for (int i = 0; i < _keyPoints->Count; i++)
   {
   key = &(_keyPoints->Data[i]);
   hobj = _paint->AddNewObject();
   radius = ceil(key->scale * SiftParams.InitSigma);  // initial sigma
   _paint->ObjPenColor[hobj] = clAqua;
   _paint->ObjKind[hobj] = iekELLIPSE;
   _paint->ObjTop[hobj]  =  key->y - radius + addY;
   _paint->ObjLeft[hobj] =  key->x - radius + addX;
   _paint->ObjWidth[hobj] =  radius*2;
   _paint->ObjHeight[hobj] = radius*2;
   }