Kakadu support

.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

Gemfile

@@ -1,4 +1,5 @@
 source 'https://rubygems.org'
 
+gem 'byebug'
 # Specify your gem's dependencies in riiif.gemspec
 gemspec

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

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
 

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

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

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

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

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

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

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

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