Abstract: Apparatus and method for chroma noise reduction in a quadrature modulated color television signal path carries out the steps of detecting a chroma signal noise component in the path; detecting predetermined signal characteristics in the path; generating a control signal as a function of the detected signal characteristics wherein the signal characteristics include at least one of: luminance component amplitude, luminance component level transition, and a combination of simultaneously occurring conditions in luminance and chrominance signal components in the path; applying the control signal to separate chroma signal component noise from the predetermined signal characteristics; and subtracting the separated chroma noise in time coincidence with the color television signal in the path, whereby chroma noise is reduced from the signal path without bandwidth reduction.

Abstract: Method and apparatus for controlling operation of a time domain noise reduction system in a color television picture signal path by: detecting spatial picture characteristics in the path and detecting occurrence of temporal picture changes on a field by field basis, generating a control signal in relation to the detected spatial and temporal picture characteristics and applying the control signal to control time domain operation of the noise reduction system.

Abstract: A color television processing system enhances aperiodic transitions occurring in a quadrature modulated subcarrier by deriving a control signal from simultaneously occurring aperiodic transitions in the baseband of the carrier, such as luminance (or from chrominance in the absense of an effective luminance transition) without demodulation of the chroma subcarrier. The system includes an input, a delay match for delaying a first component of the modulated subcarrier signal by a predetermined amount, a one-half period delay for delaying a second component of the modulated subcarrier signal by half the period thereof, and a first adder for combining in equal amounts a third component of the modulated subcarrier with the delayed second component thereof to provide a transition envelope. A control generator receives the baseband signal and chroma and derives a control signal from transitions occurring in the baseband or in chroma in the absence of baseband transitions.

Abstract: A method for automatic control of non-linear image processing of a television signal subjected to degradation upon passage through a quality degrading medium is disclosed. The processing is of the type including at least one of image enhancement, and noise, ringing and interference reduction within the television signal. The method includes the steps of:a. generating a pilot signal having an amplitude and frequency selected to be representative of video transitions most susceptible to degradation during passage through the medium;b. adding the pilot signal to the television signal prior to its passage through the degrading medium and before any prepassage signal processing takes place;c. passing the television signal through the degrading medium;d.

Abstract: The system includes a recirculating delay line signal path which feeds a fractional component of delayed chroma to a summing junction where it is combined in proper phase with undelayed chroma and the composite is ordinarily put out. In the event of a detected vertical transition in the luminance channel, a control signal is generated in proportion to the amplitude of the detected transition. The control signal is used to switch the output over to the input chroma in proportion to the amplitude thereof. The vertical transition may be detected in luminance or in chrominance, or both in which case the control signal is a combination of the two. The chrominance transition control signal may be inhibited in the absence of chroma in the combed chroma path.

Abstract: A low level television transition signal booster offsets low level video transitions by a predetermined amplitude pedestal prior to the passage of the video through a path in a television system characterized by the unwanted loss of small detail information in order to correct in advance this expected loss of details. The low level signal booster includes a linear signal main path from an input to an output and a low level signal expansion circuit connected in parallel to the linear signal path which generates and adds a nonlinear signal complement which when combined in proper time relationship with a low level video transition signal below a predetermined value increases the instantaneous amplitude thereof generally by the amount corresponding to the pedestal. The signal complement is generated from the low level video transition signal, yet it is not generated for any video transition signals lying above the predetermined value.

Abstract: An improved method and system for separating chrominance and luminance information in a quadrature modulated color television signal and similar periodic signals is disclosed. A comb filter selectively separates chrominance and luminance components from the video signal and provides a combed chrominance output and an adaptively combed luminance output. A low frequency luminance vertical transition detector is connected to an input and detects vertical amplitude transitions occurring at adjacent horizontal scanning lines and produces a first switching signal independent of the direction of a particular transition. A second transition detector detects the simultaneous occurrence of transitions in chrominance and high frequency luminance in either direction above predetermined minimum threshold values to provide a second switching signal.

Abstract: Chrominance and luminance components of a quadrature modulated color television signal are separated by a comb filtering system which includes a chroma separation circuit connected to an input and an adaptive luminance separation circuit also connected directly to the input. The chroma separation circuit includes a one line delay line and a high pass filter connected in parallel therewith. The delay line and the high pass filter are connected to a first subtractor which combines the inputs to provide a comb filtered chroma output. The adaptive luminance separation circuit includes a threshold circuit connected to an output of the chroma separation circuit. The threshold circuit puts out only those portions of separated chroma which exceed a predetermined threshold amplitude. A limiting amplifier connected to the threshold circuit puts out amplitude limited signals of the same phase and polarity as the portions put out by the threshold circuit only when they exceed the predetermined threshold level.

Abstract: A bidimensional noise reduction system for processing a television video signal includes a vertical dimension noise reduction system having a first adjustable threshold coring circuit and a horizontal noise reduction system having a second adjustable threshold coring circuit.

Abstract: A system of shortening transition time of transitions occurring in video signals is disclosed which includes circuitry for multiplying a function of the full wave rectified first differential of the input video signal by a function of the second differential of the input video signal and then adding the waveform resulting from such a product to the properly delayed input signal to provide a crispened output video signal. The system may be provided to crispen the luminance and chroma signals of a color television video signal. A system for shortening transitions of low bandwidth chroma information with higher bandwidth luminance information is also disclosed.