diff --git a/Makefile b/Makefile
index aa7f871..3d80368 100644
--- a/Makefile
+++ b/Makefile
@@ -4,4 +4,6 @@ test :
 	testrb `find tests -name '*.rb'`
 
 test-coverage :
-	rcov -x '\/jruby\/lib\/' -x '\/tests\/data\/' `find tests -name '*.rb'`
\ No newline at end of file
+	rcov -x '\/jruby\/lib\/' -x '\/tests\/data\/' `find tests -name '*.rb'`
+	sed 's#<td class="left_align"><a href="<script>.html"><script></a></td>#<td></td>#' coverage/index.html > coverage/index.html.new
+	mv coverage/index.html.new coverage/index.html
diff --git a/classes/InputFilter.rb b/classes/InputFilter.rb
index 97de32f..de852e5 100644
--- a/classes/InputFilter.rb
+++ b/classes/InputFilter.rb
@@ -1,4 +1,4 @@
-require 'filter'
+require File.dirname(__FILE__) + '/Filter.rb'
 
 class InputFilter < Filter
   OutputFilename = "tmp.png"
diff --git a/classes/SVGToTempBitmap.rb b/classes/SVGToTempBitmap.rb
new file mode 100644
index 0000000..8c498d6
--- /dev/null
+++ b/classes/SVGToTempBitmap.rb
@@ -0,0 +1,102 @@
+require File.dirname(__FILE__) + '/InputFilter.rb'
+
+class SVGToTempBitmap < InputFilter
+  include PrintHandling
+
+  #
+  # select which build method to use based on the number of provided images.
+  #
+  def build(input)
+    (input.instance_of? Array) ? multiple(input) : single(input)
+  end
+
+  #
+  # process a single input file, possibly splitting it into two output files if it's a spread
+  #
+  def single(input)
+    filename = Dir.pwd + '/' + OutputFilename
+    inkscape(input, filename)
+    @cleanup << filename
+
+    if @config['spread']
+      targets = build_spread(filename)
+      @cleanup.concat targets
+      return targets
+    end
+
+    return filename
+  end
+
+  def build_spread(filename)
+    width, height = get_dimensions(filename)
+    targets = []
+
+    [ [ "left", 0 ], [ "right", width / 2 ] ].each do |side, offset|
+      target = filename + "-#{side}.png"
+      command = [
+        "\"#{filename}\"",
+        "-gravity Northwest",
+        "-crop #{width/2}x#{height}+#{offset}+0",
+        "+repage",
+        "\"#{target}\""
+      ]
+
+      convert(command)
+
+      targets << target
+    end
+
+    return targets
+  end
+
+  #
+  # combine multiple input files onto a single page-sized canvas.
+  # images are added left-to-right and top-to-bottom starting from the top-left of the page.
+  # leave a grid square blank by passing the filename "/blank".
+  #
+  def multiple(files)
+    if @config['spread']; raise "Spreads and grids combined do not make sense"; end
+
+    width, height = @config['grid'].split("x").collect { |f| f.to_f }
+    joined_files = []
+
+    page_width, page_height = calculate_page_size
+
+    grid_width = page_width / width
+    grid_height = page_height / height
+
+    0.upto(files.length - 1) do |i|
+      x = i % width
+      y = (i / width).floor
+
+      if files[i].split('/').last != "blank"
+        tmp_svg_output = OutputFilename + "-#{i}.png"
+        inkscape(Dir.pwd + '/' + files[i], tmp_svg_output)
+
+        joined_files << [ tmp_svg_output, x, y ]
+        @cleanup << tmp_svg_output
+      end
+    end
+
+    command = [
+      "-size #{page_width}x#{page_height}",
+      "xc:white"
+    ]
+
+    joined_files.each do |file, x, y|
+      image_width, image_height = get_dimensions(file)
+
+      x_offset = (grid_width - image_width) / 2
+      y_offset = (grid_height - image_height) / 2
+
+      command << "\"#{file}\" -geometry +#{x * grid_width + x_offset}+#{y * grid_height + y_offset} -composite"
+    end
+
+    command << OutputFilename
+
+    convert(command)
+
+    @cleanup << OutputFilename
+    OutputFilename
+  end
+end
diff --git a/minicomic-backend.rb b/minicomic-backend.rb
index dab0d51..adbecc6 100755
--- a/minicomic-backend.rb
+++ b/minicomic-backend.rb
@@ -7,102 +7,6 @@ Dir[File.dirname(__FILE__) + "/classes/*.rb"].each do |file|
   require file
 end
 
-class SVGToTempBitmap < InputFilter
-  include PrintHandling
-
-  #
-  # select which build method to use based on the number of provided images.
-  #
-  def build(input)
-    (input.instance_of? Array) ? multiple(input) : single(input)
-  end
-
-  #
-  # process a single input file, possibly splitting it into two output files if it's a spread
-  #
-  def single(input)
-    filename = Dir.pwd + '/' + OutputFilename
-    inkscape(input, filename)
-    @cleanup << filename
-
-    if @config['spread']
-      width, height = get_dimensions(filename)
-      targets = []
-
-      [ [ "left", 0 ], [ "right", width / 2 ] ].each do |side, offset|
-        target = filename + "-#{side}.png"
-        command = [
-          "\"#{filename}\"",
-          "-gravity Northwest",
-          "-crop #{width/2}x#{height}+#{offset}+0",
-          "+repage",
-          "\"#{target}\""
-        ]
-
-        convert(command)
-
-        targets << target
-        @cleanup << target
-      end
-
-      return targets
-    end
-
-    return filename
-  end
-
-  #
-  # combine multiple input files onto a single page-sized canvas.
-  # images are added left-to-right and top-to-bottom starting from the top-left of the page.
-  # leave a grid square blank by passing the filename "/blank".
-  #
-  def multiple(files)
-    if @config['spread']; raise "Spreads and grids combined do not make sense"; end
-
-    width, height = @config['grid'].split("x").collect { |f| f.to_f }
-    joined_files = []
-
-    page_width, page_height = calculate_page_size
-
-    grid_width = page_width / width
-    grid_height = page_height / height
-
-    0.upto(files.length - 1) do |i|
-      x = i % width
-      y = (i / width).floor
-
-      if files[i].split('/').last != "blank"
-        tmp_svg_output = OutputFilename + "-#{i}.png"
-        inkscape(Dir.pwd + '/' + files[i], tmp_svg_output)
-
-        joined_files << [ tmp_svg_output, x, y ]
-        @cleanup << tmp_svg_output
-      end
-    end
-
-    command = [
-      "-size #{page_width}x#{page_height}",
-      "xc:white"
-    ]
-
-    joined_files.each do |file, x, y|
-      image_width, image_height = get_dimensions(file)
-
-      x_offset = (grid_width - image_width) / 2
-      y_offset = (grid_height - image_height) / 2
-
-      command << "\"#{file}\" -geometry +#{x * grid_width + x_offset}+#{y * grid_height + y_offset} -composite"
-    end
-
-    command << OutputFilename
-
-    convert(command)
-
-    @cleanup << OutputFilename
-    OutputFilename
-  end
-end
-
 #
 # Process an input file for the Web
 #
diff --git a/tests/TestSVGToTempBitmap.rb b/tests/TestSVGToTempBitmap.rb
new file mode 100644
index 0000000..f2b203d
--- /dev/null
+++ b/tests/TestSVGToTempBitmap.rb
@@ -0,0 +1,28 @@
+require 'rubygems'
+require 'test/unit'
+require 'fakefs/safe'
+require File.dirname(__FILE__) + '/../classes/SVGToTempBitmap.rb'
+
+class TestSVGToTempBitmap < Test::Unit::TestCase
+  def setup
+    @filter = SVGToTempBitmap.new
+  end
+
+  def test_build
+    [
+      [ "", :single ],
+      [ [], :multiple ]
+    ].each do |input, expected_method|
+      @filter.expects(expected_method).with(input)
+      @filter.build(input)
+    end
+  end
+
+  def test_build_spread
+    @filter.stubs(:get_dimensions).with('filename').returns([50, 75])
+    @filter.expects(:convert).with(['"filename"', '-gravity Northwest', '-crop 25x75+0+0', '+repage', '"filename-left.png"'])
+    @filter.expects(:convert).with(['"filename"', '-gravity Northwest', '-crop 25x75+25+0', '+repage', '"filename-right.png"'])
+
+    assert_equal [ 'filename-left.png', 'filename-right.png' ], @filter.build_spread('filename')
+  end
+end