ContourFilter example for C++ Builder

   LEADRasterProcess* pRasterProc= NULL;

     CoCreateInstance(CLSID_LEADRasterProcess, NULL, CLSCTX_ALL, IID_ILEADRasterProcess, (void**)&pRasterProc);

   pRasterProc->ContourFilter (LEADRasterView1->Raster,
                            20, 35, 5, CONTOUR_APPROX_COLOR);
   pRasterProc-> Release( );