diff --git a/MarketData/MarketDataLib/CNNProcessing/ImageHelper.cs b/MarketData/MarketDataLib/CNNProcessing/ImageHelper.cs
index 3f479ac..51d4efe 100644
--- a/MarketData/MarketDataLib/CNNProcessing/ImageHelper.cs
+++ b/MarketData/MarketDataLib/CNNProcessing/ImageHelper.cs
@@ -408,26 +408,30 @@ namespace MarketData.CNNProcessing
         }
       } 
 
+      /// <summary>
+      /// Fills the rectangle with the specified color
+      /// </summary>
+      /// <param name="color"></param>
       public void Fill(SKColor color)
       {
         SKRectI rect = new SKRectI(0, 0, Width, Height); // x, y, width, height
         bitmap.Erase(color, rect);
-      }     
-
-      /// <summary>
-      /// DrawPoint - With translation
-      /// </summary>
-      /// <param name="color"></param>
-      /// <param name="drawPoint"></param>
-      public void DrawPoint(SKColor color,SKPoint drawPoint)
-      {
-        Validate();
-        using SKCanvas canvas = new SKCanvas(bitmap);
-        canvas.Clear();
-        SKPoint txPoint = pointMapping.MapPoint(drawPoint);
-        canvas.DrawPoint(drawPoint, color);
       }
 
+			/// <summary>
+			/// DrawPoint - With translation
+			/// </summary>
+			/// <param name="color"></param>
+			/// <param name="drawPoint"></param>
+			public void DrawPoint(SKColor color, SKPoint drawPoint)
+			{
+				Validate();
+				using SKCanvas canvas = new SKCanvas(bitmap);
+				canvas.Clear();
+				SKPoint txPoint = pointMapping.MapPoint(drawPoint);
+				canvas.DrawPoint(drawPoint, color);
+			}
+
       /// <summary>
       /// DrawPoint - with given strokeWidth and translation 
       /// </summary>
diff --git a/MarketData/MarketDataLib/CNNProcessing/PointMapping.cs b/MarketData/MarketDataLib/CNNProcessing/PointMapping.cs
index 41bfa9e..8774caa 100755
--- a/MarketData/MarketDataLib/CNNProcessing/PointMapping.cs
+++ b/MarketData/MarketDataLib/CNNProcessing/PointMapping.cs
@@ -33,13 +33,23 @@ namespace MarketData.CNNProcessing
       XScalingFactor = pointMapping.XScalingFactor;
       YScalingFactor = pointMapping.YScalingFactor;
     }
-    
-// MapPoint will both scale the given point and translate the given point from an upper left origin system to a bottom left origin system
+
+    /// <summary>
+    /// MapPoint will both scale the given point and translate the given point from an upper left origin system to a bottom left origin system
+    /// Because of the scaling factor (XScalingFactor and YScalingFactor) it is possible for the resulting X,Y values to be rounded out of range.
+    /// To remedy this we perform a boundary check of the X,Y points against the extents and set them to those extents if they are out of range.
+    /// </summary>
+    /// <param name="sourcePoint"></param>
+    /// <returns></returns>
     public SKPoint MapPoint(SKPoint sourcePoint)
     {
-      SKPoint mappedPoint = new SKPoint((int)((sourcePoint.X - XDataExtentMin) * XScalingFactor), (int)(Height - ((sourcePoint.Y - YDataExtentMin) * YScalingFactor)));
+      SKPoint mappedPoint = new SKPoint((int)((sourcePoint.X - XDataExtentMin) * XScalingFactor), (int)((Height - 1) - ((sourcePoint.Y - YDataExtentMin) * YScalingFactor)));
       mappedPoint.X += (int)XMargin;   // offset by the xMargin
       mappedPoint.Y -= (int)YMargin;   // offset by the yMargin
+      if (mappedPoint.X > XDataExtent) mappedPoint.X = (int)XDataExtent;  // constrain X to XDataExtent
+      if (mappedPoint.Y > YDataExtent) mappedPoint.Y = (int)YDataExtent;  // constrain Y to YDataExtent
+      if (mappedPoint.X < XDataExtentMin) mappedPoint.X = (int)XDataExtentMin; // constrain X to XDataExtentMin
+      if (mappedPoint.Y < YDataExtentMin) mappedPoint.Y = (int)YDataExtentMin; // constrain Y to YDataExtentMin
       return mappedPoint;
     }
 // TranslatePoint will only translate the given point from an upper left origin system to a bottom left origin system
@@ -48,7 +58,8 @@ namespace MarketData.CNNProcessing
       SKPoint mappedPoint=new SKPoint((int)sourcePoint.X,(int)(Height-sourcePoint.Y-1));
       return mappedPoint;
     }
-    public double Width{get;private set;}
+    
+    public double Width { get; private set; }
     public double Height{get;private set;}
     public double XDataExtent{get;private set;}
     public double XDataExtentMin{get;private set;}