C#

using a1;
using a2;
namespace BasicLogic
{ class Form1:Form
   {
     ..
   }
...
}

File a1.cs
namespace a1
{...
}

File a2.cs 
namespace a2
{...
}

/// <summary>
       /// Resets the game, including putting all the players on the Start square.
       /// This requires updating what is displayed in the GUI,
       /// as well as resetting the attrtibutes of HareAndTortoiseGame .
       /// This method is used by both the Reset button and
       /// when a new value is chosen in the Number of Players ComboBox.
       /// Pre:  none.
       /// Post: the form displays the game in the same state as when the program first starts
       ///       (except that any user names that the player has entered are not reset).
       /// </summary>

/// <summary>
        /// At several places in the program's code, it is necessary to update the GUI board,
        /// so that player's tokens (or "pieces") are removed from their old squares
        /// or added to their new squares. E.g. when all players are moved back to the Start.
        ///
        /// For each of the players, this method is to use the GetSquareNumberOfPlayer method to find out
        /// which square number the player is on currently, then use the SquareControlAt method
        /// to find the corresponding SquareControl, and then update that SquareControl so that it
        /// knows whether the player is on that square or not.
        ///
        /// Moving all players from their old to their new squares requires this method to be called twice:
        /// once with the parameter typeOfGuiUpdate set to RemovePlayer, and once with it set to AddPlayer.
        /// In between those two calls, the players locations must be changed by using one or more methods
        /// in the HareAndTortoiseGame class. Otherwise, you won't see any change on the screen.
        ///
        /// Because this method moves ALL players, it should NOT be used when animating a SINGLE player's
        /// movements from square to square.
        ///
        ///
        /// Post: the GUI board is updated to match the locations of all Players objects.
        /// </summary>
        /// <param name="typeOfGuiUpdate">Specifies whether all the players are being removed
        /// from their old squares or added to their new squares</param>
        private void UpdatePlayersGuiLocations(TypeOfGuiUpdate typeOfGuiUpdate) {



            //##################### Code needs to be added here. ############################################################


            RefreshBoardTablePanelLayout(); // Must be the last line in this method. DO NOT put it inside a loop.
        }// end UpdatePlayersGuiLocations

Image<Gray, Byte> img1 = new Image<Gray, Byte>("C:\\image1.png"); 
Image<Gray, Byte> img2 = new Image<Gray, Byte>("C:\\image2.png"); 
Image<Gray, Byte> img3 = img2 - img1; //Here the difference is applied.