....

var
  OpenDialog: TOpenDialog;
  SelectedFiles: TStrings;
begin
  OpenDialog := TOpenDialog.Create(nil);
  try
    OpenDialog.Options := [TOpenOption.ofAllowMultiSelect];
    // Customize the filter as needed
    OpenDialog.Filter := 'All Files|*.*';
    if OpenDialog.Execute then
    begin
      SelectedFiles := OpenDialog.Files;
      // Process the selected files (e.g., display their names)
      ShowMessage('Selected files: ' + SelectedFiles.Text);

      lst_ImageList.clear;
      lst_ImageList.items.AddStrings(SelectedFiles) ;

      EvaluateSelectedFiles ( TStringList( SelectedFiles ) );

    end;
  finally
    OpenDialog.Free;
  end;
end;

procedure TForm.EvaluateSelectedFiles(SelectedFiles : TStringList);