// 64 x 64 x 32bit
ImageEnView.IO.Params.ICO.BitCount[0] := 32;
ImageEnView.IO.Params.ICO.Sizes[0].cx := 64;
ImageEnView.IO.Params.ICO.Sizes[0].cy := 64;

// 32 x 32 x 8bit
ImageEnView.IO.Params.ICO.BitCount[1] := 8;
ImageEnView.IO.Params.ICO.Sizes[1].cx := 32;
ImageEnView.IO.Params.ICO.Sizes[1].cy := 32;

// 32 x 32 x 4bit
ImageEnView.IO.Params.ICO.BitCount[2] := 4;
ImageEnView.IO.Params.ICO.Sizes[2].cx := 32;
ImageEnView.IO.Params.ICO.Sizes[2].cy := 32;

// I don't want other images
ImageEnView.IO.Params.ICO.BitCount[3] := 0;
ImageEnView.IO.Params.ICO.Sizes[3].cx := 0;
ImageEnView.IO.Params.ICO.Sizes[3].cy := 0;

// save
ImageEnView.IO.SaveToFile('D:\output.ico');

// Reading
ImageEnView1.IO.Params.ICO_Background := CreateRGB(255, 255, 255);
ImageEnView1.IO.LoadFromFileICO('D:\myicon.ico');

// Writing example
ImageEnView1.Proc.SetTransparentColors(transparent_color, transparent_color, 0);
ImageEnView1.IO.SaveToFileICO('D:\myicon.ico');

  procedure SaveICO(const FileName: string);
  var
    i: Integer;
    Color: TRGB;
  begin
    { initialize arrays }
    FillChar(Editor.IO.Params.ICO_Sizes, SizeOf(Editor.IO.Params.ICO_Sizes), 0);
    FillChar(Editor.IO.Params.ICO_BitCount, SizeOf(Editor.IO.Params.ICO_BitCount), 0);

    { has explicit output formats? }
    if EXImage.ICO.Count > 0 then
    begin
      { get transparent color }
      Color := ImageEnProc.TColor2TRGB(clWhite);

      { iterate through all ico formats... }
      for i := 0 to EXImage.ICO.Count - 1 do
        begin
          { ...and define them! }
          if EXImage.ICO[i].Bits >= 24 then
            Editor. IO.Params.ICO_Background := Color;
          Editor.IO.Params.ICO_Sizes[i].cx := EXImage.ICO[i].Width;
          Editor.IO.Params.ICO_Sizes[i].cy := EXImage.ICO[i].Height;
          Editor.IO.Params.ICO_BitCount[i] := EXImage.ICO[i].Bits;
        end;
    end;

    { save as (multiple) ico }
    Editor.IO.SaveToFileICO(FileName);