uses ComObj;
      .....

   procedure TForm1.Button1Click(Sender: TObject);
   var
     NVcomp : Variant;
     retVal : Integer;
   begin
     NVcomp := CreateOleObject('PDFcompress.Neevia');

     NVcomp.CI := 'jpx';
     NVcomp.CQ := 75;

     NVcomp.GI := 'jpx';
     NVcomp.GQ := 75;

     NVcomp.MI := 'jbig2l';
     NVcomp.MQ := 5;

     // For better compression uncomment the line below
     // NVcomp.CreateObjectStreams := true;

     retVal := NVcomp.CompressPDF('c:\in.pdf', 'c:\out.pdf');
     if retVal <> 0 then
       Application.MessageBox(PChar('Error code=' + IntToStr(retVal)),'',0)
     else
       Application.MessageBox('Done','',0);
   end;