Minor bug fix for MotionDetection Example.

Emgu.CV.Example/MotionDetection/Form1.cs

@@ -82,6 +82,7 @@ namespace MotionDetection
 
          //create the motion image 
          Mat motionImage = new Mat(motionMask.Size.Height, motionMask.Size.Width, DepthType.Cv8U, 3);
+         motionImage.SetTo(new MCvScalar(0));
          //display the motion pixels in blue (first channel)
          //motionImage[0] = motionMask;
          CvInvoke.InsertChannel(motionMask, motionImage, 0);

Emgu.CV/Cvb/CvBlobDetector.cs

@@ -25,11 +25,8 @@ namespace Emgu.CV.Cvb
       private uint[,] _data;
       private GCHandle _dataHandle;
 
-#if NETFX_CORE 
-      private static int _sizeOfUInt32 = Marshal.SizeOf<UInt32>();
-#else
-      private static int _sizeOfUInt32 = Marshal.SizeOf(typeof(UInt32));
-#endif
+      private static int _sizeOfUInt32 = Toolbox.SizeOf<UInt32>();
+
       /// <summary>
       /// Detect blobs from input image.
       /// </summary>

Emgu.Util/Toolbox.cs

@@ -105,8 +105,23 @@ namespace Emgu.Util
          using (StringReader stringReader = new StringReader(xmlString))
             return (T) (new XmlSerializer(typeof(T))).Deserialize(stringReader);
       }
-#endregion
+      #endregion
+#endif
+
+      /// <summary>
+      /// Similar to Marshal.SizeOf function
+      /// </summary>
+      /// <typeparam name="T">The type</typeparam>
+      /// <returns>The size of T in bytes</returns>
+      public static int SizeOf<T>()
+      {
+#if NETFX_CORE
+         return Marshal.SizeOf<T>();
+#else
+         return Marshal.SizeOf(typeof(T));
 #endif
+      }
+
       /*
       /// <summary>
       /// Read a text file to an array of string, each row are separated using by the input separator