Abstract: A two-dimensional contour enhancement is performed along a plurality of lines on a two-dimensional frequency characteristic chart, the line intersecting with each other at middle points between successive color cross generating regions and not passing through an origin. Then, the contour enhancement can be carried out in a frequency region of 3-4 MHz in which a visual effect of contour enhancement appears most effective, while the enhancement in the cross color generating regions can be suppressed.

Abstract: A method and circuit for reducing distortion of low level signals by efficiently separating noise and signal components using correlativity between respective red (R), green (G) and blue (B) channels and the amplitudes of the detail components. The detail enhancement method includes extracting detail components, determining signal/noise, cancelling noise or enhancing details and outputting a detail-enhanced image signal. Even if a high-pass frequency component of the input signal is smaller than a critical value, the input signal is accurately separated as a signal component or a noise component. The signal is cancelled only when the input signal is classified as a noise component.

Abstract: An image quality correction circuit having a variable gain amplifier for amplifying an extracted high-frequency component of a luminance signal in such a manner that the gain thereof is increased when detected color density is high, and is reduced when the detected color density is low, and a slice circuit for slicing the outputted amplitude of the variable gain amplifier at a prescribed value, wherein a corrected luminance signal is obtained by combining an image quality correction signal outputted from the slice circuit with the luminance signal to be corrected.

Abstract: A digital filter for picture data is disclosed which has a first low-pass filter having relatively steep cut-off characteristics for filtering input digital picture data, a second low-pass filter having relatively moderate cut-off characteristics for filtering input digital picture data, a mixing unit for mixing digital picture data filtered by the first and second low-pass filters, a step detecting unit for detecting changes in step-like values of the input picture data, and a control unit for controlling the mixing ratio of the digital picture data from the first and second low-pass filters by the mixing unit based on step detection outputs of the step detection unit. There is also provided a digital filter system for color picture data having the digital filter for each color.

Abstract: A color signal processing system for a color television receiver which can improve the transition characteristic of a color difference signal, using the transition region of a luminance signal. The system includes a differentiator for differentiating the transition region of an input luminance signal, and a color difference signal processor for processing an input color difference signal by controlling the transition region of the color difference signal in accordance with the differentiated luminance signal. Thus, the transition characteristic of the color difference signal is compensated for in proportion to the transition characteristic of a luminance signal.

Abstract: An image quality correction circuit having a variable gain amplifier for amplifying an extracted high-frequency component of a luminance signal in such a manner that the gain thereof is increased when detected color density is high, and is reduced when the detected color density is low, and a slice circuit for slicing the outputted amplitude of the variable gain amplifier at a prescribed value, wherein a corrected luminance signal is obtained by combining an image quality correction signal outputted from the slice circuit with the luminance signal to be corrected.

Abstract: A color signal processor in which a color subcarrier is multiplied with either a signal harmonic or a phase shifted harmonic of a low frequency chrominance signal, depending on whether the R-Y axis of the chrominance signal is inverted. Band pass filtering extracts an arithmetic carrier signal resulting from the multiplication. The low frequency chrominance signal is multiplied by the extracted arithmetic carrier, and band pass filtering removes both upper and lower side band components generated in accordance with the low frequency chrominance signal multiplication. Various configurations of the above invention eliminate the need for a circuit inverting the R-Y axis, simplifying the structure of color signal processors and related devices. In addition, since no resonating circuit is used, the invention can be effectively implemented in an integrated circuit.

Abstract: A method of improving the sharpness of horizontal edges of an image that has been vertically scaled. The scaled signal, which represents a series of pixel values, is used to derive an aperture correction value (41-46), which is determined by the scaling ratio and an edge factor. This aperture correction value is added to the scaled signal (47), resulting in enhanced pixel values at edges.

Abstract: A video-scrambling system induces a random wobble i.e., time shifting, in the location of active portion of the video frame, without affecting the horizontal sync signal and colorburst in each video line, thus providing both security and concealment. The security is enhanced by filling in the gap between the nominal beginning of active video and the actual beginning of active video with a synthesized video signal which replicates the adjacent active video using a digitally generated filling pattern. Also, a random noise overlay further conceals the location of the gap. Additional concealment is provided by wiggling in time the location of the horizontal sync signal using one or two frequencies and also by randomly altering the location of the vertical sync signal. The NTSC digital encoding in accordance with the invention is simplified by using only two channels, chrominance and luminance, and by a heterodyne circuit for chrominance stability.

Abstract: A video signal processor controls aperture correction of the video signal by detecting the occurrence of particular colors in the image produced by the video signal. The particular color, for example, fleshtone, is detected as a ratio of the amplitude of an in-phase color signal and the magnitude of its corresponding quadrature phase color signal. This defines a range of color phases which are classified as the particular color, regardless of their saturation. The detected color is converted into a control signal which changes the amplitude of the aperture correction signal. In one embodiment the control signal has a value of zero if the detected color is within the range of color phases and a value of one otherwise. This control signal is used as a multiplier for the aperture correction signal. In another embodiment, a second range of colors is defined around the defined range.

Abstract: A vertical contour correcting circuit that provides contour correction of a luminance signal at a horizontal color transition area of an image, thereby minimizing dot interference at the color transition area of a reproduced image. The vertical contour correcting circuit includes a vertical band-pass filter which outputs a level difference signal. The level difference signal is delayed to produce a first delay signal. The first delay signal is delayed to produce a second delay signal. An intermediate value signal is determined from the level difference signal, the first delay signal, and the second delay signal. The intermediate value signal and the first delay signal are added together so that their carrier color signal band components are canceled out.

Abstract: In a high definition flying spot telecine, noise from photomultiplier tubes and afterglow correctors reaches unacceptable levels at high frequencies. The circuit illustrated applied a conventional gamma correction to low frequency components (at 32) but applies a non-linear characteristic to the high frequency components (at 36). The characteristic is chosen to provide the optimum noise performance for positive or negative film. The two parts of the signal are then recombined by adders 40. High frequency processing is carried out on a multiplex of the R, G and B components to reduce complexity (at 16).

Abstract: An improved horizontal contour emphasizing signal processor is provided with a detector to detect a period during which luminance signal changes are produced, a generator to generate a rectangular-wave signal during this period, and a multiplier for multiplying a first horizontal contour emphasizing signal derived from the luminance signal to the rectangular-wave signal to generate a second horizontal contour emphasizing signal, and in this case, a preshoot is added to the input luminance signal waveform at the starting part of a radical waveform change and an overshoot is added at the ending part of the waveform change in order to perform finer horizontal contour emphasizing.

Abstract: A color video signal detector that detects the color level and the color phase of a color video signal includes a differentiating circuit that differentiates a color video signal to detect edges in the color video signal, a switching IC that holds values of the color video signal at times after a given time interval from the edges, a circuit that counts the order of the edges and extracts the value of the color video signal at every count, and a microcomputer that measures the extracted values of the color video signal.

Abstract: An anti-distortion device, connected downstream of a transmitting device (2) with a determined transmission bandwidth for transmitting a input signal (Se) with signal jumps (3), wherein the delay time (Tv15) of the delay element (15) is such that the front slope (24) of the detection signal (S18) of the second signal jump detector (18), produced when a slope (4) of the useful signal (Sa1) is detected, is at least partially located in the time range (T25) of the trailing edge (25) of the corresponding detector signal (S17) of the first signal jump detector (17), that the delay time (Tv11) of the delay element (11) is equal to half the period (T5) of the overshoot (5) superimposed on the useful signal, and following the signal slope (4) of the transmitted signal (Sa1), and that the delay element (10) is connected between the output (1) of the transmitting device (2) and the input (11.1) of the delay element (11).

Abstract: A chrominance transition corrector for restoring chrominance transitions after they have been degraded by a limited bandwidth channel converts input luminance and chrominance components, which represent a video image, from the time to the frequency domain. Correction coefficients are determined from a low frequency portion of the converted luminance component and the converted chrominance components. Corrected high frequency portions of the chrominance components are generated from the correction coefficients and a high frequency portion of the converted luminance component. The resulting converted and corrected high frequency portion of the chrominance components are then converted back to the time domain to produce chrominance output components, the chrominance transitions having been corrected.

Abstract: In an image pickup apparatus having a low-pass filter for detecting a luminance component of an image pickup signal and a band-pass filter for detecting a contour component of the image pickup signal, a digital system for performing a digital signal processing action is arranged to have the low-pass filter and the band-pass filter not cascade-connected to each other. The arrangement is such that the signal processing action is performed without bringing about any spurious contour, any deterioration in frequency characteristic, etc., due to place cancelling peculiar to a digital system. The apparatus reduces the possibility of deterioration of images, permits simplification of circuit arrangement, permits reduction in electric energy consumption and in scale of the circuit, and thus facilitates adoption of an integrated circuit arrangement.

Abstract: In video signal processing circuitry detail enhancement is done on each of three color channels in response to the detail information, the enhancement of the detail in each color channel being done in reliance on separated high-spatial-frequency information originally contained in one or more of the channels. The high-spatial-frequency information is separated by differentially combining a fullband video signal with that signal as filtered by a cascade connection of vertical lowpass filter and horizontal lowpass filter.

Abstract: Horizontal and vertical peaking signals are separated from a video signal by combining variously delayed responses to the video signal. A cross-fader combines the separated horizontal and vertical peaking signals in proportions determined by a cross-fader control signal. A correlator responds to ones of the variously delayed responses to the video signal for generating an output signal representative of the relative degrees of vertical and horizontal correlation in the video signal. The correlator output signal addresses a read-only memory that supplies the cross-fader control signal. The adaptively generated peaking signal is suitable for adjustably peaking a luminance component extracted from the video signal, where that video signal is a composite signal also including a chrominance component.

Abstract: A waveform shaping apparatus in which no unrequired waveform shaping operation is performed even if its sensitivity is enhanced is provided. A signal (A) to be shaped in waveform is delayed by delay circuits (1 and 2) to produce signals (B and C). The signals (A, B and C) are applied to an original correction signal generating means (200a) and a control signal generating means (100a) to produce original correction signals (Ka and Kb), and control signals (Ha and Hb), respectively. A control circuit (13) selects the original correction signals (Ka and Kb), or a value "0" in accordance with the control signals (Ha and Hb) to generate a quasi-correction signal (L). The signal (L) is multiplied by a specified coefficient in a coefficient multiplier (14) to produce a correction signal (M), and the correction signal (M) is added to the signal (B) in an adder (5) to obtain an output signal (N) which has been shaped in waveform.

Abstract: A chroma noise reduction device comprises an 1H delay element, first and second variable delay units, variable amplifier, first and second adder amplitude restricting circuit, first and second subtracters and first, second and third phase detectors. The first phase detector compares the phases of a delay signal of a second variable delay unit and chroma signal supplied to the second variable delay unit and controls the second variable delay circuit to have the phase of the delay signal 90.degree.-delayed relative to the chroma signal. The second phase detector compares the phases of the delay signal and output signal of the variable amplifier and controls the phase of the first variable delay unit in response to a result of comparison. The third phase detector compares the phases of a sum signal of the delay signal and output signal of the variable amplifier and a difference signal of the delay signal and output signal of variable amplifier and controls the amplitude of the variable amplifier.

Abstract: A circuit and method for shortening the transition time of sharp color transitions in color television signals. The invention includes a pattern recognition circuit and method which directly and efficiently recognizes color transitions within a predetermined range. The disclosed embodiment of the invention utilizes a filter to output its step response to the pattern recognition circuit which outputs a control signal whenever the color signal rise or fall time does not fit a predetermined pattern. When the pattern recognition circuit recognizes the step response, it directs a hold circuit to output a previous color signal for a predetermined time period before allowing the transition to proceed, thus shortening the transition time.

Abstract: A video signal processing system including a reproducing or receiving circuit which is responsive to a recorded or transmitted video signal having a motion signal modulated at a first frequency mixed with a chroma signal modulated at a second frequency, wherein the reproducing or receiving circuit includes a chroma/motion C/M separating circuit for separating the motion signal from the chroma signal, and a vertical low-pass filter for passing vertical low frequency components and removing vertical high frequency components to eliminate redundant components existing in the vertical high frequency component of the video signal. The system can be adapted to any video system which carries out three-dimensional video processing, using a motion signal, to enhance high resolution.

Abstract: A signal processing system is disclosed in which the image resolution is improved by extending the horizontal frequency bands of separated luminance and chrominance signals and compensating the contour of an input image signal, the frequency band of the input chrominance signal is extended by the chrominance signal processing part, and by the extension of frequency band, the transition time of the high frequency components of the image signal is reduced for the high frequency image signal processing and reducing the short data processing time.

Abstract: A color video camera includes circuitry which generates a peaking signal that is applied to each of the color signals to enhance high-frequency components of the video signal relative to low-frequency components. The circuitry adds high-frequency components from the green video signal, as the peaking signal, at instants when the amplitudes of the green and red color signals are approximately equal. If there is a significant difference between the amplitudes of the red and green video signals, however, a combination of the high frequency components of both of these signals is used as the peaking signal. In one exemplary embodiment of the invention, the peaking signal includes in-band horizontal and vertical contour signals and out-of-band aperture correction signal.