A decoder for descrambling encoded satellite transmissions comprises an internal security module and a resplaceable security module. The program signal is scrambled with a key and then the key itself is...
A recording apparatus for recording a digital data, which includes an orthogonal transform unit for transforming the time axis of the digital data to the frequency axis on a block-by-block basis, a conversion...
A method and device are disclosed for scrambling-unscrambling digital image data. The data is subjected to processing for extracting the colorimetric components of the pixels forming the image, the components...
A vector quantization me employs mirrored input vectors to increase the reproduction quality of transmitted vector quantized data. A codevector is selected from a vector quantization codebook for each...
A method of encrypting a video signal employing a pseudorandom Space Filling Curve having a highly irregular scanning pattern for scanning the pixel addresses of a video picture stored in a frame buffer....
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...
An in-line data compression system which reduces the number of binary bits required to transmit a given text or similar message over a data network such as Telex or TWX. The compression unit can transmit...
