Uses iexHelperFunctions
procedure TForm1.Button1Click(Sender: TObject);
{ Add a layer, load a bitmap into the added layer, position the layer to the center of bitmap, then merge the layer }
var
  iLayer: Integer;
  iWidth: Integer;
  iHeight: Integer;
  iRGB: TRGB;
begin
  if IEWin7FileOpenDialog1.Execute then
  begin
    iWidth := ImageEnView1.IEBitmap.Width;
    iHeight := ImageEnView1.IEBitmap.Height;
    iLayer := ImageEnView1.LayersAdd;
    ImageEnView1.IO.LoadFromFile(IEWin7FileOpenDialog1.FileName);
    if ImageEnView1.IEBitmap.Width > iWidth then
      ImageEnView1.IEBitmap.IEConvertToThumbnail(iWidth div 2, -1, True,
        rfNone, False);
    if ImageEnView1.IEBitmap.Height > iHeight then
      ImageEnView1.IEBitmap.IEConvertToThumbnail(-1, iHeight div 2, True,
        rfNone, False);
    iRGB := ImageEnView1.IEBitmap.Pixels[0, ImageEnView1.IEBitmap.Height - 1];
    ImageEnView1.Proc.SetTransparentColors(iRGB, iRGB);
    ImageEnView1.Layers[iLayer].PosX := (ImageEnView1.Layers[0].Width div 2) -
      (ImageEnView1.IEBitmap.Width div 2);
    ImageEnView1.Layers[iLayer].PosY := (ImageEnView1.Layers[0].Height div 2) -
      (ImageEnView1.IEBitmap.Height div 2);
    ImageEnView1.Layers[iLayer].Width := ImageEnView1.IEBitmap.Width;
    ImageEnView1.Layers[iLayer].Height := ImageEnView1.IEBitmap.Height;
    ImageEnView1.LayersMergeAll();
  end;
end;