Method of generating chromaticity point-dependent switching information from coded color video signals

Claim 3

A method as claimed in claim 1 wherein the coded color video signals are coded according to the PAL standard, said method further comprising commutating the phase of the phase-adjustable color carrier wave in a correct manner for PAL so that a color vector corresponding to a chromaticity point adjusted at a given instant is recognized in every line of the color video signal.

Claim 4

A method as claimed in claim 1, further comprising independently selecting the adjustment for chromaticity point, color selectivity, and color saturation at which the switching information is generated.

Claim 5

A method as claimed in claim 1 further comprising adding the phase-adjustable color carrier wave in the threshold circuit to the chrominance signal component and to the adjusted threshold value of the threshold circuit, respectively.

Claim 6

A method as claimed in claim 4, further comprising adding a phase-adjustable color carrier wave having adjustable amplitude and a phase position shifter 180° with respect to the desired phase position to the chrominance signal component of the coded color video signal, and deriving the switching information by decreasing the color carrier wave oscillation to zero amplitude.

Claim 7

A circuit for generating chromaticity point-dependent switching information from coded color video signals, said circuit comprising a color carrier wave oscillator synchronized by color synchronization signals derived from the coded color video signals, a filter means for filtering the chrominance signal component present as a modulated color carrier wave from the coded color video signal, a phase-adjusting stage means coupled to said oscillator for supplying a phase-adjustable color carrier wave, and a threshold circuit coupled to said filter and to said phase adjusting stage and having an adjustable threshold value, said threshold circuit having at least one switching means for passing and blocking the chrominance signal component supplied to it and an output means for providing the chroma commutation signal.

Claim 8

A circuit for generating chromaticity point-dependent switching information from coded color video signals, said circuit comprising a color carrier wave oscillator synchronized by color synchronization signals derived from the coded color video signals, a filter means for filtering the chrominance signal component present as a modulated color carrier wave from the coded color video signal, a phase-adjusting stage means coupled to said oscillator for supplying a phase-adjustable color carrier wave, and a threshold circuit coupled to said filter and to said phase adjusting stage and having an adjustable threshold value, said threshold circuit having at least one switching means for passing and blocking the chrominance signal component supplied to it and an output means for providing the chroma commutation signal.

Claim 9

A circuit as claimed in claim 6 wherein the color video signals are coded according to the PAL standard, and said phase adjusting stage comprises means for commutating the phase of the phase-adjustable color carrier wave in a correct manner for PAL so that a color vector corresponding to a chromaticity point adjusted at a given instant is recognized in every line of the color video signal.

Claim 10

A circuit as claimed in claim 6, further comprising a plurality of means for adjusting chromaticity point, color selectivity and color saturation at which the switching information is generated, said chromaticity point adjusting means being coupled to the phase adjusting stage, said color selectivity and saturation adjusting means being coupled to said threshold circuit.

Claim 11

A circuit as claimed in claim 6, wherein said switching means comprises two switching stages, a first phase rotating element coupled between the phase adjusting stage and one of said switching stages, a pair of series circuits each including a trigger circuit and a flip flop circuit coupled in series with each of the switching stages respectively, and a gate coupled to the outputs of the flip flop circuits and to the output means of the threshold circuit.

Claim 12

A circuit as claimed in claim 9, wherein the switching means further comprises a third switching stage, a second phase rotating element coupled between said third switching stage and said phase adjusting stage, said third switching stage being coupled in parallel to said switching stage which is coupled to said first phase rotating element, the two phase rotating elements having a different phase rotation angle.