Process and circuit layout for the recognition of an identification sign (signum) contained in a video signal
AssigneeDeutsche Thomson-Brandt GmbH
InventorsJean-Claude Guillon, Patrick Daniel
Life of this patent
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Abstract
Circuitry for recognizing an authorization code included in a video signal for enabling a subscriber's television receiver, includes quantizing apparatus for coarsely quantizing the received signal. A correlator designed to recognize the authorization code is coupled the quantizer and produces an array of correlation values. The correlation values are coupled to a threshold circuit which converts the correlation values to bistate values. Further circuitry evaluates the distribution of bistate values to determine reception of the authorization code.
Claims18
A method for the recognition of an identification signum contained in a television video signal, comprising:
- providing a reference signal corresponding to said identification signum;
- providing a reference value;
- correlating a portion of said video signal containing said identification signum with said reference signal to produce a sequence of correlation values;
- comparing the sequence of correlation values against said reference value and indicating the occurrence of said identification signum on the occurrence of a predetermined distribution of comparison values.
Apparatus for detecting the presence of an identification sign contained in a television video signal, said apparatus comprising:
- a terminal for receiving said video signal;
- means for providing reference signal corresponding to said identification signum;
- a correlator, coupled to said terminal and said means for providing reference signal, for correlating at least a portion of said video signal with said reference signal to produce correlation values;
- means for providing a reference value;
- and
- means, including comparing means, responsive to said correlation values and said reference value to produce a signal indicative of the occurrence of said identification signum.
Apparatus for detecting an identification signum included in an active portion of a television video signal, said apparatus comprising:
- a signal input terminal for receiving said video signal;
- means for providing a reference signal representing said identification signum;
- a correlator coupled to said input terminal and responsive to said reference signal for generating an array of values representing the relative correlation between said video signal and said reference signal;
- means responsive to said array of values for producing a further array of values representing said array of values, values in said further array having a first state if the corresponding value in said array is greater than a predetermined value and a second state otherwise;
- and
- means responsive to said further array of values for detecting a predetermined distribution of said first and second states of values of said further array, to generate a signal indicating the occurrence of said identification signum.
A method for generating a control signal indicating recognition of an identification signum contained in a portion of a television video signal comprising:
- correlating said video signal with a reference representing said identification signum to produce a first array of correlation values;
- comparing the correlation values of said array with a predetermined value to generate a second array of values, respective values in said second array having first or second states for the corresponding values in said first array being respectively greater or lesser than said predetermined value;
- and
- generating said control signal if the values in said second array satisfy a predetermined distribution of first and second states.
Dependencies are inferred from the claim text.