[[seoane]]

Aunque puede que esta otra forma de hacerlo te resulte mejor:

Código Delphi [-]
procedure Capturar(Filename: string; Panel: TPanel);
var
  FormImage: TBitmap;
  Bitmap: TBitmap;
  Jpg: TJPEGImage;
begin
  if Panel.Owner is TForm then
  begin
    FormImage := TForm(Panel.Owner).GetFormImage;
    Bitmap:= TBitmap.Create;
    Jpg:= TJPEGImage.Create;
    try
      Bitmap.Width:= Panel.Width;
      Bitmap.Height:= Panel.Height;
      BitBlt(Bitmap.Canvas.Handle,0,0,Bitmap.Width,Bitmap.Height,
        FormImage.Canvas.Handle,Panel.Left,Panel.Top,SRCCOPY);
      Jpg.CompressionQuality:= 60;
      Jpg.Assign(Bitmap);
      Jpg.SaveToFile(Filename);
    finally
      FormImage.Free;
      Bitmap.Free;
      Jpg.Free;
    end;
  end;
end;