procedure createPDF();
var
  DC : Variant;
  RVal : Integer;
  docToConvert : String;
begin
  docToConvert := 'd:\test.tif';

  try
    DC := CreateOleObject('Neevia.docCreator');
    RVal := DC.ConvertImage(docToConvert, docToConvert + '.pdf');

    If (RVal <> 0) Then
      ShowMessage('Error while converting image!!! Code: '+IntToStr(RVal))
    else
      ShowMessage('Done converting !!!');
  finally
    DC := Unassigned;
  end;
end;