @width = width
+        @height = height
+      end
+
+      # @return [String] a resize directive for imagemagick to use
+      def to_imagemagick
+        "#{@width}x#{@height}"
+      end
+    end
+  end
+end
diff --git a/app/services/riiif/size/full.rb b/app/services/riiif/size/full.rb
new file mode 100644
index 0000000..5a4aa59
--- /dev/null
+++ b/app/services/riiif/size/full.rb
@@ -0,0 +1,17 @@
+module Riiif
+  module Size
+    # represents requested full size
+    class Full < Resize
+      # @return [NilClass] a size for imagemagick to decode
+      #                    the nil implies no resizing needed
+      def to_imagemagick
+        nil
+      end
+
+      # Should we reduce this image?
+      def reduce?
+        false
+      end
+    end
+  end
+end
diff --git a/app/services/riiif/size/height.rb b/app/services/riiif/size/height.rb
new file mode 100644
index 0000000..a71dfd6
--- /dev/null
+++ b/app/services/riiif/size/height.rb
@@ -0,0 +1,24 @@
+module Riiif
+  module Size
+    # The image or region should be scaled so that its height is exactly equal
+    # to the provided parameter, and the width will be a calculated value that
+    # maintains the aspect ratio of the extracted region
+    class Height < Resize
+      def initialize(info, height)
+        @image_info = info
+        @height = height.to_i
+      end
+
+      # @return [String] a resize directive for imagemagick to use
+      def to_imagemagick
+        "x#{@height}"
+      end
+
+      def width
+        height * image_info.width / image_info.height
+      end
+
+      attr_reader :height
+    end
+  end
+end
diff --git a/app/services/riiif/size/imagemagick/absolute_decoder.rb b/app/services/riiif/size/imagemagick/absolute_decoder.rb
deleted file mode 100644
index eb10a52..0000000
--- a/app/services/riiif/size/imagemagick/absolute_decoder.rb
+++ /dev/null
@@ -1,20 +0,0 @@
-module Riiif
-  module Size
-    module Imagemagick
-      # The width and height of the returned image are exactly w and h.
-      # The aspect ratio of the returned image may be different than the extracted
-      # region, resulting in a distorted image.
-      class AbsoluteDecoder
-        def initialize(width, height)
-          @width = width
-          @height = height
-        end
-
-        # @return [String] a resize directive for imagemagick to use
-        def decode
-          "#{@width}x#{@height}!"
-        end
-      end
-    end
-  end
-end
diff --git a/app/services/riiif/size/imagemagick/best_fit_decoder.rb b/app/services/riiif/size/imagemagick/best_fit_decoder.rb
deleted file mode 100644
index 86c9b6d..0000000
--- a/app/services/riiif/size/imagemagick/best_fit_decoder.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-module Riiif
-  module Size
-    module Imagemagick
-      # The image content is scaled for the best fit such that the resulting width and
-      # height are less than or equal to the requested width and height.
-      class BestFitDecoder
-        def initialize(width, height)
-          @width = width
-          @height = height
-        end
-
-        # @return [String] a resize directive for imagemagick to use
-        def decode
-          "#{@width}x#{@height}"
-        end
-      end
-    end
-  end
-end
diff --git a/app/services/riiif/size/imagemagick/full_decoder.rb b/app/services/riiif/size/imagemagick/full_decoder.rb
deleted file mode 100644
index d9e79ee..0000000
--- a/app/services/riiif/size/imagemagick/full_decoder.rb
+++ /dev/null
@@ -1,14 +0,0 @@
-module Riiif
-  module Size
-    module Imagemagick
-      # decodes requested size into an imagemagick resize directive
-      class FullDecoder
-        # @return [NilClass] a size for imagemagick to decode
-        #                    the nil implies no resizing needed
-        def decode
-          nil
-        end
-      end
-    end
-  end
-end
diff --git a/app/services/riiif/size/imagemagick/height_decoder.rb b/app/services/riiif/size/imagemagick/height_decoder.rb
deleted file mode 100644
index aa5a2f4..0000000
--- a/app/services/riiif/size/imagemagick/height_decoder.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-module Riiif
-  module Size
-    module Imagemagick
-      # The image or region should be scaled so that its height is exactly equal
-      # to the provided parameter, and the width will be a calculated value that
-      # maintains the aspect ratio of the extracted region
-      class HeightDecoder
-        def initialize(height)
-          @height = height
-        end
-
-        # @return [String] a resize directive for imagemagick to use
-        def decode
-          "x#{@height}"
-        end
-      end
-    end
-  end
-end
diff --git a/app/services/riiif/size/imagemagick/percent_decoder.rb b/app/services/riiif/size/imagemagick/percent_decoder.rb
deleted file mode 100644
index 115a7c1..0000000
--- a/app/services/riiif/size/imagemagick/percent_decoder.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-module Riiif
-  module Size
-    module Imagemagick
-      # The width and height of the returned image is scaled to n% of the width and height
-      # of the extracted region. The aspect ratio of the returned image is the same as that
-      # of the extracted region.
-      class PercentDecoder
-        def initialize(n)
-          @n = n
-        end
-
-        # @return [String] a resize directive for imagemagick to use
-        def decode
-          "#{@n}%"
-        end
-      end
-    end
-  end
-end
diff --git a/app/services/riiif/size/imagemagick/width_decoder.rb b/app/services/riiif/size/imagemagick/width_decoder.rb
deleted file mode 100644
index 4250c1a..0000000
--- a/app/services/riiif/size/imagemagick/width_decoder.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-module Riiif
-  module Size
-    module Imagemagick
-      # The image or region should be scaled so that its width is exactly equal
-      # to the provided parameter, and the height will be a calculated value that
-      # maintains the aspect ratio of the extracted region
-      class WidthDecoder
-        def initialize(width)
-          @width = width
-        end
-
-        # @return [String] a resize directive for imagemagick to use
-        def decode
-          @width.to_s
-        end
-      end
-    end
-  end
-end
diff --git a/app/services/riiif/size/percent.rb b/app/services/riiif/size/percent.rb
new file mode 100644
index 0000000..0e82be2
--- /dev/null
+++ b/app/services/riiif/size/percent.rb
@@ -0,0 +1,44 @@
+module Riiif
+  module Size
+    # The width and height of the returned image is scaled to n% of the width and height
+    # of the extracted region. The aspect ratio of the returned image is the same as that
+    # of the extracted region.
+    class Percent < Resize
+      def initialize(info, percentage)
+        @image_info = info
+        @percentage = percentage
+      end
+
+      attr_reader :percentage
+
+      # @return [String] a resize directive for imagemagick to use
+      def to_imagemagick
+        "#{percentage}%"
+      end
+
+      # @return [Integer] the height in pixels
+      def height
+        percent_of(image_info.height)
+      end
+
+      # @return [Integer] the width in pixels
+      def width
+        percent_of(image_info.width)
+      end
+
+      # @param [Integer] factor number of times to reduce by 1/2
+      def reduce(factor)
+        pct = percentage.to_f * 2**factor
+        Percent.new(image_info, pct)
+      end
+
+      private
+
+        # @param [Integer] value a value to convert to the percentage
+        # @return [Float]
+        def percent_of(value)
+          value * Integer(percentage).to_f / 100
+        end
+    end
+  end
+end
diff --git a/app/services/riiif/size/width.rb b/app/services/riiif/size/width.rb
new file mode 100644
index 0000000..ac3307f
--- /dev/null
+++ b/app/services/riiif/size/width.rb
@@ -0,0 +1,24 @@
+module Riiif
+  module Size
+    # The image or region should be scaled so that its width is exactly equal
+    # to the provided parameter, and the height will be a calculated value that
+    # maintains the aspect ratio of the extracted region
+    class Width < Resize
+      def initialize(info, width)
+        @image_info = info
+        @width = width.to_i
+      end
+
+      # @return [String] a resize directive for imagemagick to use
+      def to_imagemagick
+        @width.to_s
+      end
+
+      attr_reader :width
+
+      def height
+        width * image_info.height / image_info.width
+      end
+    end
+  end
+end
diff --git a/app/transformers/riiif/abstract_transformer.rb b/app/transformers/riiif/abstract_transformer.rb
new file mode 100644
index 0000000..a096b90
--- /dev/null
+++ b/app/transformers/riiif/abstract_transformer.rb
@@ -0,0 +1,30 @@
+module Riiif
+  # Transforms an image using a backend
+  class AbstractTransformer
+    # @param path [String] The path of the source image file
+    # @param image_info [ImageInformation] information about the source
+    # @param [Transformation] transformation
+    def self.transform(path, image_info, transformation)
+      new(path, image_info, transformation).transform
+    end
+
+    def initialize(path, image_info, transformation)
+      @path = path
+      @image_info = image_info
+      @transformation = transformation
+    end
+
+    attr_reader :path, :image_info, :transformation
+
+    def transform
+      execute(command_builder.command)
+    end
+
+    def command_builder
+      @command_builder ||= command_factory.new(path, image_info, transformation)
+    end
+
+    delegate :execute, to: Riiif::CommandRunner
+    private :execute
+  end
+end
diff --git a/app/transformers/riiif/imagemagick_transformer.rb b/app/transformers/riiif/imagemagick_transformer.rb
new file mode 100644
index 0000000..5bebe8c
--- /dev/null
+++ b/app/transformers/riiif/imagemagick_transformer.rb
@@ -0,0 +1,8 @@
+module Riiif
+  # Transforms an image using Imagemagick
+  class ImagemagickTransformer < AbstractTransformer
+    def command_factory
+      ImagemagickCommandFactory
+    end
+  end
+end
diff --git a/app/transformers/riiif/kakadu_transformer.rb b/app/transformers/riiif/kakadu_transformer.rb
new file mode 100644
index 0000000..fde9d7e
--- /dev/null
+++ b/app/transformers/riiif/kakadu_transformer.rb
@@ -0,0 +1,39 @@
+module Riiif
+  # Transforms an image using Kakadu
+  class KakaduTransformer < AbstractTransformer
+    def command_factory
+      KakaduCommandFactory
+    end
+
+    def transform
+      with_tempfile do |file_name|
+        execute(command_builder.command(file_name))
+        post_process(file_name, command_builder.reduction_factor)
+      end
+    end
+
+    def with_tempfile
+      Tempfile.open(['riiif-intermediate', '.bmp']) do |f|
+        yield f.path
+      end
+    end
+
+    # The data we get back from kdu_expand is a bmp and we need to change it
+    # to the requested format by calling Imagemagick.
+    def post_process(intermediate_file, reduction_factor)
+      # Calculate a new set of transforms with respect to reduction_factor
+      transformation = if reduction_factor
+                         self.transformation.without_crop(image_info).reduce(reduction_factor)
+                       else
+                         self.transformation.without_crop(image_info)
+                       end
+      Riiif::File.new(intermediate_file).extract(transformation, image_info)
+    end
+
+    private
+
+      def tmp_path
+        @link_path ||= LinkNameService.create
+      end
+  end
+end
diff --git a/lib/riiif.rb b/lib/riiif.rb
index bd74c12..467e199 100644
--- a/lib/riiif.rb
+++ b/lib/riiif.rb
@@ -18,7 +18,10 @@ class ImageNotFoundError < Error; end
   # This error is raised when Riiif can't convert an image
   class ConversionError < Error; end
 
-  Transformation = Struct.new(:crop, :size, :quality, :rotation, :format)
   mattr_accessor :not_found_image # the image to use when a lookup fails
   mattr_accessor :unauthorized_image # the image to use when a user doesn't have access
+
+  def self.kakadu_enabled?
+    Engine.config.kakadu_enabled
+  end
 end
diff --git a/lib/riiif/engine.rb b/lib/riiif/engine.rb
index c08ff99..d163c8d 100644
--- a/lib/riiif/engine.rb
+++ b/lib/riiif/engine.rb
@@ -5,8 +5,9 @@ class Engine < ::Rails::Engine
     # How long to cache the tiles for.
     config.cache_duration_in_days = 3
 
-    config.action_dispatch.rescue_responses.merge!(
-      'Riiif::ImageNotFoundError' => :not_found
-    )
+    config.action_dispatch.rescue_responses['Riiif::ImageNotFoundError'] = :not_found
+
+    # Set to true to use kdu for jp2000 source images
+    config.kakadu_enabled = false
   end
 end
diff --git a/spec/models/riiif/image_spec.rb b/spec/models/riiif/image_spec.rb
index ff914a6..33e2cd3 100644
--- a/spec/models/riiif/image_spec.rb
+++ b/spec/models/riiif/image_spec.rb
@@ -15,11 +15,14 @@
 
   describe 'happy path' do
     before do
-      expect(subject.file).to receive(:execute)
-        .with("convert -quality 85 -sampling-factor 4:2:0 -strip #{filename} jpg:-")
-        .and_return('imagedata')
+      allow(image.info_service).to receive(:call).and_return({})
     end
+
     it 'renders' do
+      expect(Riiif::CommandRunner).to receive(:execute)
+        .with("convert -quality 85 -sampling-factor 4:2:0 -strip #{filename} jpg:-")
+        .and_return('imagedata')
+
       expect(subject.render('size' => 'full', format: 'jpg')).to eq 'imagedata'
     end
   end
diff --git a/spec/models/riiif/transformation_spec.rb b/spec/models/riiif/transformation_spec.rb
new file mode 100644
index 0000000..c462459
--- /dev/null
+++ b/spec/models/riiif/transformation_spec.rb
@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Riiif::Transformation do
+  subject(:transformation) do
+    Riiif::Transformation.new(region,
+                              size,
+                              quality,
+                              rotation,
+                              fmt)
+  end
+
+  let(:region) { Riiif::Region::Full.new(image_info) }
+  let(:size) { Riiif::Size::Percent.new(image_info, 20) }
+  let(:quality) { nil }
+  let(:rotation) { nil }
+  let(:fmt) { nil }
+  let(:image_info) { double('Image info', height: 4381, width: 6501) }
+
+  describe 'reduce' do
+    subject { transformation.reduce(factor) }
+    context 'when reduced by 2' do
+      let(:factor) { 2 }
+      let(:size) { Riiif::Size::Percent.new(image_info, 20) }
+
+      it 'downsamples the size' do
+        expect(subject.size).to be_kind_of Riiif::Size::Percent
+        expect(subject.size.percentage).to eq 80.0
+      end
+    end
+  end
+
+  describe 'without_crop' do
+    let(:region) { Riiif::Region::Absolute.new(image_info, 5, 6, 7, 8) }
+
+    subject { transformation.without_crop(image_info) }
+    it 'nullifies the crop' do
+      expect(subject.crop).to be_kind_of Riiif::Region::Full
+    end
+  end
+end
diff --git a/spec/services/riiif/imagemagick_command_factory_spec.rb b/spec/services/riiif/imagemagick_command_factory_spec.rb
index 6e29030..02c8879 100644
--- a/spec/services/riiif/imagemagick_command_factory_spec.rb
+++ b/spec/services/riiif/imagemagick_command_factory_spec.rb
@@ -2,13 +2,15 @@
 
 RSpec.describe Riiif::ImagemagickCommandFactory do
   let(:path) { 'foo.tiff' }
+  let(:info) { double('foo') }
 
-  describe '.build' do
-    subject { described_class.build(path, transformation) }
+  describe '.command' do
+    subject { instance.command }
+    let(:instance) { described_class.new(path, info, transformation) }
 
     let(:transformation) do
-      Riiif::Transformation.new('region',
-                                'size',
+      Riiif::Transformation.new(Riiif::Region::Full.new(info),
+                                Riiif::Size::Full.new,
                                 'quality',
                                 'rotation',
                                 format)
diff --git a/spec/services/riiif/kakadu_command_factory_spec.rb b/spec/services/riiif/kakadu_command_factory_spec.rb
new file mode 100644
index 0000000..851fecf
--- /dev/null
+++ b/spec/services/riiif/kakadu_command_factory_spec.rb
@@ -0,0 +1,85 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Riiif::KakaduCommandFactory do
+  subject(:instance) { described_class.new(path, info, transformation) }
+
+  let(:info) { double(:info) }
+  let(:path) { 'foo.jp2' }
+  let(:region) { Riiif::Region::Full.new(info) }
+  let(:size) { Riiif::Size::Full.new }
+  let(:quality) { nil }
+  let(:rotation) { nil }
+  let(:fmt) { nil }
+
+  let(:transformation) do
+    Riiif::Transformation.new(region,
+                              size,
+                              quality,
+                              rotation,
+                              fmt)
+  end
+
+  describe '#command' do
+    subject { instance.command '/tmp/bar.bmp' }
+
+    context 'with a full size image' do
+      it { is_expected.to eq 'kdu_expand -quiet -i foo.jp2 -num_threads 4 -o /tmp/bar.bmp' }
+    end
+  end
+
+  describe '#region' do
+    subject { instance.send(:region) }
+    let(:info) { double(height: 300, width: 300) }
+
+    context 'with a full' do
+      it { is_expected.to be nil }
+    end
+
+    context 'with absolute' do
+      let(:region) { Riiif::Region::Absolute.new(info, 25, 75, 150, 100) }
+      it { is_expected.to eq ' -region "{0.25,0.08333333333333333},{0.3333333333333333,0.5}"' }
+    end
+
+    context 'with a square' do
+      let(:region) { Riiif::Region::Square.new(info) }
+      it { is_expected.to eq ' -region "{0.0,0},{1.0,1.0}"' }
+    end
+
+    context 'with a percentage' do
+      let(:region) { Riiif::Region::Percentage.new(info, 20, 30, 40, 50) }
+      it { is_expected.to eq ' -region "{0.3,0.2},{0.5,0.4}"' }
+    end
+  end
+
+  describe '#reduction_factor' do
+    subject { instance.send(:reduction_factor) }
+
+    let(:info) { Riiif::ImageInformation.new(300, 300) }
+
+    context 'for a full size image' do
+      it { is_expected.to eq nil }
+    end
+
+    context 'when the aspect ratio is maintined for absolute' do
+      let(:size) { Riiif::Size::Absolute.new(info, 145, 145) }
+      it { is_expected.to eq 1 }
+    end
+
+    context 'when the aspect ratio is not-maintined' do
+      let(:size) { Riiif::Size::Absolute.new(info, 100, 145) }
+      it { is_expected.to eq nil }
+    end
+
+    context 'when aspect ratio is maintained for 45 pct' do
+      let(:size) { Riiif::Size::Percent.new(info, 45) }
+      it { is_expected.to eq 1 }
+    end
+
+    context 'when aspect ratio is maintained for 20 pct' do
+      let(:size) { Riiif::Size::Percent.new(info, 20) }
+      it { is_expected.to eq 2 }
+    end
+  end
+end
diff --git a/spec/services/riiif/region/absolute_spec.rb b/spec/services/riiif/region/absolute_spec.rb
new file mode 100644
index 0000000..19e3b9d
--- /dev/null
+++ b/spec/services/riiif/region/absolute_spec.rb
@@ -0,0 +1,17 @@
+require 'spec_helper'
+
+RSpec.describe Riiif::Region::Absolute do
+  let(:image_info) { double }
+
+  context 'when initialized with strings' do
+    let(:instance) { described_class.new(image_info, '5', '15', '50', '100') }
+
+    it 'casts height to an integer' do
+      expect(instance.height).to eq 100
+    end
+
+    it 'casts width to an integer' do
+      expect(instance.width).to eq 50
+    end
+  end
+end
diff --git a/spec/services/riiif/size/absolute_spec.rb b/spec/services/riiif/size/absolute_spec.rb
new file mode 100644
index 0000000..4c5ef03
--- /dev/null
+++ b/spec/services/riiif/size/absolute_spec.rb
@@ -0,0 +1,17 @@
+require 'spec_helper'
+
+RSpec.describe Riiif::Size::Absolute do
+  let(:image_info) { double }
+
+  context 'when initialized with strings' do
+    let(:instance) { described_class.new(image_info, '50', '100') }
+
+    it 'casts height to an integer' do
+      expect(instance.height).to eq 100
+    end
+
+    it 'casts width to an integer' do
+      expect(instance.width).to eq 50
+    end
+  end
+end
diff --git a/spec/services/riiif/size/height_spec.rb b/spec/services/riiif/size/height_spec.rb
new file mode 100644
index 0000000..71b167f
--- /dev/null
+++ b/spec/services/riiif/size/height_spec.rb
@@ -0,0 +1,13 @@
+require 'spec_helper'
+
+RSpec.describe Riiif::Size::Height do
+  let(:image_info) { double }
+
+  context 'when initialized with strings' do
+    let(:instance) { described_class.new(image_info, '50') }
+
+    it 'casts height to an integer' do
+      expect(instance.height).to eq 50
+    end
+  end
+end
diff --git a/spec/services/riiif/size/width_spec.rb b/spec/services/riiif/size/width_spec.rb
new file mode 100644
index 0000000..6c7562b
--- /dev/null
+++ b/spec/services/riiif/size/width_spec.rb
@@ -0,0 +1,13 @@
+require 'spec_helper'
+
+RSpec.describe Riiif::Size::Width do
+  let(:image_info) { double }
+
+  context 'when initialized with strings' do
+    let(:instance) { described_class.new(image_info, '50') }
+
+    it 'casts height to an integer' do
+      expect(instance.width).to eq 50
+    end
+  end
+end
diff --git a/spec/transformers/riiif/kakadu_transformer_spec.rb b/spec/transformers/riiif/kakadu_transformer_spec.rb
new file mode 100644
index 0000000..9fcd43e
--- /dev/null
+++ b/spec/transformers/riiif/kakadu_transformer_spec.rb
@@ -0,0 +1,143 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Riiif::KakaduTransformer do
+  subject(:instance) { described_class.new(path, image_info, transformation) }
+
+  let(:image_info) { Riiif::ImageInformation.new(6501, 4381) }
+  let(:path) { 'baseball.jp2' }
+  let(:region) { Riiif::Region::Full.new(image_info) }
+  let(:size) { Riiif::Size::Full.new }
+  let(:quality) { nil }
+  let(:rotation) { nil }
+  let(:fmt) { 'jpg' }
+
+  let(:transformation) do
+    Riiif::Transformation.new(region,
+                              size,
+                              quality,
+                              rotation,
+                              fmt)
+  end
+
+  describe '#transform' do
+    let(:image_data) { double }
+
+    subject(:transform) { instance.transform }
+
+    before do
+      allow(instance).to receive(:with_tempfile).and_yield('/tmp/foo.bmp')
+    end
+
+    context 'resize and region' do
+      # This is the validator test for size_region
+      let(:size) { Riiif::Size::Absolute.new(image_info, 38, 38) }
+      let(:region) { Riiif::Region::Absolute.new(image_info, 200, 100, 100, 100) }
+
+      let(:image_info) { Riiif::ImageInformation.new(1000, 1000) }
+
+      it 'calls the Imagemagick transform' do
+        expect(Riiif::CommandRunner).to receive(:execute)
+          .with('kdu_expand -quiet -i baseball.jp2 -num_threads 4 ' \
+                '-region "{0.1,0.2},{0.1,0.1}" -reduce 4 -o /tmp/foo.bmp')
+        expect(Riiif::CommandRunner).to receive(:execute)
+          .with('convert -resize 38x38! -quality 85 -sampling-factor 4:2:0 -strip /tmp/foo.bmp jpg:-')
+        transform
+      end
+    end
+
+    context 'when reduction_factor is 0' do
+      let(:reduction_factor) { 0 }
+      context 'and the size is full' do
+        it 'calls the Imagemagick transform' do
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('kdu_expand -quiet -i baseball.jp2 -num_threads 4 -o /tmp/foo.bmp')
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('convert -quality 85 -sampling-factor 4:2:0 -strip /tmp/foo.bmp jpg:-')
+          transform
+        end
+      end
+
+      context 'and size is a width' do
+        let(:size) { Riiif::Size::Width.new(image_info, 651) }
+        let(:image_info) { Riiif::ImageInformation.new(1000, 1000) }
+
+        it 'calls the Imagemagick transform' do
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('kdu_expand -quiet -i baseball.jp2 -num_threads 4 -o /tmp/foo.bmp')
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('convert -resize 651 -quality 85 -sampling-factor 4:2:0 -strip /tmp/foo.bmp jpg:-')
+          transform
+        end
+      end
+
+      context 'and size is a height' do
+        let(:size) { Riiif::Size::Height.new(image_info, 581) }
+        let(:image_info) { Riiif::ImageInformation.new(1000, 1000) }
+
+        it 'calls the Imagemagick transform' do
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('kdu_expand -quiet -i baseball.jp2 -num_threads 4 -o /tmp/foo.bmp')
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('convert -resize x581 -quality 85 -sampling-factor 4:2:0 -strip /tmp/foo.bmp jpg:-')
+          transform
+        end
+      end
+    end
+
+    context 'when reduction_factor is 1' do
+      let(:reduction_factor) { 1 }
+
+      context 'and size is a Percent' do
+        let(:size) { Riiif::Size::Percent.new(image_info, 30) }
+
+        it 'calls the Imagemagick transform' do
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('kdu_expand -quiet -i baseball.jp2 -num_threads 4 -reduce 1 -o /tmp/foo.bmp')
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('convert -resize 60.0% -quality 85 -sampling-factor 4:2:0 -strip /tmp/foo.bmp jpg:-')
+          transform
+        end
+      end
+
+      context 'and size is a width' do
+        let(:size) { Riiif::Size::Width.new(image_info, 408) }
+        let(:image_info) { Riiif::ImageInformation.new(1000, 1000) }
+
+        it 'calls the Imagemagick transform' do
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('kdu_expand -quiet -i baseball.jp2 -num_threads 4 -reduce 1 -o /tmp/foo.bmp')
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('convert -resize 408 -quality 85 -sampling-factor 4:2:0 -strip /tmp/foo.bmp jpg:-')
+          transform
+        end
+      end
+
+      context 'and size is a height' do
+        let(:size) { Riiif::Size::Height.new(image_info, 481) }
+        let(:image_info) { Riiif::ImageInformation.new(1000, 1000) }
+
+        it 'calls the Imagemagick transform' do
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('kdu_expand -quiet -i baseball.jp2 -num_threads 4 -reduce 1 -o /tmp/foo.bmp')
+          expect(Riiif::CommandRunner).to receive(:execute)
+            .with('convert -resize x481 -quality 85 -sampling-factor 4:2:0 -strip /tmp/foo.bmp jpg:-')
+          transform
+        end
+      end
+    end
+
+    context 'when reduction_factor is 2' do
+      let(:size) { Riiif::Size::Percent.new(image_info, 20) }
+      let(:reduction_factor) { 2 }
+      it 'calls the Imagemagick transform' do
+        expect(Riiif::CommandRunner).to receive(:execute)
+          .with('kdu_expand -quiet -i baseball.jp2 -num_threads 4 -reduce 2 -o /tmp/foo.bmp')
+        expect(Riiif::CommandRunner).to receive(:execute)
+          .with('convert -resize 80.0% -quality 85 -sampling-factor 4:2:0 -strip /tmp/foo.bmp jpg:-')
+        transform
+      end
+    end
+  end
+end