Resize JPG Image

Hi all!
I need to resize a serie of large JPG images (4000x2000) and I need a *fast* algo that will do the job...

Currently I am using a procedure based on "StrechDraw", but it's not fast enough:

//////////////////////// code /////////////////////////

procedure ResizeJPG(InFile, OutFile: string; Percent, Quality: integer);
var
  oJPG: TJPEGImage;
  oBmp: TBitmap;
begin
  try
    oJPG:=TJPEGImage.Create;
    oJPG.LoadFromFile(InFile);
  except
    MessageBox(0,PChar('Cannot open '+ExtractFileName(InFile)+'!'),
               'Error',MB_OK+MB_ICONERROR);
    Exit;
  end;

  oBmp:=TBitmap.Create;
  oBmp.Width:=Round(oJPG.Width*Percent/100);
  oBmp.Height:=Round(oJPG.Height*Percent/100);
  oBmp.Canvas.StretchDraw(Rect(0,0,oBmp.Width-1,oBmp.Height-1),oJPG);

  oJPG.Assign(oBmp);
  oJPG.CompressionQuality:=Quality;
  oJPG.Compress;
  oJPG.SaveToFile(OutFile);

  oBmp.Free;
  oJPG.Free;
end;

///////////////////////// end code /////////////////////////

I will raise the points if I get a good solution!
Thanks in advance!

  :: Cosmin