diff --git a/src/ImageProcessor/ImageProcessor.csproj b/src/ImageProcessor/ImageProcessor.csproj
index 4bb47105a..a2d74b754 100644
--- a/src/ImageProcessor/ImageProcessor.csproj
+++ b/src/ImageProcessor/ImageProcessor.csproj
@@ -78,10 +78,11 @@
     <Compile Include="Imaging\Colors\YCbCrColor.cs" />
     <Compile Include="Imaging\EdgeDetection\ConvolutionFilter.cs" />
     <Compile Include="Imaging\EdgeDetection\IEdgeFilter.cs" />
+    <Compile Include="Imaging\EdgeDetection\KirschEdgeFilter.cs" />
     <Compile Include="Imaging\EdgeDetection\ScharrEdgeFilter.cs" />
     <Compile Include="Imaging\EdgeDetection\RobertsCrossEdgeFilter.cs" />
     <Compile Include="Imaging\EdgeDetection\PrewittEdgeFilter.cs" />
-    <Compile Include="Imaging\EdgeDetection\CostellaEdgeFilter.cs" />
+    <Compile Include="Imaging\EdgeDetection\KayyaliEdgeFilter.cs" />
     <Compile Include="Imaging\EdgeDetection\SobelEdgeFilter.cs" />
     <Compile Include="Imaging\FastBitmap.cs">
       <SubType>Code</SubType>
diff --git a/src/ImageProcessor/Imaging/EdgeDetection/CostellaEdgeFilter.cs b/src/ImageProcessor/Imaging/EdgeDetection/CostellaEdgeFilter.cs
deleted file mode 100644
index fe0cb4c9a..000000000
--- a/src/ImageProcessor/Imaging/EdgeDetection/CostellaEdgeFilter.cs
+++ /dev/null
@@ -1,68 +0,0 @@
-// --------------------------------------------------------------------------------------------------------------------
-// <copyright file="CostellaEdgeFilter.cs" company="James South">
-//   Copyright (c) James South.
-//   Licensed under the Apache License, Version 2.0.
-// </copyright>
-// <summary>
-//   The Costella operator filter.
-//   <see href="http://johncostella.com/edgedetect/" />
-// </summary>
-// --------------------------------------------------------------------------------------------------------------------
-
-namespace ImageProcessor.Imaging.EdgeDetection
-{
-    /// <summary>
-    /// The Costella operator filter.
-    /// <see href="http://johncostella.com/edgedetect/"/>
-    /// </summary>
-    public class CostellaEdgeFilter : IEdgeFilter
-    {
-        /// <summary>
-        /// Gets the horizontal gradient operator.
-        /// </summary>
-        public double[,] HorizontalGradientOperator
-        {
-            get
-            {
-                //return new double[,] 
-                //{ { -1, -1, -1, -1, -1, }, 
-                //  { -1, -1, -1, -1, -1, }, 
-                //  { -1, -1, 24, -1, -1, }, 
-                //  { -1, -1, -1, -1, -1, }, 
-                //  { -1, -1, -1, -1, -1  }, };
-                return new double[,] 
-                { 
-                    { -1, -3, 0, 3, 1 }, 
-                    { -1, -3, 0, 3, 1 }, 
-                    { -1, -3, 0, 3, 1 }, 
-                    { -1, -3, 0, 3, 1 }, 
-                    { -1, -3, 0, 3, 1 } 
-                };
-            }
-        }
-
-        /// <summary>
-        /// Gets the vertical gradient operator.
-        /// </summary>
-        public double[,] VerticalGradientOperator
-        {
-            get
-            {
-                //return new double[,] 
-                //{ { -1, -1, -1, -1, -1, }, 
-                //  { -1, -1, -1, -1, -1, }, 
-                //  { -1, -1, 24, -1, -1, }, 
-                //  { -1, -1, -1, -1, -1, }, 
-                //  { -1, -1, -1, -1, -1  }, };
-                return new double[,]
-                { 
-                    { 1, 1, 1, 1, 1 }, 
-                    { 3, 3, 3, 3, 3 }, 
-                    { 0, 0, 0, 0, 0 }, 
-                    { -3, -3, -3, -3, -3 }, 
-                    { -1, -1, -1, -1, -1 } 
-                };
-            }
-        }
-    }
-}
diff --git a/src/ImageProcessor/Imaging/EdgeDetection/KayyaliEdgeFilter.cs b/src/ImageProcessor/Imaging/EdgeDetection/KayyaliEdgeFilter.cs
new file mode 100644
index 000000000..cbedae2a6
--- /dev/null
+++ b/src/ImageProcessor/Imaging/EdgeDetection/KayyaliEdgeFilter.cs
@@ -0,0 +1,52 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="KayyaliEdgeFilter.cs" company="James South">
+//   Copyright (c) James South.
+//   Licensed under the Apache License, Version 2.0.
+// </copyright>
+// <summary>
+//   The Kayyali operator filter.
+//   <see href="http://edgedetection.webs.com/" />
+// </summary>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace ImageProcessor.Imaging.EdgeDetection
+{
+    /// <summary>
+    /// The Kayyali operator filter.
+    /// <see href="http://edgedetection.webs.com/"/>
+    /// </summary>
+    public class KayyaliEdgeFilter : IEdgeFilter
+    {
+        /// <summary>
+        /// Gets the horizontal gradient operator.
+        /// </summary>
+        public double[,] HorizontalGradientOperator
+        {
+            get
+            {
+                return new double[,] 
+                {
+                    { 6, 0, -6 }, 
+                    { 0, 0, 0 }, 
+                    { -6, 0, 6 }
+                };
+            }
+        }
+
+        /// <summary>
+        /// Gets the vertical gradient operator.
+        /// </summary>
+        public double[,] VerticalGradientOperator
+        {
+            get
+            {
+                return new double[,] 
+                {
+                    { -6, 0, 6 }, 
+                    { 0, 0, 0 }, 
+                    { 6, 0, -6 }
+                };
+            }
+        }
+    }
+}
diff --git a/src/ImageProcessor/Imaging/EdgeDetection/KirschEdgeFilter.cs b/src/ImageProcessor/Imaging/EdgeDetection/KirschEdgeFilter.cs
new file mode 100644
index 000000000..3a57d13a4
--- /dev/null
+++ b/src/ImageProcessor/Imaging/EdgeDetection/KirschEdgeFilter.cs
@@ -0,0 +1,52 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="KirschEdgeFilter.cs" company="James South">
+//   Copyright (c) James South.
+//   Licensed under the Apache License, Version 2.0.
+// </copyright>
+// <summary>
+//   The Kirsch operator filter.
+//   <see href="http://en.wikipedia.org/wiki/Kirsch_operator" />
+// </summary>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace ImageProcessor.Imaging.EdgeDetection
+{
+    /// <summary>
+    /// The Kirsch operator filter.
+    /// <see href="http://en.wikipedia.org/wiki/Kirsch_operator"/>
+    /// </summary>
+    public class KirschEdgeFilter : IEdgeFilter
+    {
+        /// <summary>
+        /// Gets the horizontal gradient operator.
+        /// </summary>
+        public double[,] HorizontalGradientOperator
+        {
+            get
+            {
+                return new double[,] 
+                {
+                    { 5, 5, 5 }, 
+                    { -3, 0, -3 }, 
+                    { -3, -3, -3 }
+                };
+            }
+        }
+
+        /// <summary>
+        /// Gets the vertical gradient operator.
+        /// </summary>
+        public double[,] VerticalGradientOperator
+        {
+            get
+            {
+                return new double[,] 
+                { 
+                    { 5, -3, -3 }, 
+                    { 5,  0, -3 }, 
+                    { 5, -3, -3 } 
+                };
+            }
+        }
+    }
+}
diff --git a/src/ImageProcessor/Imaging/FastBitmap.cs b/src/ImageProcessor/Imaging/FastBitmap.cs
index db8d80643..97af88356 100644
--- a/src/ImageProcessor/Imaging/FastBitmap.cs
+++ b/src/ImageProcessor/Imaging/FastBitmap.cs
@@ -156,12 +156,12 @@ namespace ImageProcessor.Imaging
         /// <returns>The <see cref="System.Drawing.Color"/> at the given pixel.</returns>
         public Color GetPixel(int x, int y)
         {
-            if ((x < 0) || (x > this.width))
+            if ((x < 0) || (x >= this.width))
             {
                 throw new ArgumentOutOfRangeException("x", "Value cannot be less than zero or greater than the bitmap width.");
             }
 
-            if ((y < 0) || (y > this.height))
+            if ((y < 0) || (y >= this.height))
             {
                 throw new ArgumentOutOfRangeException("y", "Value cannot be less than zero or greater than the bitmap height.");
             }
diff --git a/src/ImageProcessor/Settings.StyleCop b/src/ImageProcessor/Settings.StyleCop
index 9e50dcc98..0a9f862fa 100644
--- a/src/ImageProcessor/Settings.StyleCop
+++ b/src/ImageProcessor/Settings.StyleCop
@@ -6,6 +6,7 @@
       <Value>ddd</Value>
       <Value>dllimport</Value>
       <Value>gps</Value>
+      <Value>Kayyali</Value>
       <Value>mmmm</Value>
       <Value>orig</Value>
       <Value>Scharr</Value>
diff --git a/src/ImageProcessorConsole/Program.cs b/src/ImageProcessorConsole/Program.cs
index ddfbdd383..07243551b 100644
--- a/src/ImageProcessorConsole/Program.cs
+++ b/src/ImageProcessorConsole/Program.cs
@@ -77,7 +77,7 @@ namespace ImageProcessorConsole
                             //.Constrain(size)
                             //.ReplaceColor(Color.FromArgb(255, 1, 107, 165), Color.FromArgb(255, 1, 165, 13), 80)
                             .Resize(layer)
-                            .DetectEdges(new PrewittEdgeFilter(), false)
+                            .DetectEdges(new KirschEdgeFilter())
                             //.Filter(MatrixFilters.Comic)
                             //.Filter(MatrixFilters.HiSatch)
                             //.Pixelate(8)