Chroma deying system utilizing remote controlled chroma keyer

Claim 2

Circuitry responsive to a color television camera or other similar source which produces at least three nonencoded color signals such as red (R), green (G), and blue (B) signals, said circuitry selecting any desired color signal from said source and comprising: matrix means responsive to said red, green, and blue signals to produce red, blue, and luminance signals; means for developing at least two control signals, which are respectively 90*out-of-phase with one another; filter means responsive to said red, blue, and luminance signals and said two control signals for producing a signal having the form (R-Y) sin theta + (B-Y) cos theta where theta is a function of said control means and corresponds to said desired color; and whereby said filter means causes the desired color signal to be maximized with respect to other color signals and thus, the filter means acts as a chromatic filter, the ''''pass band'''' of which may be positioned anywhere in the color spectra by said control means.

Claim 3

Circuitry as in claim 1 including exponential amplifier means for increasing the selectivity of said filter means by further increasing the amplitude of said desired color signal with respect to said other color signals.

Claim 4

Circuitry as in claim 1 where said control means is remotely located from said filter means.

Claim 5

Circuitry as in claim 1 where said filter means includes: at least two differential amplifiers, the first of which is responsive to said red and luminance signals to form at least the difference signal (R-Y), and the second of which is responsive to said blue and luminance signals to form at least the difference signal (B-Y); and a pair of voltage controlled amplifiers respectively responsive to said differential amplifiers, the first of which is responsive to (1) the (R-Y) difference signal and (2) the first of said two control signals to form a (R-Y) sin theta function and the second of which is responsive to (1) the (B-Y) difference signal and (2) the second of said two control signals to form a (B-Y) cos theta function; and means for combining said last two mentioned functions to form said (R-Y) sin theta + (B-Y) cos theta signal.

Claim 6

Circuitry as in claim 4 where said control means includes a ganged sine/cosine potentiometer.

Claim 7

A chroma-keying system for providing a special effects signal in accordance with the presence of a desired color from a color television camera or other similar source which produces at least three nonencoded color signals such as red (R), green (G), and blue (B) signals, said system comprising: at least two video signal sources each producing nonencoded signals such as red (R), green (G), blue (B) and luminance (Y) signals; at least two encoder means respectively responsive to said two video signal sources, each encoder means producing encoded video signals; a multiposition electronic switch having at least two stable positions respectively corresponding to said two encoders; output means responsive to said switch, said switch connecting one or the other of said two video signal sources to said output device depending on the position of said switch to thereby create at said outpUt device special effects; keying means for controlling the position of said switch, said keying mean, having a threshold level associated therewith; adjustable filter means responsive to said source of nonencoded color signals for developing a keying input signal which corresponds to said desired color, said keying signal being applied to said keying means and causing said switch to change from one of its stable positions to the other whenever said keying signal crosses the threshold value of said keying means; and control means for adjusting said filter means so that said desired color may be selected.

Claim 8

A chroma-keying system for providing a special effects signal in accordance with the presence of a desired color from a color television camera or other similar source which produces at least three nonencoded color signals such as red (R), green (G), and blue (B) signals, said system comprising: at least two video signal sources each producing nonencoded signals such as red (R), green (G), blue (B) and luminance (Y) signals; at least two encoder means respectively responsive to said two video signal sources, each encoder means producing encoded video signals; a multiposition electronic switch having at least two stable positions respectively corresponding to said two encoders; output means responsive to said switch, said switch connecting one or the other of said two video signal sources to said output device depending on the position of said switch to thereby create at said outpUt device special effects; keying means for controlling the position of said switch, said keying mean, having a threshold level associated therewith; adjustable filter means responsive to said source of nonencoded color signals for developing a keying input signal which corresponds to said desired color, said keying signal being applied to said keying means and causing said switch to change from one of its stable positions to the other whenever said keying signal crosses the threshold value of said keying means; and control means for adjusting said filter means so that said desired color may be selected.

Claim 9

A system as in claim 6 where said control means includes means for developing at least two control signals, which are respectively 90*out-of-phase with one another, and where said filter means includes: matrix means responsive to said red, green, and blue signals from said source of nonencoded color signals to produce red, blue, and luminance signals; means responsive to (1) said last-mentioned red, blue, and luminance color signals and (2) said two control signals for producing a signal having the form (R-Y) sin theta + (B-Y) cos theta where theta is a function of said control means and corresponds to said desired color; and whereby said filter means causes the desired color signal to be maximized with respect to other color signals and thus, the filter means acts as a chromatic filter, the ''''pass band'''' of which may be positioned anywhere in the color spectra by said control means.

Claim 10

Circuitry as in claim 7 including exponential amplifier means for increasing the selectivity of said filter means by further increasing the amplitude of said desired color signal with respect to said other color signals.

Claim 11

Circuitry as in claim 7 where said filter means includes: at least two differential amplifiers, the first of which is responsive to said red and luminance signals to form at least the difference signal (R-Y), and the second of which is responsive to said blue and luminance signals to form at least the difference signal B-Y); and a pair of voltage controlled amplifiers respectively responsive to said differential amplifiers, the first of which is responsive to (1) the (R-Y) difference signal and (2) the first of said two control signals to form a (R-Y) sin theta function and the second of which is responsive to (1) the (B-Y) difference signal and (2) the second of said two control signals to form a (B-Y) cos theta function; and means for combining said last two mentioned functions to form said (R-Y) sin theta + (B-Y) cos theta signal.

Claim 12

Circuitry as in claim 6 where said control means is remotely located from said filter means.