Abstract: A method and apparatus is disclosed for combining a first video signal representative of a first image and a second video signal representative of a second image. In one embodiment, the first video signal is filtered to remove high frequency two-dimensional diagonal frequency components therefrom. The second video signal is also filtered to remove high frequency two-dimensional diagonal frequency components therefrom. The filtered second video signal is two-dimensionally modulated, and the filtered first video signal is combined with said modulated filtered second video signal. In a further embodiment, filtered signals are spatially decimated and combined.

Abstract: A method and an apparatus are disclosed for encoding and decoding video to achieve bandwidth compression. In one embodiment, frames of a video signal are divided into a multiplicity of tiles. The picture content of each tile is separated into a plurality of frequency bands having a predetermined priority order. Motion is determined at each tile from changes in picture content of the tile from frame to frame. Signals are generated for each frame, the signals including an indication of the motion status for each tile and a representation of a frequency band for each tile. The frequency band representation for each particular tile is selected as a function of the motion status for the particular tile.

Abstract: A passive, non-intrusive pay telephone monitoring system is disclosed for maintaining a talley of the amount of money present in a money box. A signal is sent over the line, interconnecting the pay telephone with its central office equipment when money in the box is collected by a collection agent, and the collected amount of money and the time of collection are then stored for verification of the collected amount.