Abstract: A chroma modulation method for extending the bandwidth of baseband plural chroma components of an NTSC format quadrature modulated chroma subcarrier color television signal, such as I and Q components, with reduced susceptibility to ringing and with compatibility with existing NTSC color television receivers comprises the steps of: separating the baseband I and Q components into narrow bandwidth segments and extended bandwidth portions not including the narrow bandwidth segments; q u a d r a t u r e modulating the narrow bandwidth segments into a narrow band double sideband quadrature modulation envelope about the subcarrier frequency; alternately selecting and putting out the extended bandwidth portions of the I and Q components on a basis related to a predetermined scanning period of the television signal, such as the field period; modulating the alternately selected extended bandwidth portions at the subcarrier frequency to produce a lower single sideband; and, combining in corrected time relationship the

Abstract: An encoding method for controlling the operation of a luminance comb filter encoder for processing a quadrature modulated subcarrier color television signal includes the steps of:separating spectral components at the vicinity of the subcarrier quadrature modulation from a full bandwidth luminance signal,separating chroma spectrum components from the separated spectral components by comb filtering,multiplying the separated chroma spectrum components by a control signal to provide a product,subtracting the product from the full bandwidth luminance signal to provide a comb filtered luminance signal, andgenerating the control as a function of motion detected to be present within the picture image of the full bandwidth luminance signal.

Abstract: A method and apparatus are provided for reducing transmission path noise within a video signal so as to provide a noise reduced picture image upon a display. The method comprises the steps of:a. extracting low level picture details and the transmission path noise from the video signal,b. recirculating a fractional component of the extracted low level picture details and the transmission path noise,c. combining the recirculated fractional component with the extracted low level picture details and the transmission path noise to cancel the extracted low level picture details and thereby separate the transmission path noise,d. subtracting the separated transmission path noise from the video signal in the absence of motion of the picture image thereof in order to noise reduce non-moving portions of the picture image of the video signal, ande.

Abstract: A television signal processing system includes a source of video images for providing luminance and chrominance components of the video images by generating and putting out scan lines. The source includes a low level horizontal domain detail processor connected for boosting low level horizontal transitions of the luminance component put out by the source below a predetermined threshold level. The system typically includes a signal-degrading path such as one characteristic of transmission or recording. The signal is passed through the degrading path to a display unit. A line doubler is preferably, although not necessarily, included in the display unit for doubling the number of decoded scan lines of the signal and for putting out scan line doubled luminance and chrominance components. A display image processor is connected to the line doubler and provides horizontal domain transition high level enhancement for enhancing horizontal domain transitions having amplitudes above the predetermined threshold level.

Abstract: A video pixel interpolator generates interpolation pixels from incoming picture image pixels for use within a television picture scan line doubler system. The interpolator includes a temporal median filter for generating an interpolation pixel by selection of the median one of a plurality of temporal pixel samples derived from incoming video, an intra-field averager means for generating an intra-field pixel average, and a switch connected to switch an input to a line doubler of the system between outputs of the temporal median filter and the intra-field averager in response to detection of pixel motion within the picture image. Improved motion detection, and multi-channel processing are also included within the present invention.

Abstract: A television line doubler having a video pixel interpolator and a multi-component motion detector including at least one frame-recursive component for detecting a motion value in the area of the pixel to be interpolated. A second switch switches its output to an interpolated pixel time compression circuit in accordance with the detected motion value. The second switch and the motion detector provide a proportional switch with an onset at approximately 2 to 5 IRE units of motion value and operating in accordance with the absolute amplitude of the motion value. Full switchover to the intra-field interpolator means occurring at approximately 5 to 15 IRE units of motion value amplitude. The motion detector stretches the detected motion to a predetermined number of adjacent pixel location in the line domain and a recirculation loop enables a component of motion to be recirculated.

Abstract: A method generates a reinforcement signal for transmission in scan lines within a vertical blanking interval of a predetermined television video signal, and includes the steps of: randomizing the reinforcement signal in accordance with a predetermined key, adding the randomized signal to be within the vertical blanking interval of the video signal to produce a combined signal, and sending the combined signal through a television transmission path. In a preferred embodiment the video signal is in accordance with an aspect ratio which is greater than four to three, and the combined signal may be displayed on a conventional television display which displays an increased vertical blanking interval as horizontal dark bars at the top and bottom of the television picture and wherein the reinforcement signal within the bars is not coherent with any picture image being displayed. Within such displays, gamma correction of the reinforcement signal is useful.

Abstract: A television signal is provided with a variable aspect picture display ratio by the steps of generating and putting out the television picture signal in accordance with a predetermined signal format in a manner in which a selectable horizontal to vertical aspect ratio is governed by the number of horizontal scan lines used to scan picture content, and generating and putting out with the television picture signal a marker signal indicative of the aspect ratio selected. A conventional television set displays narrow aspect ratio transmissions as full screen displays and wide aspect ratio signals with top and bottom black bands, usually masked by overscan. A new television set receives the television signal and marker signal indicative of the aspect ratio selected.

Abstract: Improved separation of audio and video spectra carried upon spectrally separated audio and video carriers within a television transmission channel leading to a television receiver is realized in a method which includes the transmission steps of: obtaining a high frequency luminance component at the vicinity of the audio carrier offset from the video carrier from a full bandwidth baseband luminance signal received from a video source; limiting the amplitude of luminance energy groups within the high frequency component to be below a predetermined amplitude level; combining the amplitude limited high frequency component into the full bandwidth luminance signal in a manner which provides a composite luminance signal having amplitude limited high frequency energy groups at the vicinity of the audio carrier; adding video synchronizing information to the composite luminance signal to provide a signal video modulation signal; modulating said video carrier with said single video modulation signal; combining the video

Abstract: A method for reducing noise and interference artifacts in a television system including a transmissiion end for transmitting a quadrature modulated color subcarrier television signal through a degrading medium and for display at a reception end, the method includes the transmission steps of: dividing the television signal into two paths, a main path and a preemphasis path, developing a main path television signal component in the main path, deriving a preemphasis component from the television signal in the preemphasis path in accordance with at least one predetermined preemphasis criterion, multiplexing the preemphasis component from the preemphasis path into a single spectrum including the main path television signal component, the single spectrum having a bandwidth substantially no greater than that required by the main path television signal without substantial intermixture of the preemphasis component and the main path television signal, and passing the single spectrum through the degrading medium; and co

Abstract: A method is disclosed for reducing bandwidth of a chrominance path to reduce cross-color artifacts in a quadrature modulated color television signal. The method includes the steps of detecting the level of a chrominance component of the signal; developing a control signal from the detected chrominance component level; and, controlling the bandwidth of the chrominance path in accordance with the control signal so as to reduce bandwidth only when chrominance component is at a level below a predetermined threshold. The method for developing a control signal may further include the step of eliminating the sign thereof followed by a step for establishing a predetermined minimum threshold value of the absolute value chrominance level below which the control signal is not generated.

Abstract: A method for controlling reduction of a ghost image present in a main path baseband television video signal includes the steps of deriving a main path reference pulse and ghost image of the pulse from a successive series of pulses and ghost images of the pulses present during the vertical blanking interval of a present field of the video signal, the derived ghost image having an amplitude less than the amplitude of the derived main path reference pulse; replicating the derived reference pulse and ghost image at a predetermined repetition rate substantially throughout the useful picture area of the present field interval; generating a signal used for correlation which is delayed in time from the occurrence of the beginning of the present video field; correlating the replicated ghost image with the signal used for correlation to ascertain a location of coincidence in order to provide a correction pulse indicating the delay period and amplitude of the ghost image of the pulse; generating at least two control sig

Abstract: A method for processing a quadrature modulated color television picture signal including a luminance component and a chrominance component to reduce cross-color and cross-luminance artificacts in a resultant signal includes in an encoding process the steps of: comb filtering the quadrature modulated chrominance component in a comb filter structure wherein a number of delays between 2 and 13 is adaptively determined by overlap between chrominance and luminance, and the delay is a predetermined one of line scan period, frame scan period, and frame/line scan periods, to put out a comb filtered chroma component; processing the luminance component by passing the luminance component through two complementary filters both symmetrically centered about a chrominance component subcarrier frequency, one filter comprising a band pass filter and the other filter comprising a band reject filter; comb filtering the luminance signal passing through the band pass filter in a comb filter structure wherein a number of delays be

Abstract: Improved apparent picture quality in film-to-video transfer television systems operating in accordance with an odd ratio between film frame display rate and television scan field/frame rate and wherein the video scan line rate is multiplied by an integer for display at an output television display device is achieved by the steps of:a. transferring each film frame to a television signal of predetermined numbers of even and odd video fields at nominal line scan rate in accordance with a predetermined transfer scheme related to the odd ratio;b. putting the television signal through a transfer medium;c. receiving at a receiver the television signal from the transfer medium;d. selectively passing the received television signal through plural, series connected field period delays to provide an undelayed portion and plural delayed signal portions, the total number of such portions being related to the odd ratio;e.

Abstract: An improved comb filter extracts at least one of chroma and luminance from a quadrature modulated subcarrier color television input signal. The described method implemented by the described apparatus includes the steps of delaying the input signal through a plurality of predetermined delay periods wherein the duration of each delay period is related to line scan period or picture frame period, filtering the undelayed and delayed signals so that energy components of the input signal lying in the vicinity of the chroma subcarrier frequency are passed, thereby providing bandpass filtered undelayed and delayed signals, detecting amplitude and sense of periodic transitions lying in the chroma energy passband, multiplying two of the undelayed and delayed signals by the continuously variable coefficients to produce an error correction signal corresponding substantially to the following approximation:e=1/4(V1-V3)(.vertline.V3+V2-V1+V2.vertline.)wherein .vertline. .vertline.

Abstract: In a television system a transition level signal booster decreases transition time of low level transitions within a video signal without creating artifacts incident to high level transitions within the video signal.

Abstract: A method and apparatus for encoding and detecting a wide band quadrature modulated color television signal which is NTSC format compatible is disclosed. The encoding steps include: generating an amplitude modulated radio frequency carrier; generating a first sideband of the carrier comprising limited bandwidth luminance information and a quadrature modulated chroma subcarrier; adaptively preemphasizing low level signal transitions occurring in extended bandwidth luminance information, and generating a second sideband of the carrier comprising the adaptively preemphasized extended bandwidth luminance information without addition or presence of the chroma subcarrier.

Abstract: Apparatus is disclosed for processing incoming scanning lines of video information having a nominal bandwidth for use with a bandwidth degrading path, such as magnetic tape.A preprocessor includes a preprocessor comb filter for comb filter processing of the incoming scanning lines to assure the presence of spectral gaps between energy groups in the spectrum of the video information. A fold over circuit folds over high frequency video components of the video information about a predetermined folding frequency to provided folded video. A low pass filter filters the resultant folded video to limit the spectrum thereof to be not greatly in excess of one half of the folding frequency.A postprocessor includes an unfolding circuit for unfolding the signal from the path about the predetermined folding frequency.

Abstract: A comb filter for improved cross-color reduction with improved visible diagonal resolution is provided for processing a luminance component of a quadrature modulated color subcarrier television signal in the vicinity of the color subcarrier pass band. The comb filter comprises an input and an output, and has a first path including a delay circuit for delaying the luminance component and a subtraction circuit connected between the input and the output, and has a second path including a chrominance type comb filter, a band pass filter for passing a spectrum in the vicinity of the color subcarrier pass band both being followed by a variable threshold circuit connected to the subtraction circuit. The variable threshold circuit is for inhibiting the signal in the second path below a variable threshold. The variable threshold is derived as a function of at least one of luminance diagonal transition level, chroma level and averaged luminance activity in the spectrum in the vicinity of the color subcarrier.

Abstract: A method is disclosed for reducing cross-color artifacts occuring at a diagonal luminance transition in a quadrature modulated color television signal in which a chrominance component carried on a color subcarrier has been separated from the signal by comb filter processing. The steps of the method are detecting the occurrence of a diagonal luminance transition in the signal; developing a control signal from the detected luminance transition; and, processing the chrominance component under the control of the control signal to reduce the cross-color artifact in the chrominance at the instance of the detected luminance transition.