Abstract: A video signal is encrypted by pseudo-random variation of portions of lines thereof to be horizontally scanned that are devoid of video information. Thus, the durations of line blanking intervals may be varied. The variation is done in accordance with an encryption keys which is employed at the receiver to decrypt the encrypted video signal.

Abstract: A method and apparatus for creating a television signal and encrypting or decrypting the signal at the same time. Luminance and chrominance information are received by the apparatus and stored in separate television scan line stores. The stored liminance and chrominance information is read out from their respective stores at a frequency corresponding to a desired format or standard to create the television signal. The signal may be simultaneously encrypted or decrypted by delaying the time at which the luminance and/or chrominance information is read out in accordance with an encryption or decryption key.

Abstract: Noise in a video picture is sharply reduced using the redundancy of information present in those portions of the picture which remain unchanged through several successive frames. A number of successive frames are compared to determine which portions of the picture are in motion and which are stationary. The moving portions of the image are separated from the stationary portions and are processed in a conventional manner. The stationary portions, however, are combined on a frame-by-frame basis to produce a highly noise-free averaged signal. In color systems, the conventional luminance-chroma separation methods used for the moving portions of the picture are replaced, in the stationary portions, by an opposite-phase frame comparison method which provides 100% separation regardless of the nature of the image.