Abstract: In a luminance channel of a color television receiver, a luminance signal is conveyed to the input of a delay line via first and second series connected source resistors. A series tuned trap tuned to the chrominance subcarrier frequency is coupled between the junction of the first and second resistors and a point of reference potential. The coaction of the first and second source resistors and the trap results in a significant reduction in frequency dependent source impedance variations at the input of the delay line.

Abstract: In a method for transmission of color television signals, at least two color information containing signals are coded using code elements comprised of a half period or a full period of a sine wave, the sequence of code elements forming at least one essentially sinusoidal code signal stream. In one embodiment, the code elements form binary code words for conveying different types of information, as hue and saturation of a color picture element. Alternatively, each code element may have an amplitude related to the value of the information to be transmitted, as saturation of a specific primary color. Each code word may comprise a plurality of portions related to different types of information, as different primary colors, audio information and the like. Two code signal streams each forming a sine wave of the same predetermined frequency may be phase displaced by 90 degrees, superimposed and employed in a composite video signal e.g. instead of and at the same frequency as an usual color subcarrier wave.

Abstract: A chrominance signal processing system includes a variable gain amplifier capable of effecting gain control for amplifying a carrier chrominance signal and an A/D converter for effecting an analog/digital conversion of an output of the variable gain amplifier. A demodulator demodulates an output of the A/D converter into two chrominance signals on two demodulation axes which are apart by 90.degree. from each other. One of the chrominance difference signals is disposed at a right angle with respect to a vector of a burst signal of the carrier chrominance signal and the number of bits of the two chrominance difference signals are chosen such that the number of bits of the one chrominance difference signal disposed at right angles with respect to the burst signal vector is smaller than the number of bits of the other of the two chrominance difference signals.

Abstract: A frame comb filter separates a luminance signal from a composite video input signal for display on every other line of a progressively scanned display. The filter includes a tap for providing a field delayed luma signal and an interpolator for providing a frame comb filtered and interpolated luma signal. A selector switch selects the field delayed luma signal for display on the intermediate lines of the display when the vertical detail content of the input signal is greater than a minimum threshold value and there is little or no interframe motion and selects the frame comb filtered and interpolated luminance signal for display otherwise thereby providing enhanced vertical detail and reduced field motion artifacts for displayed images.

Abstract: A color-picture reading apparatus comprises blue, red-purpose, and green-purpose fluorescent lamps, a red filter in front of the red-purpose lamp for solely passing the red radiation, a green filter in front of the green-purpose lamp for solely passing the green radiation, and a circuit for subsequently switching on and off the three lamps. Both the red filter and the green filter comprise a first filter for filtering the short wavelength radiation and a second filter for cutting the long wavelength radiation. The first filter is a glass filter and the second filter is an interference filter. All of the three lamps have a short afterglow time.

Abstract: In memory-based video signal processing systems such as frame recursive filters, for example, system performance is dependent upon critical timing relationships between incoming signals and delayed signals produced from the memory. Video signal from various sources, e.g. VTR's, tend to have jittering time bases that generally have prevented the use of such memory-based processing systems. The jittering signals may be standardized, in sampled data format, by effecting adaptive signal delays responsive to a measure of the relative phase of the sampling clock with respect to horizontal synchronizing pulses. The phase measure is used to control an interpolator which combines successive samples in proportions to develop sample values that should have occurred at the sample times had the signal not been jittering.

Abstract: In an encoding circuit for the S.E.C.A.M. color television standard a signal value is added to each one of two line-sequential color difference signals to determine the quiescent frequencies. The modulating signal containing the color difference signals is subjected to double sided amplitude limitation. The ratio of the level difference between the limitation limits to the difference between the added signal values is substantially constant. The signal path for the modulating signal to the FM-oscillator comprises a controllable amplifier, limitation being effected first followed by amplification.

Abstract: A method for converting line sequential color signal to simultaneous signal is attained by selecting two color signals alternately every one horizontal scanning period. The color signals are applied to a balanced modulator. Two carriers with different phases are alternately switched every one horizontal scanning period and supplied to the balanced modulator to form carrier color signals with different phases every one horizontal scanning period. There are two carrier color signals of which one is a through carrier color signal and the other is produced by delaying the phase of the through carrier color signal by one horizontal scanning period then phase-shifting by 180 degrees. In an alternative embodiment, two balanced modulators are employed and a delayed replica of the color signals is applied to the second of the two modulators. Two carrier color signals are outputted from the two balanced modulators, and are mixed to produce simultaneous signal.

Abstract: A method for color correction in the process for reproducing a picture in which color separation picture signals obtained by photoelectrically scanning an original picture are converted into picture signals which correspond to four printing color inks including a black ink therein to produce respective reproduction pictures for plate making corresponding to each of the color inks. A picture signal which corresponds to a black ink is produced according to gray color components obtained from B, G and R signals of the original picture, and according to chromatic color components obtained by subtracting neutral color components from said B, G and R signals. Color separation picture signals corresponding to other color inks, and deficiency in reproduction density of the black ink to be used in a black print is corrected by said other three color inks.

Abstract: Apparatus for producing a color image signal having first and second color components, comprises an image sensor having a regular array of image sensing elements with a regular array of first and second colored filter elements registered thereon for producing a sampled color image signal having first and second color components, a lens for forming a color image on the image sensor, an optical device for displacing the first color component of the image with respect to the second color component by an amount equal to an integral number of image sensing elements such that neighboring image sensing elements having first and second colored filter elements sample the same portion of the image, and a delay device for synchronizing the color components of the image by delaying the first color component with respect to the second color component of the sampled color image signal produced by the image sensor by an integral number of image sensing element sample periods corresponding to the displacement of the first co

Abstract: A video signal recursive filter includes circuitry for controlling the integration time of the filter. The control circuitry develop a motion-threshold value responsive to the noise content of signal differences developed by subtracting a processed signal, delayed by a frame period, from an incoming video signal. The signal differences are compared against the motion threshold to develop motion signals indicating the history of image motion for each picture element. Circuitry responsive to the signal noise content develops a signal which is coupled to the motion signals to form address codewords that are applied to a ROM programmed with predetermined control signals for establishing the integration time of the recursive filter.

Abstract: A digital television receiver, which uses a comb filter to separate the luminance and chrominance components of composite video signals, includes an adaptive band-pass filter for processing the comb filtered chrominance signals. Comb filtered chrominance signals may include luminance vertical detail information at the relatively high frequencies also occupied by chrominance information. The adaptive band-pass filter is controlled to have a narrow bandwidth when significant amounts of this relatively high frequency vertical detail information are present and to have a wide bandwidth otherwise. Consequently, the bandwidth of the chrominance signal provided by this filter is restricted only when it is necessary to prevent distortion, and vertical detail is added to the luminance signal only when it is not likely to be contaminated with chrominance information.

Abstract: Methods of electronically enhancing one or more color components (C, Y, M) which together represent the chromatic components of a pixel of an image are described. The methods comprise subtracting from each color component respective quantities which when combined correspond to a grey level (4) to generate reduced color components. These reduced color components are then multiplied by a factor and the modified reduced color components are then added back to the subtracted quantities or to the original color components to generate enhanced color components (13,14), whereby the factor is chosen such that the hue of the original pixel is not substantially changed after enhancement. In one method, the magnitude of the maximum reduced color component is determined and a factor is chosen which is related to the determined magnitude. In another method, the color components are ranked in order of magnitude and compared to derive two equivalent color component values.