ShowEdgeDetectorDlg example for Delphi

procedure TForm1.ShowEdgeDetectorDlg1Click(Sender: TObject); 
var
   nRet: L_INT; 
begin
   LEADDlgImgEffect1.DlgFlags:= DLG_EDGEDETECTOR_SHOW_PREVIEW Or
                                 DLG_EDGEDETECTOR_SHOW_TOOL_ZOOMLEVEL; 

   LEADDlgImgEffect1.LEADImage:= LEADImage1; 

   nRet:= LEADDlgImgEffect1.ShowEdgeDetectorDlg ( Self ); 
   if ( nRet = SUCCESS_DLG_OK ) then
   begin
      LEADImage1.EdgeDetector (LEADDlgImgEffect1.Threshold, 
                                LEADDlgImgEffect1.EdgeDetectionFilterType); 
   end; 
end;