Video matte generator

DETAILED DESCRIPTION p A preferred embodiment of the present invention is a matte generator for generating a video signal representative of a matte having a uniform color, comprising input means for generating signals representing three independent variables which are sufficient to characterize a color.
A processor receives the input signals and derives three numerical values from the input signals and from calibration values provided to the processor, and a quadrature modulator receives a subcarrier signal and signals representing the three numerical values and generates an encoded video signal in response thereto.
The encoded video signal and a calibration signal are applied to a calibration circuit for comparing the encoded video signal and the calibration signal and providing an output signal representative of the relationship therebetween.
The output signal of the calibration circuit is applied to the processor and is used to generate calibration values such that the encoded video signal is brought into predetermined relationship with the calibration signal.
By adjusting the calibration values, it becomes possible to bring the burst of the matte signal into phase with the burst of another video signal.
It is also possible to eliminate the need for manual calibration of offset, gain and quadrature errors.