| 6870931 |
Method and system for embedding message data in a digital image sequence |
| Mar-22-2005 |
A method for embedding message data in a digital image sequence having two or more frames, includes the steps of: providing a dispersed message image representative of the message data; and adding spatially... |
| 6519340 |
Method and apparatus for encryption using partial information |
| Feb-11-2003 |
A method and apparatus of encrypting optical images using binarization or phase only information is presented with a number of ways to secure the image also being provided. An image to be encrypted is... |
| 6175630 |
Method and apparatus for level and phase control of a plurality of RF signals |
| Jan-16-2001 |
A multichannel television access control system is disclosed wherein processing of the broadband signal is performed by gated coherent RF injection on a plurality of channels, thereby effecting selective... |
| 6148320 |
Multichannel digital signal generation method and apparatus |
| Nov-14-2000 |
A multichannel television access control system is disclosed wherein processing of the broadband signal is performed by gated coherent RF injection on a plurality of channels, thereby effecting selective... |
| 5864621 |
Broadband television scrambling and descrambling system |
| Jan-26-1999 |
A multichannel television access control system is disclosed wherein processing of the broadband signal is performed by gated coherent RF injection on a plurality of channels, thereby effecting selective... |
| 5754650 |
Simultaneous multichannel television access control system and method |
| May-19-1998 |
A multichannel television access control system is disclosed wherein processing of the broadband signal is performed by gated coherent RF injection on a plurality of channels, thereby effecting selective... |
| 5430799 |
Multichannel television signal scrambling and descrambling system and method |
| Jul-4-1995 |
A multichannel television access control system is disclosed wherein processing of the broadband signal is performed by gated coherent RF injection on a plurality of channels, thereby effecting selective... |
| 4802213 |
Sound masking in phase reversal TV scrambling system |
| Jan-31-1989 |
A TV scrambling system includes means for scrambling a TV signal by phase reversing the carrier at a horizontal rate. A sound masking circuit includes a phase locked loop which operates at five times the... |
| 4790010 |
Enhanced scrambling method and system for TV signals |
| Dec-6-1988 |
A television signal transmission system includes a cable head-end having a scrambler for scrambling a television signal and a subscriber decoder having an unscrambler for unscrambling the television signal... |
| 4706284 |
Television signal data transmission system |
| Nov-10-1987 |
A television signal data transmission system comprises means for transmitting a television signal in which the phase of the RF carrier is modified during a periodically recurring interval by a SAW filter... |
| 4706283 |
Television signal scrambling system |
| Nov-10-1987 |
A television signal transmission system comprises a headend including a pair of SAW filters having equal delays, one filter having amplitude and normalized phase versus frequency response characteristics... |
| 4598313 |
Television signal scrambling system |
| Jul-1-1986 |
An encoded television signal is transmitted in the form of an inverted video component amplitude modulating an RF carrier to a selected percentage of modulation and characterized by inverted reference... |
| 4467353 |
Television signal scrambling system and method |
| Aug-21-1984 |
A system for encoding or scrambling a television signal and for subsequently decoding or unscrambling the signal for presentation on the viewing screen of a television receiver. Encoding is achieved by... |
| 4253114 |
High security subscription television system employing real time control of subscriber's program reception |
| Feb-24-1981 |
A high security subscription television system which includes the feature of dynamic scrambling and descrambling of cable-connected television signals in response to real-time coded control signals. The... |
| 4034402 |
Video scrambling system |
| Jul-5-1977 |
A system for scrambling and descrambling the video portion of a television signal. At the transmitting end, the video is scrambled by shifting the phase angle of the carrier relative to that of the sidebands... |
| 4002825 |
System for encoding and decoding amplitude modulated signals |
| Jan-11-1977 |
A system for encoding or scrambling an amplitude modulated signal, such as the video component of a standard television signal, and for subsequently decoding or unscrambling the signal so as to restore... |
| 3999005 |
Secure transmission of AM or FM signals |
| Dec-21-1976 |
A method and system for scrambling amplitude-modulated or frequency-modulated signals at a transmitter and descrambling the scrambled signals at a receiver. The scrambling is effected at the transmitter... |
| 3996418 |
Scrambler and decoder for secure television system |
| Dec-7-1976 |
A scrambler for a television system alternately inverts the phase of the carrier which is modulated by the television signal. A binary coding signal controls the manner of the carrier-phase inversion.... |
| 3982062 |
Video encription system |
| Sep-21-1976 |
Encription apparatus for restricting distribution of private (e.g., premium) video programs propagated by a CATV cable network, radiation or the like employs picture carrier isolating, phase shifting and... |
| 3936593 |
Scrambler and decoder for a television signal |
| Feb-3-1976 |
An improved scrambler and decoder for a television signal is described wherein a television carrier is inverted in phase and subjected to low frequency amplitude modulation to obtain enhanced channel security.... |
