// Don't use Windows Bitmaps
  ImageEnView1.LegacyBitmap := false;

  // Load images in native format
  ImageEnView1.IO.NativePixelFormat := true;

  with ImageEnView1.IO do
    LoadFromFileBMP( ExecuteOpenDialog());

  // if the bitmap is not 8 bit paletted then convert it
  if ImageEnView1.IEBitmap.PixelFormat <> ie8p then
    ImageEnView1.IEBitmap.PixelFormat := ie8p;

procedure TMainForm.Button1Click(Sender: TObject);
  var
   intHeight, intWidth: Integer;
begin

    intHeight:= ImageEnView1.IO.Bitmap.Height ;
    intWidth:= ImageEnView1.IO.Bitmap.WidtH;



    if ((intWidth mod 2) <> 0) then
    begin
      ImageEnView1.Proc.Resample(intWidth + 1, intHeight);
      Inc(intWidth);
    end;

    if ((intHeight mod 2) <> 0) then
    begin
      ImageEnView1.Proc.Resample(intWidth, intHeight + 1);
      Inc(intHeight) ;
    end;

    intWidth:= intWidth div 2;
    intHeight:= intHeight div 2;

    ImageEnView1.Proc.ImageResize(intWidth, intHeight, iehLeft, ievBottom);
    ImageEnView1.Proc.ConvertTo(ImageEnView1.Proc.CalcImageNumColors);
    ImageEnView1.IO.Params.BitsPerSample := 8;
    ImageEnView1.IO.Params.SamplesPerPixel := 1;
    ImageEnView1.IO.SaveToFileBMP('d:\Half.bmp');

end;