Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
349 words
A method for generating a keyed, true-transparency image information signal combine V C , the method comprising the steps of: receiving a plurality of image information signals, each of said image information signals being received from a respective one of a corresponding plurality of channels, receiving a plurality of input key signals, each of said input key signals corresponding to a respective one of said image information signals, ranking the channels in a defined order to obtain a prioritized order among the channels, responsive to a respective one of said input key signals, generating a respective key-requested signal, receiving a key-available signal, responsive to the input key signals, generating a respective key-taken signal and a respective key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by multiplying the key-requested signal and the key-available signal, and (b) such that the key-now-available signal is generated by algebraically subtracting the key-taken signal from the key-available signal, responsive to the key-taken signal, producing a respective processed key signal Pk i for an i-th respective one of said channels: (c) such that the produced processed key signal Pk i for the i-th channel is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for an i-th respective one of said image information signals is produced so that: ##EQU19## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals, responsive to the respective produced processed key signal, cutting the respective image information signal, and combining a plurality of cut image information signals to generate said keyed, true-transparency image information combine.
Claim 2
Independent Claim
349 words
A method for generating a keyed, true-transparency image information signal combine V C , the method comprising the steps of: receiving a plurality of image information signals, each of said image information signals being received from a respective one of a corresponding plurality of channels, receiving a plurality of input key signals, each of said input key signals corresponding to a respective one of said image information signals, ranking the channels in a defined order to obtain a prioritized order among the channels, responsive to a respective one of said input key signals, generating a respective key-requested signal, receiving a key-available signal, responsive to the input key signals, generating a respective key-taken signal and a respective key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by multiplying the key-requested signal and the key-available signal, and (b) such that the key-now-available signal is generated by algebraically subtracting the key-taken signal from the key-available signal, responsive to the key-taken signal, producing a respective processed key signal Pk i for an i-th respective one of said channels: (c) such that the produced processed key signal Pk i for the i-th channel is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for an i-th respective one of said image information signals is produced so that: ##EQU19## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals, responsive to the respective produced processed key signal, cutting the respective image information signal, and combining a plurality of cut image information signals to generate said keyed, true-transparency image information combine.
Claim 3
Dependent Claim
64 words
The method defined in claim 1 wherein the step of combining the plurality of cut image information signals to generate a combine further comprises the step of: responsive to a plurality of N produced processed key signals Pk i and responsive to a plurality of N image information signals V i , generating said keyed, true-transparency image information combine V C so that: ##EQU20##
Claim 4
Dependent Claim
38 words
The method defined in claim 1 further comprising the step of: extending the generated key-now-available signal from a higher priority i-th channel to a lower priority (i+1)-st channel as the key-available signal for the lower priority (i+1)-st channel.
Claim 5
Independent Claim
349 words
A method for generating a keyed, true-transparency image information signal combine V C , the method comprising the steps of: receiving a plurality of image information signals, each of said image information signals being received from a respective one of a corresponding plurality of channels, receiving a plurality of input key signals, each of said input key signals corresponding to a respective one of said image information signals, ranking the channels in a defined order to obtain a prioritized order among the channels, responsive to a respective one of said input key signals, generating a respective key-requested signal, responsive to the input key signals, generating a respective key-taken signal and a respective key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by algebraically subtracting the key-now-available signal from a key-available signal, and (b) such that the key-now-available signal is generated by multiplying the key-available signal and another key signal, which another key signal is equal to one minus the key-requested signal, responsive to the key-taken signal, producing a respective processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU21## where B 0 =0 and where Bk i is the input key signal corresponding to i-th respective one of said image information signals, responsive to the respective produced processed key signal, cutting the respective image information signal, and combining a plurality of cut image information signals to generate said keyed, true-transparency image information combine V C .
Claim 6
Independent Claim
349 words
A method for generating a keyed, true-transparency image information signal combine V C , the method comprising the steps of: receiving a plurality of image information signals, each of said image information signals being received from a respective one of a corresponding plurality of channels, receiving a plurality of input key signals, each of said input key signals corresponding to a respective one of said image information signals, ranking the channels in a defined order to obtain a prioritized order among the channels, responsive to a respective one of said input key signals, generating a respective key-requested signal, responsive to the input key signals, generating a respective key-taken signal and a respective key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by algebraically subtracting the key-now-available signal from a key-available signal, and (b) such that the key-now-available signal is generated by multiplying the key-available signal and another key signal, which another key signal is equal to one minus the key-requested signal, responsive to the key-taken signal, producing a respective processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU21## where B 0 =0 and where Bk i is the input key signal corresponding to i-th respective one of said image information signals, responsive to the respective produced processed key signal, cutting the respective image information signal, and combining a plurality of cut image information signals to generate said keyed, true-transparency image information combine V C .
Claim 7
Dependent Claim
70 words
The method defined in claim 4 wherein the step of combining the plurality to cut image information signals to generate said keyed, true-transparency image information combine V C further comprises the step of: responsive to a plurality of N produced processed key signals Pk i and responsive to a plurality of N image information signals V i , generating said keyed, true-transparency image information combine V C so that: ##EQU22##
Claim 8
Dependent Claim
38 words
The method defined in claim 4 further comprising the step of: extending the generated key-now-available signal from a higher priority i-th channel to a lower priority (i+1)-st channel as the key-available signal for the lower priority (i+1)-st channel.
Claim 9
Independent Claim
386 words
A system for generating a keyed, true-transparency image information signal combine V C , the system including: means for receiving a plurality of image information signals, each of said image information signals being received from a respective one of a corresponding plurality of channels, means for receiving a plurality of input key signals, each of said input key signals corresponding to a respective one of said image information signals, means for ranking the channels in a defined order to obtain a prioritized order among the channels, means, responsive to the input key signals, for producing a respective processed key signal for a respective one of said image information signals, means, responsive to the respective produced processed key signal, for cutting the respective image information signal, and means for combining a plurality of cut image information signals to generate said keyed, true-transparency image information signal combine wherein the improvement comprises means, responsive to a respective one of said input key signals, for generating a respective key-requested signal and means for receiving a key-available signal from a higher priority channel, means, responsive to the input key signals, for generating a respective key-taken signal and a respective key-now-available signal for a respective image information signal: (a) such that the key-taken signal is generated by multiplying the key-requested signal and the key-available signal, and (b) such that the key-now-available signal is generated by algebraically subtracting the key-taken signal from the key-available signal, and means, responsive to the key-taken signal, for generating the produced processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU23## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.
Claim 10
Independent Claim
386 words
A system for generating a keyed, true-transparency image information signal combine V C , the system including: means for receiving a plurality of image information signals, each of said image information signals being received from a respective one of a corresponding plurality of channels, means for receiving a plurality of input key signals, each of said input key signals corresponding to a respective one of said image information signals, means for ranking the channels in a defined order to obtain a prioritized order among the channels, means, responsive to the input key signals, for producing a respective processed key signal for a respective one of said image information signals, means, responsive to the respective produced processed key signal, for cutting the respective image information signal, and means for combining a plurality of cut image information signals to generate said keyed, true-transparency image information signal combine wherein the improvement comprises means, responsive to a respective one of said input key signals, for generating a respective key-requested signal and means for receiving a key-available signal from a higher priority channel, means, responsive to the input key signals, for generating a respective key-taken signal and a respective key-now-available signal for a respective image information signal: (a) such that the key-taken signal is generated by multiplying the key-requested signal and the key-available signal, and (b) such that the key-now-available signal is generated by algebraically subtracting the key-taken signal from the key-available signal, and means, responsive to the key-taken signal, for generating the produced processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU23## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.
Claim 11
Dependent Claim
49 words
The system defined in claim 7 wherein the combining means further comprises: responsive to a plurality of N produced processed key signals Pk i and responsive to a plurality of N image information signals V i , generating said keyed, true-transparency image information combine V C so that: ##EQU24##
Claim 12
Dependent Claim
37 words
The system defined in claim 7 further comprising: means for extending the generated key-now-available signal from a higher priority i-th channel to a lower priority (i+1)-st channel as the key-available signal for the lower priority (i+1)-st channel.
Claim 13
Independent Claim
395 words
A system for generating a keyed, truetrasparency image information signal combine V C , the system including: means for receiving a plurality of image information signals, each of said image information signals being received from a respective one of a corresponding plurality of channels, means for receiving a plurality of input key signals, each of said input key signals corresponding to a respective one of said image information signals, means for ranking the channels in a defined order to obtain a prioritized order of the channels, means, responsive to the input key signals, for generating a respective processed key signal for a respective one of said image information signals, means, responsive to the respective produced processed key signal, for cutting the respective image information signal, and means for combining a plurality of cut image information signals to generate said keyed, true-transparency image information signal combine wherein the improvement comprises means, responsive to a respective one of said input key signals, for generating a respective key-requested signal and means for receiving a key-available signal from a higher priority channel, means, responsive to the input key signals, for generating a respective key-taken signal and a respective key-now-available signal for a respective image information signal: (a) such that the key-taken signal is generated by algebrically subtracting the key-now-available signal from the key-available signal, and (b) such that the key-now-available signal is generated by multiplying the key-available signal and another key signal, which another key signal is equal to one minus the key-requested signal, responsive to the key-taken signal, generating the produced processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk j for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU25## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.
Claim 14
Independent Claim
395 words
A system for generating a keyed, truetrasparency image information signal combine V C , the system including: means for receiving a plurality of image information signals, each of said image information signals being received from a respective one of a corresponding plurality of channels, means for receiving a plurality of input key signals, each of said input key signals corresponding to a respective one of said image information signals, means for ranking the channels in a defined order to obtain a prioritized order of the channels, means, responsive to the input key signals, for generating a respective processed key signal for a respective one of said image information signals, means, responsive to the respective produced processed key signal, for cutting the respective image information signal, and means for combining a plurality of cut image information signals to generate said keyed, true-transparency image information signal combine wherein the improvement comprises means, responsive to a respective one of said input key signals, for generating a respective key-requested signal and means for receiving a key-available signal from a higher priority channel, means, responsive to the input key signals, for generating a respective key-taken signal and a respective key-now-available signal for a respective image information signal: (a) such that the key-taken signal is generated by algebrically subtracting the key-now-available signal from the key-available signal, and (b) such that the key-now-available signal is generated by multiplying the key-available signal and another key signal, which another key signal is equal to one minus the key-requested signal, responsive to the key-taken signal, generating the produced processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk j for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU25## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.
Claim 15
Dependent Claim
49 words
The system defined in claim 10 wherein the combining means further comprises: responsive to a plurality of N produced processed key signals Pk i and responsive to a plurality of N image information signals V i , generating said keyed, true-transparency image information combine V C so that: ##EQU26##
Claim 16
Dependent Claim
37 words
The system defined in claim 10 further comprising: means for extending the generated key-now-available signal from a higher priority i-th channel to a lower priority (i+1)-st channel as the key-available signal for the lower priority (i+1)-st channel.
Claim 17
Dependent Claim
307 words
Keyer means for generating a processed key signal usable for generating a keyed, true-transparency image information signal combine V C , the keyer means comprising: means for receiving a plurality of input key signals, each of said input key signals being received from a respective one of a corresponding plurality of prioritized channels and each of said input key signals corresponding to a respective one of a plurality of image information signals, means, responsive to a respective input key signal, for generating a respective key-requested signal, means for receiving a key-available signal from a higher priority channel, means, responsive to the input key signals, for generating a respective key-taken signal and a respective-key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by multiplying the key-requested signal and the key-available signal, and (b) such that the key-now-available signal is generated by algebraically subtracting the key-taken signal from the key-available signal, and means, responsive to the key-taken signal, for generating a produced processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU27## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.
Claim 18
Dependent Claim
307 words
Keyer means for generating a processed key signal usable for generating a keyed, true-transparency image information signal combine V C , the keyer means comprising: means for receiving a plurality of input key signals, each of said input key signals being received from a respective one of a corresponding plurality of prioritized channels and each of said input key signals corresponding to a respective one of a plurality of image information signals, means, responsive to a respective input key signal, for generating a respective key-requested signal, means for receiving a key-available signal from a higher priority channel, means, responsive to the input key signals, for generating a respective key-taken signal and a respective-key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by multiplying the key-requested signal and the key-available signal, and (b) such that the key-now-available signal is generated by algebraically subtracting the key-taken signal from the key-available signal, and means, responsive to the key-taken signal, for generating a produced processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU27## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.
Claim 19
Dependent Claim
318 words
Keyer means for generating a processed key signal usable for generating a keyed, true-transparency image information signal combine V C , the keyer means comprising: means for receiving a plurality of input key signals, each of said input key signals being received from a respective one of a corresponding plurality of prioritized channels and each of said input key signals corresponding to a respective one of a plurality of image information signals, means, responsive to a respective input key signal, for generating a respective key-requested signal, means for receiving a key-available signal from a higher priority channel, means, responsive to the input key signals, for generating a respective key-taken signal and a respective key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by algebraically subtracting the key-now-available signal from the key-available signal, and (b) such that the key-now-available signal is generated by multiplying the key-available signal and another key signal, which another key signal is equal to one minus the key-requested signal, and responsive to the key-taken signal, generating a produced processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU28## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.
Claim 20
Dependent Claim
318 words
Keyer means for generating a processed key signal usable for generating a keyed, true-transparency image information signal combine V C , the keyer means comprising: means for receiving a plurality of input key signals, each of said input key signals being received from a respective one of a corresponding plurality of prioritized channels and each of said input key signals corresponding to a respective one of a plurality of image information signals, means, responsive to a respective input key signal, for generating a respective key-requested signal, means for receiving a key-available signal from a higher priority channel, means, responsive to the input key signals, for generating a respective key-taken signal and a respective key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by algebraically subtracting the key-now-available signal from the key-available signal, and (b) such that the key-now-available signal is generated by multiplying the key-available signal and another key signal, which another key signal is equal to one minus the key-requested signal, and responsive to the key-taken signal, generating a produced processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU28## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.
Claim 21
Independent Claim
300 words
A method for generating a processed key signal usable for generating a keyed, true-transparency image information signal combine V C , the method comprising the steps of: receiving a plurality of input key signals, each of said input key signals being received from a respective one of a corresponding plurality of prioritized channels and each of said input key signals corresponding to a respective one of a plurality of image information signals, responsive to a respective input key signal, generating a respective key-requested signal and receiving a key-available signal from a higher priority channel, responsive to the input key signals, generating a respective key-taken signal and a respective key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by multiplying the key-requested signal and the key-available signal, and (b) such that the key-now-available signal is generated by algebraically subtracting the key-taken signal from the key-available signal, and responsive to the key-taken signal, generating a produced processed key signal: (c) such that the produced processed key signal Pk i an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU29## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.
Claim 22
Independent Claim
300 words
A method for generating a processed key signal usable for generating a keyed, true-transparency image information signal combine V C , the method comprising the steps of: receiving a plurality of input key signals, each of said input key signals being received from a respective one of a corresponding plurality of prioritized channels and each of said input key signals corresponding to a respective one of a plurality of image information signals, responsive to a respective input key signal, generating a respective key-requested signal and receiving a key-available signal from a higher priority channel, responsive to the input key signals, generating a respective key-taken signal and a respective key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by multiplying the key-requested signal and the key-available signal, and (b) such that the key-now-available signal is generated by algebraically subtracting the key-taken signal from the key-available signal, and responsive to the key-taken signal, generating a produced processed key signal: (c) such that the produced processed key signal Pk i an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU29## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.
Claim 23
Independent Claim
312 words
A method for generating a processed key signal usable for generating a keyed, true-transparency image information signal combine V C , the method comprising the steps of: receiving a plurality of input key signals, each of said input key signals being received from a respective one of a corresponding plurality of prioritized channels and each of said input key signals corresponding to a respective one of a plurality of image information signals, responsive to a respective input key signal, generating a respective key-requested signal, receiving a key-available signal from a higher priority channel, responsive to the input key signals, generating a respective key-taken signal and a respective key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by algebraically subtracting the key-now-available signal from the key-available signal, and (b) such that the key-now-available signal is generated by multiplying the key-available signal and another key signal, which another key signal is equal to one minus the key-requested signal, and responsive to the key-taken signal, generating a produced processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU30## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.
Claim 24
Independent Claim
312 words
A method for generating a processed key signal usable for generating a keyed, true-transparency image information signal combine V C , the method comprising the steps of: receiving a plurality of input key signals, each of said input key signals being received from a respective one of a corresponding plurality of prioritized channels and each of said input key signals corresponding to a respective one of a plurality of image information signals, responsive to a respective input key signal, generating a respective key-requested signal, receiving a key-available signal from a higher priority channel, responsive to the input key signals, generating a respective key-taken signal and a respective key-now-available signal for a respective one of said image information signals: (a) such that the key-taken signal is generated by algebraically subtracting the key-now-available signal from the key-available signal, and (b) such that the key-now-available signal is generated by multiplying the key-available signal and another key signal, which another key signal is equal to one minus the key-requested signal, and responsive to the key-taken signal, generating a produced processed key signal: (c) such that the produced processed key signal Pk i for an i-th respective one of said channels is dependent upon the input key signals Bk j for one or more channels, which have a priority that is not lower than the priority of the i-th channel, and (d) such that the produced processed key signal Pk i for the i-th channel is not dependent upon a produced processed key signal Pk j for a j-th respective one of said channels where i and j are not equal, and (e) such that the produced processed key signal Pk i for the i-th image information signal is produced so that: ##EQU30## where B 0 =0 and where Bk i is the input key signal corresponding to the i-th respective one of said image information signals.