Creating annotation toolbar error

I'm converting code from version 13.0 to version 14.5. Old code was written by someone else:

public LTANNLib.LEADRasterAnnToolBarClass m_TheAnnToolbar = null;

private void ViewToolbar_Click(object sender, System.EventArgs e, string fileFullPath)
{
 LEAD.Drawing.Bitmap userBmp = new LEAD.Drawing.Bitmap(GetType(), "user.bmp");
 LTRASTERLib.LEADRasterFactoryClass factory = new LTRASTERLib.LEADRasterFactoryClass();
 object rasterObj = factory.CreateObject("LEADRaster.LEADRaster",
     "LEADTOOLS OCX Copyright (c) 1991-2001 LEAD Technologies, Inc.");
 LTRASTERLib.LEADRasterClass rasterTemp;
 try
 {
     rasterTemp = (LTRASTERLib.LEADRasterClass)rasterObj; //error here
     IntPtr hBitmap = userBmp.GetHbitmap();
     Graphics g = CreateGraphics();
     IntPtr hDC = g.GetHdc();
     rasterTemp.SetDDB(hDC.ToInt32(), hBitmap.ToInt32(), 0);
     g.ReleaseHdc(hDC);
     g.Dispose();
     DeleteObject(hBitmap);
     m_TheAnnToolbar.set_ButtonTool(m_TheAnnToolbar.ButtonCount,
         LTANNLib.AnnToolConstants.ANN_TOOL_USER_FIRST);
     m_TheAnnToolbar.set_ButtonBitmapUp(m_TheAnnToolbar.ButtonCount, rasterTemp.Bitmap);
     m_TheAnnToolbar.set_ButtonBitmapUp(m_TheAnnToolbar.ButtonCount, rasterTemp.Bitmap);
     m_TheAnnToolbar.set_ButtonBitmapDown(m_TheAnnToolbar.ButtonCount, rasterTemp.Bitmap);
     m_TheAnnToolbar.set_ButtonToolTipTextID(m_TheAnnToolbar.ButtonCount, -1);
     m_TheAnnToolbar.set_ButtonToolTipText(m_TheAnnToolbar.ButtonCount, "User Defined");
     m_TheAnnToolbar.ButtonCount++;
 }
 catch (System.Exception ex)
 {
  throw ex;
 }
}
[DllImport("gdi32")]
public static extern int DeleteObject(IntPtr hObject);

I've changed one line of code from:
LEAD.Drawing.Bitmap userBmp = new LEAD.Drawing.Bitmap(GetType(), "user.bmp");
To:
Bitmap userBmp = new Bitmap(GetType(), "user.bmp");

When I run it, it didn't error that line but it throw exception from:
rasterTemp = (LTRASTERLib.LEADRasterClass)rasterObj;

Here is an error detail:
Cannot create LeadRasterClass object window. ---> System.InvalidCastException: Unable to cast COM object of type 'System.__ComObject' to class type 'LTRASTERLib.LEADRasterClass'. COM components that enter the CLR and do not support IProvideClassInfo or that do not have any interop assembly registered will be wrapped in the __ComObject type. Instances of this type cannot be cast to any other class; however they can be cast to interfaces as long as the underlying COM component supports QueryInterface calls for the IID of the interface.
   at UserControl.ViewToolbar_Click(Object sender, EventArgs e, String fileFullPath)

I was unable to find information of LTRASTERLib.LEADRasterClass from help file. I don't know what is it.

1. Could you point me out where to look for in help file?

2. It was fine with version 13.0. Is there any additional/change that I should do for version 14.5?

Please help,