diff --git a/build/build.ps1 b/build/build.ps1
index e4c74bbe3..57ed576ce 100644
--- a/build/build.ps1
+++ b/build/build.ps1
@@ -152,7 +152,7 @@ task Run-Coverage -depends Build-Tests {
 		$CoverageOutputPath = Join-Path $TEST_RESULTS "$($_)_Coverage.xml"
 		
 		Write-Host "Running code coverage on project $_"
-		$coverageFilter = "-filter:+[*]* -[FluentAssertions*]* -[ImageProcessor]*Common.Exceptions -[ImageProcessor]*ImageFactory -[ImageProcessor.UnitTests]* -[ImageProcessor.Web.UnitTests]*"
+		$coverageFilter = "-filter:+[*]* -[FluentAssertions*]* -[ImageProcessor]*Common.Exceptions -[ImageProcessor.UnitTests]* -[ImageProcessor.Web.UnitTests]*"
 		& $OPENCOVER_EXE -register:user -target:$NUNIT_EXE -targetargs:"$TestDdlPath /noshadow /nologo" -targetdir:$TestDllFolder -output:$CoverageOutputPath $coverageFilter
 		
 		Write-Host "Transforming coverage results file to HTML"
diff --git a/src/ImageProcessor.UnitTests/AssertionHelpers.cs b/src/ImageProcessor.UnitTests/AssertionHelpers.cs
new file mode 100644
index 000000000..205480f9e
--- /dev/null
+++ b/src/ImageProcessor.UnitTests/AssertionHelpers.cs
@@ -0,0 +1,56 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="AssertionHelpers.cs" company="James South">
+//   Copyright (c) James South.
+//   Licensed under the Apache License, Version 2.0.
+// </copyright>
+// --------------------------------------------------------------------------------------------------------------------
+namespace ImageProcessor.UnitTests
+{
+    using System.Drawing;
+    using System.Drawing.Imaging;
+    using System.Linq;
+    using System.IO;
+    using NUnit.Framework;
+    using FluentAssertions;
+
+    /// <summary>
+    /// Provides helpers for asserting
+    /// </summary>
+    public class AssertionHelpers
+    {
+        /// <summary>
+        /// Asserts that two images are identical
+        /// </summary>
+        /// <param name="expected">The expected result</param>
+        /// <param name="tested">The tested image</param>
+        public static void AssertImagesAreIdentical(Image expected, Image tested, string because, params string[] becauseArgs)
+        {
+            ToByteArray(expected).SequenceEqual(ToByteArray(tested)).Should().BeTrue(because, becauseArgs);
+        }
+
+        /// <summary>
+        /// Asserts that two images are different
+        /// </summary>
+        /// <param name="expected">The not-expected result</param>
+        /// <param name="tested">The tested image</param>
+        public static void AssertImagesAreDifferent(Image expected, Image tested, string because, params string[] becauseArgs)
+        {
+            ToByteArray(expected).SequenceEqual(ToByteArray(tested)).Should().BeFalse(because, becauseArgs);
+        }
+
+        /// <summary>
+        /// Converts an image to a byte array
+        /// </summary>
+        /// <param name="imageIn">The image to convert</param>
+        /// <param name="format">The format to use</param>
+        /// <returns>An array of bytes representing the image</returns>
+        public static byte[] ToByteArray(Image imageIn)
+        {
+            using (MemoryStream ms = new MemoryStream())
+            {
+                imageIn.Save(ms, ImageFormat.Jpeg);
+                return ms.ToArray();
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/ImageProcessor.UnitTests/ImageFactoryUnitTests.cs b/src/ImageProcessor.UnitTests/ImageFactoryUnitTests.cs
index c2a5e4e41..222771bc6 100644
--- a/src/ImageProcessor.UnitTests/ImageFactoryUnitTests.cs
+++ b/src/ImageProcessor.UnitTests/ImageFactoryUnitTests.cs
@@ -126,7 +126,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.Alpha(50);
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the alpha operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the alpha operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -140,7 +140,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.Brightness(50);
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the brightness operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the brightness operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -154,7 +154,7 @@ namespace ImageProcessor.UnitTests
             imageFactory.Load(@"Images\text.png");
             Image original = (Image)imageFactory.Image.Clone();
             imageFactory.BackgroundColor(Color.Yellow);
-            AssertImagesAreDifferent(original, imageFactory.Image, "because the background color operation should have been applied on {0}", imageFactory.ImagePath);
+            AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the background color operation should have been applied on {0}", imageFactory.ImagePath);
         }
 
         /// <summary>
@@ -167,7 +167,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.Contrast(50);
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the contrast operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the contrast operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -181,7 +181,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.Saturation(50);
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the saturation operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the saturation operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -195,7 +195,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.Tint(Color.FromKnownColor(KnownColor.AliceBlue));
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the tint operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the tint operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -209,7 +209,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.Vignette(Color.FromKnownColor(KnownColor.AliceBlue));
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the vignette operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the vignette operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -229,7 +229,7 @@ namespace ImageProcessor.UnitTests
                     Position = new Point(10, 10),
                     Text = "Lorem ipsum dolor"
                 });
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the watermark operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the watermark operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -243,7 +243,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.GaussianBlur(5);
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the blur operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the blur operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -257,7 +257,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.GaussianBlur(new GaussianLayer { Sigma = 10, Size = 5, Threshold = 2 });
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the layered blur operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the layered blur operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -271,7 +271,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.GaussianSharpen(5);
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the sharpen operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the sharpen operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -285,7 +285,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.GaussianSharpen(new GaussianLayer { Sigma = 10, Size = 5, Threshold = 2 });
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the layered sharpen operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the layered sharpen operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -316,9 +316,9 @@ namespace ImageProcessor.UnitTests
                 foreach (IMatrixFilter filter in filters)
                 {
                     imageFactory.Filter(filter);
-                    AssertImagesAreDifferent(original, imageFactory.Image, "because the filter operation should have been applied on {0}", imageFactory.ImagePath);
+                    AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the filter operation should have been applied on {0}", imageFactory.ImagePath);
                     imageFactory.Reset();
-                    AssertImagesAreIdentical(original, imageFactory.Image, "because the image should be reset");
+                    AssertionHelpers.AssertImagesAreIdentical(original, imageFactory.Image, "because the image should be reset");
                 }
             }
         }
@@ -333,7 +333,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.RoundedCorners(new RoundedCornerLayer(5));
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the rounded corners operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the rounded corners operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -363,7 +363,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.Crop(new Rectangle(0, 0, MaxSize, MaxSize));
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the crop operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the crop operation should have been applied on {0}", imageFactory.ImagePath);
 
                 imageFactory.Image.Width.Should().Be(MaxSize, "because the cropped image should be {0}x{0}", MaxSize);
                 imageFactory.Image.Height.Should().Be(MaxSize, "because the cropped image should be {0}x{0}", MaxSize);
@@ -381,7 +381,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.Crop(new CropLayer(0, 0, MaxSize, MaxSize, CropMode.Pixels));
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the layered crop operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the layered crop operation should have been applied on {0}", imageFactory.ImagePath);
 
                 imageFactory.Image.Width.Should().Be(MaxSize, "because the cropped image should be {0}x{0}", MaxSize);
                 imageFactory.Image.Height.Should().Be(MaxSize, "because the cropped image should be {0}x{0}", MaxSize);
@@ -398,14 +398,14 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.Flip(true);
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the vertical flip operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the vertical flip operation should have been applied on {0}", imageFactory.ImagePath);
                 imageFactory.Image.Width.Should().Be(original.Width, "because the dimensions should not have changed");
                 imageFactory.Image.Height.Should().Be(original.Height, "because the dimensions should not have changed");
                 imageFactory.Reset();
-                AssertImagesAreIdentical(original, imageFactory.Image, "because the image should be reset");
+                AssertionHelpers.AssertImagesAreIdentical(original, imageFactory.Image, "because the image should be reset");
 
                 imageFactory.Flip();
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the horizontal flip operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the horizontal flip operation should have been applied on {0}", imageFactory.ImagePath);
                 imageFactory.Image.Width.Should().Be(original.Width, "because the dimensions should not have changed");
                 imageFactory.Image.Height.Should().Be(original.Height, "because the dimensions should not have changed");
             }
@@ -469,13 +469,13 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.Hue(90);
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the hue operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the hue operation should have been applied on {0}", imageFactory.ImagePath);
 
                 imageFactory.Reset();
-                AssertImagesAreIdentical(original, imageFactory.Image, "because the image should be reset");
+                AssertionHelpers.AssertImagesAreIdentical(original, imageFactory.Image, "because the image should be reset");
 
                 imageFactory.Hue(116, true);
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the hue+rotate operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the hue+rotate operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -489,7 +489,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.Pixelate(8);
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the pixelate operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the pixelate operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -519,7 +519,7 @@ namespace ImageProcessor.UnitTests
             {
                 Image original = (Image)imageFactory.Image.Clone();
                 imageFactory.ReplaceColor(Color.White, Color.Black, 90);
-                AssertImagesAreDifferent(original, imageFactory.Image, "because the color replace operation should have been applied on {0}", imageFactory.ImagePath);
+                AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the color replace operation should have been applied on {0}", imageFactory.ImagePath);
             }
         }
 
@@ -549,9 +549,9 @@ namespace ImageProcessor.UnitTests
                 foreach (IEdgeFilter filter in filters)
                 {
                     imageFactory.DetectEdges(filter);
-                    AssertImagesAreDifferent(original, imageFactory.Image, "because the edge operation should have been applied on {0}", imageFactory.ImagePath);
+                    AssertionHelpers.AssertImagesAreDifferent(original, imageFactory.Image, "because the edge operation should have been applied on {0}", imageFactory.ImagePath);
                     imageFactory.Reset();
-                    AssertImagesAreIdentical(original, imageFactory.Image, "because the image should be reset");
+                    AssertionHelpers.AssertImagesAreIdentical(original, imageFactory.Image, "because the image should be reset");
                 }
             }
         }
@@ -623,40 +623,5 @@ namespace ImageProcessor.UnitTests
 
             return imagesFactories;
         }
-
-        /// <summary>
-        /// Asserts that two images are identical
-        /// </summary>
-        /// <param name="expected">The expected result</param>
-        /// <param name="tested">The tested image</param>
-        private void AssertImagesAreIdentical(Image expected, Image tested, string because, params string[] becauseArgs)
-        {
-            ToByteArray(expected).SequenceEqual(ToByteArray(tested)).Should().BeTrue(because, becauseArgs);
-        }
-
-        /// <summary>
-        /// Asserts that two images are different
-        /// </summary>
-        /// <param name="expected">The not-expected result</param>
-        /// <param name="tested">The tested image</param>
-        private void AssertImagesAreDifferent(Image expected, Image tested, string because, params string[] becauseArgs)
-        {
-            ToByteArray(expected).SequenceEqual(ToByteArray(tested)).Should().BeFalse(because, becauseArgs);
-        }
-
-        /// <summary>
-        /// Converts an image to a byte array
-        /// </summary>
-        /// <param name="imageIn">The image to convert</param>
-        /// <param name="format">The format to use</param>
-        /// <returns>An array of bytes representing the image</returns>
-        public static byte[] ToByteArray(Image imageIn)
-        {
-            using (MemoryStream ms = new MemoryStream())
-            {
-                imageIn.Save(ms, ImageFormat.Jpeg);
-                return ms.ToArray();
-            }
-        }
     }
 }
\ No newline at end of file
diff --git a/src/ImageProcessor.UnitTests/ImageProcessor.UnitTests.csproj b/src/ImageProcessor.UnitTests/ImageProcessor.UnitTests.csproj
index 761706d6b..db53cdb0d 100644
--- a/src/ImageProcessor.UnitTests/ImageProcessor.UnitTests.csproj
+++ b/src/ImageProcessor.UnitTests/ImageProcessor.UnitTests.csproj
@@ -54,6 +54,7 @@
     <Reference Include="System.Xml.Linq" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="AssertionHelpers.cs" />
     <Compile Include="Configuration\ImageProcessorBootrapperTests.cs" />
     <Compile Include="ImageFactoryUnitTests.cs">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
@@ -61,6 +62,8 @@
     <Compile Include="Extensions\DoubleExtensionsUnitTests.cs" />
     <Compile Include="Extensions\IntegerExtensionsUnitTests.cs" />
     <Compile Include="Imaging\ColorUnitTests.cs" />
+    <Compile Include="Imaging\CropLayerUnitTests.cs" />
+    <Compile Include="Imaging\FastBitmapUnitTests.cs" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
   <ItemGroup>
diff --git a/src/ImageProcessor.UnitTests/Imaging/CropLayerUnitTests.cs b/src/ImageProcessor.UnitTests/Imaging/CropLayerUnitTests.cs
new file mode 100644
index 000000000..01c03c745
--- /dev/null
+++ b/src/ImageProcessor.UnitTests/Imaging/CropLayerUnitTests.cs
@@ -0,0 +1,36 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="CropLayerUnitTests.cs" company="James South">
+//   Copyright (c) James South.
+//   Licensed under the Apache License, Version 2.0.
+// </copyright>
+// --------------------------------------------------------------------------------------------------------------------
+namespace ImageProcessor.UnitTests.Imaging
+{
+    using ImageProcessor.Imaging;
+    using FluentAssertions;
+    using NUnit.Framework;
+
+    /// <summary>
+    /// Test harness for the <see cref="CropLayer" /> class
+    /// </summary>
+    [TestFixture]
+    public class CropLayerUnitTests
+    {
+        /// <summary>
+        /// Tests that the constructor saves the provided data
+        /// </summary>
+        [Test]
+        [TestCase(10.5F, 11.2F, 15.6F, 108.9F, CropMode.Percentage)]
+        [TestCase(15.1F, 20.7F, 65.8F, 156.7F, CropMode.Pixels)]
+        public void ConstructorSavesData(float left, float top, float right, float bottom, CropMode mode)
+        {
+            CropLayer cl = new CropLayer(left, top, right, bottom, mode);
+
+            cl.Left.Should().Be(left);
+            cl.Top.Should().Be(top);
+            cl.Right.Should().Be(right);
+            cl.Bottom.Should().Be(bottom);
+            cl.CropMode.Should().Be(mode);
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/ImageProcessor.UnitTests/Imaging/FastBitmapUnitTests.cs b/src/ImageProcessor.UnitTests/Imaging/FastBitmapUnitTests.cs
new file mode 100644
index 000000000..13c51a80b
--- /dev/null
+++ b/src/ImageProcessor.UnitTests/Imaging/FastBitmapUnitTests.cs
@@ -0,0 +1,62 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="FastBitmapUnitTests.cs" company="James South">
+//   Copyright (c) James South.
+//   Licensed under the Apache License, Version 2.0.
+// </copyright>
+// --------------------------------------------------------------------------------------------------------------------
+namespace ImageProcessor.UnitTests.Imaging
+{
+    using System.Drawing;
+    using FluentAssertions;
+    using ImageProcessor.Imaging;
+    using NUnit.Framework;
+
+    /// <summary>
+    /// Test harness for the <see cref="ImageProcessor.Imaging.FastBitmap"/> class
+    /// </summary>
+    [TestFixture]
+    public class FastBitmapUnitTests
+    {
+        /// <summary>
+        /// Tests that the bitmap's data is read by the fast bitmap
+        /// </summary>
+        /// <param name="file">The path to the test file</param>
+        [Test]
+        [TestCase(@"Images\format-Penguins.jpg")]
+        [TestCase(@"Images\format-Penguins.png")]
+        public void BitmapIsRead(string file)
+        {
+            Bitmap bmp = new Bitmap(file);
+
+            using (FastBitmap fbmp = new FastBitmap(bmp))
+            {
+                fbmp.Width.Should().Be(bmp.Width, "because the bitmap should have been read");
+                fbmp.Height.Should().Be(bmp.Height, "because the bitmap should have been read");
+            }
+        }
+
+        /// <summary>
+        /// Tests that modifications on the fast bitmap's bitmap are actually done
+        /// </summary>
+        /// <param name="file">The path to the test file</param>
+        [Test]
+        [TestCase(@"Images\format-Penguins.jpg")]
+        [TestCase(@"Images\format-Penguins.png")]
+        public void FastBitmapModificationsAreApplied(string file)
+        {
+            Bitmap bmp = new Bitmap(file);
+            Bitmap original = (Bitmap)bmp.Clone();
+
+            using (FastBitmap fbmp = new FastBitmap(bmp))
+            {
+                // draw a pink diagonal line
+                for (int i = 0; i < 10; i++)
+                {
+                    fbmp.SetPixel(i, i, Color.Pink);
+                }
+            }
+
+            AssertionHelpers.AssertImagesAreDifferent(original, bmp, "because modifying the fast bitmap should have modified the original bitmap");
+        }
+    }
+}