Thumbnails - como fazer ?

procedure CreateThumbs(Diretorio: String; ThumbSize: Word; Owner: TWinControl);
var
  i: Word;
  Img: TImage;
  Ext: String;
  Arqs: TStrings;
  wTop, wLeft: Word;
  Obj: TObject;
begin
  //-- Listar arquivos do diretorio
  Diretorio := IfThen(RightStr(Diretorio,1) <> ´\´ , Diretorio + ´\´ , Diretorio);
  Arqs := TShell.ListaArq(Diretorio);

  //-- Posição dos componentes
  wTop  := 8;
  wLeft := 8;

  //-- Destruir componentes de thumbs antigo
  if Owner.ComponentCount > 0 then
    begin
      for i := Owner.ComponentCount-1 downto 0 do
        begin
          if (Owner.Components[i] is TImage) then
            if (Owner.Components[i] as TImage).Tag = 785 then
              begin
                Obj := Owner.Components[i];
                FreeAndNil(Obj);
              end;
        end;
    end;

  //-- Exibir imagens
  if Arqs.Count > 0 then
    begin
      for i := 0  to Arqs.Count -1 do
        begin
          Ext := UpperCase(ExtractFileExt(Arqs[i]));

          if (Ext = ´.BMP´) or (Ext = ´.JPG´) or (Ext = ´.WMF´) or (Ext = ´.JPEG´) then
            begin
              Img := TImage.Create(Owner);
              Img.Parent := Owner;
              Img.Stretch := True;
              Img.Proportional := True;
              Img.Center := True;
              Img.Tag := 785;
              Img.Picture.LoadFromFile(Diretorio + Arqs[i]);
              Img.SetBounds(wLeft,wTop,ThumbSize,ThumbSize);

              //-- Pular linha qdo ultrapassar o width do scrollbox
              wLeft := ThumbSize + 8 + wLeft;
              if wLeft > Owner.Width then
                begin
                  wLeft := 8;
                  wTop := ThumbSize + 8 + wTop;
                end
            end;

        end;
    end;
end;

end.

  TShell = class
  public
    class function ListaArq(Caminho: string;Filtro : String = ´*.*´): TStrings;
  end;

implementation

{ TShell }

class function TShell.ListaArq(Caminho, Filtro: String): TStrings;
var
  SR : TSearchRec;
  I  : integer;
begin
  Result := TStringList.create;
  I := FindFirst(Caminho+Filtro, faAnyFile, SR);
  while I = 0 do
    begin
      if (SR.Attr and faDirectory) <> faDirectory then
         Result.Add(SR.Name);
      I := FindNext(SR);
    end;
end;

procedure TForm1.BitBtn1Click(Sender: TObject);
begin
  CreateThumbs(´D:\Nosredna\Meus documentos\Minhas imagens´,50,ScrollBox1);
end;