private void pf__rxsiRotate_Callback()
        {
            //pf_Trace(_rxsiRotate.Value.ToString());

            double tag = _rxsiRotate.Value;

            _rxivc.SetRotateCenter(RxGeom.GetAngleToRadian(tag));
            _rxivc.BoundsDrawUpdate();

            pf_ImageHeightUpdate();
            pf_ImageWidthUpdate();
        }