An improved tunnel or covered highway structure with means for easy and quick access to the interior. The intermediate product may be wool-like with wavy and randomly oriented fibers formed by from the fragmented filaments. In a method aspect of the present invention, an erectile dysfunction drug is delivered to a patient through an inhalation route. A magnitude of a discontinuous component in a frequency domain belonging to the block boundary is adjusted based on a magnitude of a corresponding discontinuous component selected from a pixel contained entirely within a block adjacent the block boundary.