An AD-converted digital video data is encoded by a difference encoding method before it is outputted and such encoded digital video data is then outputted, after it is converted to gray code or to a predetermined code in which a fixed value is added. An enclosed region is formed in the first portion for receiving a cleaning agent or disinfectant. Furthermore, the dispersion can have a shelf-life of at least about 1 hour or more at 25 C. If the system is multi-layered, some code images are also sent to the intermediate-level network management computers. And the apparatus may be caused to interpolate a value of the selected display pixel from at least some of the identified point samples using the generated encoding. The frame can be inverted as required to allow the molded sections to be positioned above or below the rolled sections.