ImageEnView1.IEBitmap.Allocate(ImageEnMView1.Width, ImageEnView1.Height);
  ImageEnMView1.PaintTo( ImageEnView1.Bitmap );
  ImageEnView1.Update();

var
  i: integer;
  row, col: integer;
  imageWidth, imageHeight: integer;
  thumbWidth, thumbHeight: integer;
  rowCount, colCount: integer;
  bmp: TIEBitmap;
begin
   // you may want to change these
  imageWidth  := 1000;
  imageHeight := 1000;
  thumbWidth  := ImageEnMView1.ThumbWidth;
  thumbHeight := ImageEnMView1.ThumbHeight;

  colCount := imageWidth div thumbWidth;
  rowCount := ImageHeight div thumbHeight;
  ImageEnView1.IEBitmap.Allocate(imageWidth, imageHeight);

  row := 0;
  col := 0;

  for i:=0 to ImageEnMView1.ImageCount-1 do
  begin
    bmp := ImageEnMView1.GetTIEBitmap(i);
    bmp.RenderToTIEBitmapEx(ImageEnView1.IEBitmap,
                            col * thumbWidth, row * thumbHeight,
                            thumbWidth, thumbHeight,
                            0, 0, bmp.Width, bmp.Height,
                            255, rfFastLinear, ielNormal);
    ImageEnMView1.ReleaseBitmap(i);
    inc(col);
    if col = colCount then
    begin
      col := 0;
      inc(row);
      if row = rowCount then
        break;
    end;
  end;
  ImageEnView1.Update();
end;