Abstract: In a color separator circuit, edge detection filters detect an edge encountered in the horizontal direction. When the image signals corresponding to the thus detected edge are processed, selector circuits 12a to 12c select outputs from small-tap-number color separation filters 8a to 8c and 10a to 10c, respectively. When the image signals corresponding to the remaining portion other than the edge are processed, the selector circuits 12a to 12c select outputs from large-tap-number color separation filters 9a to 9c and 11a to 11c, respectively. A ratio calculator circuit 16 calculates, from the luminance signals fed from adder circuits 13a to 13c, the value by which a multiplier circuit 18 performs multiplication. The multiplier circuit 18 multiplies, by this value calculated by the ratio calculator circuit 16, the color separation signals added together by an adder circuit 17 so that, of all the color separation signals of which there are two kinds, those of one kind are vertically interpolated.

Abstract: A luminance (Y) and a color difference (C) signal separator switches filters according to an image and separates a Y signal and a C signal included in a composite color picture signal to eliminate a degradation which would otherwise be involved at a transition point because of the characteristics of the filters. A first weighting circuit calculates the weighted average of the C signals extracted from the composite signal by a comb filter and a three-line comb filter. A second weighting circuit calculates the weighted average of the C signals extracted by the three-line comb filter and a two-line comb filter. When the motion level of the image exceeds a predetermined threshold, a selector selects, as the final C signal, the signal output from the second weighting circuit. When the motion level is equal to or lower than the predetermined threshold, the selector selects, as the final C signal, the signal output from the first weighting circuit.

Abstract: A method and system for performing combing for PAL luma data is disclosed. The combing is performed for a display having a plurality of lines. The display is capable of depicting a frame including a horizontal boundary having a top edge and a bottom edge. A top line of the plurality of lines is at the top edge of the horizontal boundary. A bottom line of the plurality of lines is at the bottom edge of the horizontal boundary. The method and system includes providing a feedback multiplexer, a line delay and a feed forward multiplexer. The feedback multiplexer has a first input, a second input and a first output. The first input is for receiving luma data for a current line. The line delay has a delay input and a delay output, the delay input coupled with the first output. The delay output is coupled with the second input. The feed forward multiplexer has a third input, a fourth input and a second output. The third input is coupled with the delay output.

Abstract: Fixed pattern noise of an analog memory is reduced. Transfer paths of an address selection signal (SL) between an address generation unit (10) and respective storage elements (21) for storing an analog signal are constructed to have a substantially uniform electric characteristic in driving the storage elements (21) by the address selection signal (SL) to such an extent that the output signal of the analog memory is free from fixed pattern noise. A buffer unit (50) for temporarily storing and outputting the address selection signal is provided between the address generation unit (10) and the respective storage elements (21), and the buffer unit (50) is constructed to have an output characteristic substantially uniform between the storage elements (21). Also, lines between the buffer unit (50) and the storage elements (21) are constructed to have substantially the same electric characteristic.

Abstract: An apparatus for separating color and. luminance signals from a composite video signal in consideration of the existence and degree of a motion of the video image. The apparatus includes an output section, a first filter, a second filter, a third filter, a motion detector, a motion estimator, a color selector and a luminance selector. The color and luminance selectors select and output the color and the luminance signal from the output signals of the filters in accordance with the existence and degree of the motion.

Abstract: A decoder for composite video signals is provided which is capable of preventing decreases in resolution at a time of YC (Luminance and color signals) separation from composite signals indicating images having vertical stripes.

Abstract: A digital comb filter for decoding composite video signals into a luminance and a chrominance component. A Fast Fourier Transform (FFT) circuit or a band split filter circuit is used to determine important characteristics of an input video signal without demodulating the video signal. The circuits produce a signature signal by which each of the video lines can be correlated. Signature signals on various surrounding video lines that are of opposite subcarrier phase with the current line are compared to determine similarity and appropriate weighting coefficients for the surrounding lines. If none of the surrounding lines are similar, the comb reverts to a band split filter to form chrominance. A noise measure circuit determines an error signal input used to adjust the weighting coefficients as the noise level increases or decreases. Multiplexer combines high pass and low pass taps of a band split filter into a single data stream.

Abstract: A method and circuit thereof for detecting uncorrelated lines of chrominance of a composite video signal. A threshold level for determining whether lines of chrominance are correlated is defined. A comb filter is then used to separate the chrominance information from the luminance information of a composite video signal. In one embodiment, readings for three consecutive scan lines of chrominance are taken. If any of the adjacent scan lines contain the same color information or the difference is less than the threshold level, the scan lines are correlated. Otherwise, the adjacent scan lines are uncorrelated. If the lines are uncorrelated, a band pass filter is used to separate the chrominance component from the composite video signal. If the lines are correlated, the separation performed by the comb filter was appropriate and no other action is necessary.

Abstract: An apparatus for separating luminance and chrominance signals from an NTSC composite video signal includes first through fourth delayers connected to a digital composite video signal in series for delaying input signals each by 1, a first filter for separating a first chrominance signal from signals output from the first and second delayers; a second filter for separating a second chrominance signal from signals output from the second and third delayers, a vertical edge direction detector for detecting a vertical edge direction by receiving signals output from the second and fourth delayers and receiving the digital composite video signal, a multiplexer for outputting one of the first and second chrominance signals based on a signal output from the vertical edge direction, a chrominance signal outputting unit for receiving the output of the multiplexer and then outputting a perfect chrominance signal, and a luminance signal outputting unit for receiving the signal of the second delayer and receiving the chrom

Abstract: A video signal processor which includes a reference signal generating circuit provided with at least an oscillation circuit for generating a reference signal corresponding to a burst signal and a Y/C separation circuit for separating a video signal into a luminance signal and a chrominance signal with an output of the reference signal generating circuit as a clock signal, and uses a microcomputer for controlling the entire operation of the video signal processor. In the video signal processor, an output of the reference signal generating circuit is also supplied to the microcomputer as a clock signal.

Abstract: A method and apparatus for separating a signal uses a low pass filtering in a first direction to produce a signal with a low component and a alias component and then uses a filtering in a second direction to produce a component of a separated signal. The filter has applications in television signal decoding and has other applications.

Abstract: A color television decoder or other signal processor has a gate controlling the passage of a notch filtered chrominance signal. A filter circuit produces a further chrominance signal which serves as the control signal for the gate.

Abstract: Disclosed are an apparatus and a method for YC separation and three-line correlation detection with high accuracy, which allow the YC separator to generate reliable Y signals. The correlation detecting apparatus includes a sub-correlation detector. The detector checks input signals for the presence or absence of vertical correlation, and provides the signals with a judgment “high-correlation exists” or “otherwise”. According to the judgment, the correlation detecting apparatus changes the process; i) when accepted the judgment “high-correlation exists”, the apparatus determines the judgment to be reliable and adopts it as the output, ii) when accepted “otherwise”, the apparatus increases its detecting accuracy and provides the signals with multi-leveled outputs according to the correlation levels. In this way, the main apparatus switches the detecting mode according to the result from sub-correlation detector, with the detecting accuracy greatly improved.

Abstract: A video signal decoder including a comb filter characterised by means for changing the operating mode of the filter progressively. Also, a video signal decoder including a comb filter characterised by means for adjusting continuously the degree of filtering performed by the filter. In one arrangement the decoder comprises an input filter and two signal multipliers wherein one of the multipliers is connected to receive a signal output by the input filter and the other multiplier is connected to receive a signal output by the comb filter wherein operation of the multipliers is mutually interdependent.

Abstract: A composite video decoder that separates digitized composite video signals into luminance and chrominance, demodulates the chrominance signal to its R-Y and B-Y components, removes time base errors, synchronizes the output to the station reference signal and converts three parallel digital signals to a serial digital output signal. A three dimensional digital comb filter, an interpolation circuit for time base correction, a sync error detector circuit, a noise measurement circuit and a means of using the noise measurement level to adapt the other circuits for best operation at various noise levels of the video input signal provide high quality translation from a composite video input to a serial digital interface output (SDI). A digital line recursive filter is used to extract the horizontal synchronizing signal whether the signal is clean or masked by a very high noise level riding on the video signal.

Abstract: A video composite signal is thinned by sub-Nyquist sampling signal to reduce a capacity of a memory, a carrier chrominance signal is separated from the thinned video composite signal by an inter-frame YC separation circuit 13, the first separated carrier chrominance signal is interpolated by horizontal interpolation circuit 25 to reproduce the lost data due to thinning, the interpolation data is compensated by an adding circuit 29 in accordance with a high frequency component in a second separated carrier chrominance signal separated without thinning detected by an intra-field YC separation circuit 16 and high frequency component extraction circuit 28 when an edge is present in the separated carrier chrominance signal from the inter-frame YC separation circuit 13, which is detected by an edge detection circuit 26, the first separated carrier chrominance signal is outputted at the timing corresponding to the sub-Nyquist sampling signal, the interpolation data is outputted at an interpolation timing when the ed

Abstract: A digital comb filter for decoding composite video signals into a luminance and a chrominance component. A Fast Fourier Transform (FFT) circuit or a band split filter circuit is used to determine important characteristics of an input video signal without demodulating the video signal. The circuits produce a signature signal by which each of the video lines can be correlated. Signature signals on various surrounding video lines that are of opposite subcarrier phase with the current line are compared to determine similarity and appropriate weighting coefficients for the surrounding lines. If none of the surrounding lines are similar, the comb reverts to a band split filter to form chrominance. A noise measure circuit determines an error signal input used to adjust the weighting coefficients as the noise level increases or decreases. Multiplexer combines high pass and low pass taps of a band split filter into a single data stream. Line delays delay the current video signal to form two additional lines of video.

Abstract: Apparatus for processing video signals and which can be connected with a personal computer for further processing. An analog to digital converter samples and converts input NTSC composite video signal into digital signal for subsequent processing. A phase-locked loop provides sampling clock signal to the ADC, and also ensures accurate sample phase. Based on a theory that human eye is more sensitive to the luminance component of video signals, a double sampling circuit is included which double samples the luminance component of a video signal to improve the overall resolution of an image.

Abstract: An adaptive signal separation system and method for quadrature amplitude modulated signals that is particularly well-suited for YC separation of a composite television signal. An adaptive approach for separating overlapping signals wherein the adaptive approach selects between notch or equivalent filtering and a comb filtering system, wherein the chrominance is first demodulated to the IQ domain prior to comb filtering. The demodulated comb filtered IQ data streams are then re-modulated to reconstruct the luminance portion of the signal.

Abstract: A comb filter easily implementable as a monolithic LSI without using a large-capacitance capacitor is provided. A comb-like frequency characteristic is realized by two delay circuits for delaying a signal for mutually different amounts of time and an operation circuit for deriving a sum or difference of the outputs thereof. An input select switch selectively outputs, instead of an image signal, a test signal, which is a DC signal having a predetermined amplitude, during a blanking interval of the image signal. A detector controls the gain of a variable-gain amplifier, provided for the output of either one of the delay circuits, in accordance with a difference between the output signal of the comb filter in response to the test signal and a predetermined reference signal. That is to say, the gain of the comb filter is controlled by using a stable test signal as a control signal, instead of a burst signal contained in an unstable image signal.

Abstract: A system and method for compensating against false color from composite video source information detects when there is a diagonal luminance transition (or a cross pattern) and attenuates combed chrominance information to facilitate a reduction in a false coloring effect. A programmable threshold diagonal transition detector generates a multi-level compensation control signal, such as the amount of chrominance reduction or attenuation (in dB) to effectively notch combed chrominance data, based on a detection of a diagonal transition of luminance data among lines of video data. The multi-level compensation control signal is used by a multi-level compensator to attenuate the combed chrominance information from the 2-D adaptive comb filter.

Abstract: A method and system for separating chrominance and luminance information from a composite spectral signal is disclosed. The method and system comprises demodulating the composite signal prior to separation of the chrominance or luminance information to provide a first U subcomponent and a first V subcomponent and then processing and filtering the first U subcomponent and the first V subcomponent to provide a second U subcomponent and a second V subcomponent, respectively. The method and system also includes combining the second U subcomponent and the second V subcomponent to provide the remodulated chrominance information. In so doing chrominance information is provided in which artifacts are substantially attenuated.

Abstract: An output signal of an 1H delaying circuit and a signal received from an input terminal are supplied to a subtracting circuit that forms a comb line filter. Thus, even if a dropout takes place in a luminance signal, not in a chroma signal, the chroma signal can be obtained from an output signal at intervals of 1H. When a dropout takes place, a limit operation of a feedback loop that forms a noise reduction circuit is stopped and the coefficient is increased. This process is performed with a dropout pulse that is delayed by 1H. Thus, the chroma signal can be obtained on the next line of the line having the dropout.

Abstract: A luminance/chrominance (Y/C) signal separating device utilizing motion estimation and compensation. According to the device, the image motion is detected in the unit of a 2.times.2 (sample.times.line) block to separate an NTSC television signal into the Y and C signals. As a result of the motion detection, a three-dimensional Y/C signal separation is performed with respect to a still image, while a three-dimensional Y/C signal separation with the motion estimation and compensation in the unit of the 2.times.2 (sample.times.line) block in a predetermined region of the previous frame is performed with respect to a moving image. A two-dimensional Y/C signal separation is performed with respect to the moving image whose motion is not compensated in the unit of a 2.times.1 (sample.times.line) block in the present frame.

Abstract: In analog color television transmission methods, the transmitted CVBS signal comprises luminance and chrominance signals which have to be separated from one another in a television receiver in order to permit separate further processing. Comb filters can be used for this, a picture contents-dependent controller frequently being worked with which switches over between different filter algorithms, that is to say different line combinations, as a function of the respective chrominance signals. In the case of conventional comb signals, the CVBS signal is split into the luminance signal and a chrominance signal which is still to be demodulated into the two color difference signals. In this case, the identification of color edges, in particular, is not always carried out in a manner free from errors. This can lead to only incomplete separation of the luminance and chrominance signals, so that cross effects cannot fully be avoided.

Abstract: A 2-line YC separation device comprising a delay circuit for delaying a composite input video signal for a horizontal scanning period; a first band-pass filter which receives the composite input video signal; a second band-pass filter which receives the output signal of the delay circuit; a Y-correlation detector which receives the output signal of the band-pass filter; a C-correlation detector which receives the output signal of the band-pass filter; a difference detector for detecting a Y signal differential value; a YL-correlation detector for detecting a Y signal correlation; and an AND circuit for logically ANDing the output signals of the YL-correlation detector and the Y-correlation detector.

Abstract: A 2-line YC separation device reduces the number of delay circuits used for horizontal scanning time delay and minimizing arithmetic operation errors of comb-line filters.

Abstract: In a video display terminal (VDT) adapter connected to a moving picture output device, inputting means inputs, from the moving picture output device, an input moving picture signal indicative of input moving pictures having brightness which changes drastically. Connected to the inputting means, picture temporal frequency attenuator means selectively attenuates a particular frequency band of the input moving picture signal to produce a smoothly-changing moving picture signal indicative of smoothly-changing moving pictures. The particular frequency band includes human sensitive frequency components. Connected to the picture temporal frequency attenuator means, outputting means outputs the smoothly-changing moving picture signal as an output moving picture signal. The particular frequency band may lie on a range not less than 7 Hz.

Abstract: A comb filter arrangement comprising at least one delay circuit and an adder, this adder being twice supplied with a video signal modulated on a carrier, which video signals are applied mutually shifted with time. The signals are delayed by the delay circuits, so that either video signal applied to the adder is delayed relative to the other video signal by a given period of time. Furthermore, the delay circuits are arranged in switched capacitor technique.

Abstract: A system for processing both a composite video television (TV) signal and a video cassette recorder (VCR) playback signal containing a combined line noise canceller and comb filter sharing a single delay line and a 3.58 MHz oscillator that drives a quadrature demodulator for demodulating both playback chrominance signals extracted from the playback signal and television chrominance signals extracted from the television signal. The system also provides automatic gain control to both the composite video TV signal and the VCR playback signal.

Abstract: For activating or deactivating the comb filter function with pixel precision, a comb filter arrangement including a delay circuit (3) and a first matching circuit (1) having at least two storage cells, these circuits receive a picture signal, having a sequence of individual pixels applied to the comb filter arrangement. The output signals of the delay circuit and the first matching circuit are superposed by a superposition stage (4) supplying a filtered picture signal from its output. The matching circuit (1) is implemented in such a way that it gives the picture signal applied thereto substantially the same amplitude variations as the delay circuit (3), and that the difference between the delay of the output signals from the delay circuit (3) and the matching circuit (1) corresponds to a nominal value.

Abstract: A circuit for separating composite video signals into luminance and chrominance signals in response to motion of a displayed image. A motion detecting section detects motion of an image to be displayed on a television screen according to input composite video signals in order to generate motion sensing signals corresponding to motion of the image. A first comb-filtering section adaptively comb-filters input composite video signals in a vertical direction according correlation among three continuous horizontal scanning lines to separate input composite video signals into first comb-filtered chrominance signals and first comb-filtered luminance signals. A second comb-filtering section adaptively comb-filters input composite video signals in the time direction in response to a correlation between frames in order to separate the input composite video signals into the second comb-filtered chrominance signals and the second comb-filtered luminance signals.

Abstract: A comb filter for use in a video decoder is described. The comb filter includes a line memory for storing as successive pairs of U and V samples of a decoded video signal corresponding to a previous horizontal line of video information and a line memory for storing a second previous horizontal line of video information. The filter also includes a circuit to calculate an average value of both U and V from a previous sample and a corresponding sample from a previous line. The filter also includes a circuit for calculating a correction term for each one of the averages. The correction term is calculated from the opposite color component as was used to calculate the average value.

Abstract: A luminance and chrominance signal separating apparatus includes an A/D converter for A/D converting an input composite color television signal by a frequency of eight times of a color subcarrier frequency; a decimation filter for converting the A/D converted digital video signal into a signal with a frequency of four times of the color subcarrier frequency; a chrominance signal separating circuit for extracting a chrominance signal from the signal which was thinned-out by the frequency of four times of the color subcarrier frequency; an interpolating filter for converting the separated chrominance signal into a signal with a frequency of eight times the color subcarrier frequency and outputting a chrominance signal; a delay device for delaying the A/D converted digital video signal by a delay time which occurs when the A/D converted digital video signal passes through the decimation filter, the chrominance signal separator and the interpolating filter; and a subtracting circuit for subtracting the chrominanc

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 technique for effectively separating luminance and color signals from a composite video signal in an NTSC-type television system sampled at 4 times the color subcarrier frequency in an NTSC type picture processing system includes steps for (1) delaying the composite video signal through a plurality of line and sample delay elements and then generating a plurality of sample signals; (2) detecting the correlations between a predetermined reference sample signal and the sample signals in the neighborhood which are in phase with the predetermined reference sample signal and then delaying the composite video signal; (3) determining any direction in which the luminance and color signals are separated and filtered; (4) separating and filtering the luminance and color signals from the composite video signal in the determined direction or in a plurality of predetermined directions; (5) detecting the vertical and horizontal correlation of sample signals which are out of phase with the reference sample signal and are

Abstract: A luminance signal/color signal separator circuit having an input terminal and luminance and color output terminals includes a comb filter connected between the input terminal and the color output terminal; an amplitude detector having an input connected to the color output terminal; a filter having a first input connected to the input terminal and a second input connected to an output of the amplitude detector; and a combiner having an output connected to the luminance output terminal, a first input connected to the input terminal and a second input connected to an output of the filter. The separator circuit processes a composite signal which includes an original luminance signal and an original color signal. The filter passes a gain controlled color band signal.

Abstract: A digital filter (20,30) separates an M-bit (12) chrominance component (C12) from an N-bit (8) digital composite video signal (CV) supplied thereto, M (12) being greater than N (8) due to arithmetic operations (24,44,46,50) required for the separation. The separated M bit chrominance component is reduced to N-bits and subtracted from the composite video signal to provide a separated luminance component. For bit reduction, the separated chrominance component (C12) is subjected to symmetrical rounding (100A or 100B and 104) and limiting (104). Advantageously, symmetrical rounding of the chrominance component provides reduces a tendency for the luminance component to exhibit contouring when displayed.

Abstract: A system for transmitting and receiving digital data which utilizes pre-coding at a transmitter, and selects post-coding at a receiver when co-channel interference not present or post-comb processing at the receiver when co-channel interference is present. The system includes a symbol interleaver at the transmitter and a symbol deinterleaver at the receiver which minimizes the byte errors by organizing the data input at the pre-coder at the transmitter such that the symbol errors and their respective propagated errors are re-organized so as to be disposed adjacent to each other, thereby forming adjacent symbol errors. The effect of this re-organization is to increase the probability that each pair of adjacent symbol errors correspond to bits which lie in the same byte.

Abstract: A decoder using an adaptive non-separable digital filter has a correlation control circuit that generates from a composite video signal a set of filter coefficients for the non-separable digital filter. The filter coefficients are a function of a correlation angle for the image represented by the composite video signal. The non-separable digital filter, using the set of filter coefficients determined by the correlation angle, separates the composite video signal into its luminance and chrominance components. The non-separable digital filter may be approximated by a set of discrete filters having a common input, with each output being multiplied by a correlation factor, the correlation factors being the filter coefficients. The resulting multiplicands are summed to produce the separated luminance and chrominance components.

Abstract: A two-dimensional adaptation type luminance/chrominance signal separation apparatus for separating the luminance signal from the chrominance signal in accordance with correlation in a vertical direction includes a coefficient generator for generating a selection signal and mixing coefficients according to correlation of composite video signals, a chrominance signal processor for selectively outputting the chrominance signals filtered from the composite video signals according to the coefficients generated from the coefficient generator whereas the chrominance signals are generated by mixing respective chrominance signal filtered through a predetermined region, and a luminance signal generator for detecting a chrominance signal generated from the chrominance signal processor and a luminance signal generated from the composite video signal.

Abstract: A vertical impulse detecting circuit 104 detects the difference between a level of data of a present horizontal line of an input composite picture signal and a level of data of each of a horizontal line a plurality of lines ahead and a horizontal line a plurality of lines behind. Either an output signal of a three-line chrominance signal separating circuit 100 or an output signal of a horizontal chrominance signal separating circuit 101 is selected as a chrominance signal (CC) that is supplied to a subtracter 105 according to an output signal of the vertical impulse detecting circuit 104.

Abstract: A filter is used for separating luminance and color signals from a composite color television signal in which the frequency of the color signal is multiplexed over the high-frequency region of the luminance signal. When a picture is detected with respect to its motion under frame correlation and if that motion is relatively small, the separation of luminance and color signals is performed based on the interframe correlation. If the motion is relatively large, the separation of luminance and color signals is made based on the interfield correlation. The luminance and color signal separation based on the interfield correlation is attained from a correlation with signals in a field spaced forwardly away from the subject field by one field. This is accomplished by selecting a calculation having the highest correlation in calculations for an objective sample point and a plurality of sample points located about the objective sample point.

Abstract: A method of determining a chrominance element for pixel signals of an optical image for a 1H delay circuit. The pixel signal(s) are first filtered through a band-pass filter to remove low frequency luminance components and a part of the filtered signal is fed through a 1H scan line delay. The result is a OH pixel signal and a 1H pixel signal one scan line apart. The OH pixel signal is added to the 1H pixel signal to generate a combed chrominance component, and the OH pixel signal and the combed chrominance component are compared to see which is the greater. If the value of the OH pixel signal is greater or equal to the combed chrominance component, the combed chrominance component is output as the chrominance element. If the value of the OH pixel signal is less than the combed chrominance component, the OH pixel signal is output as the chrominance element.

Abstract: An apparatus and a method for separating luminance and color signals from an input video signal.

Abstract: A decoder that provides simultaneous horizontal scanning lines for digital color video, and then band splits each line into high and low frequency signals using low pass filters and subtractors to subtract the low frequency signals from the source video. The high and low frequency signals and the source video for each line is fed to a three tap comb filter, and the high and low frequency signal inputs to the comb filter are also fed to a vertical transition detector that demodulates the high frequency signals, and then provides differences between pairs of lines for luma, chroma magnitude, and chroma phase. The difference signals are used to provide a control signal that automatically switches the comb filter from a three line weighted comb to a two line comb when large vertical transitions are detected in luma, chroma magnitude, or chroma phase.

Abstract: For realizing more accurately a signal separation of a luminance signal and a chrominance signal, a signal separation automatic adjusting circuit in a YC separation comb filter includes an amplitude adjusting loop for detecting a level of a color signal component remaining in the separated luminance signal to adjust amplitudes in an image signal and a 1H delayed image signal, a first phase adjusting loop for adjusting phases of the image signal and the 1H delayed image signal which are respectively inputted into an adder, and a second phase adjusting loop for adjusting phases of the image signal and the 1H delayed image signal in the manner of suppressing the color signal remaining in the luminance signal. According to the constitution, it is possible to prevent an intermix of the color signal component into the luminance, thereby obtaining the YC separation automatic adjusting circuit having a high accuracy.

Abstract: A circuit that separates a luminance signal and a color signal so that dot interference in a color transition area of a reproduced image is minimized. A color video signal is transmitted to an adaptive bandpass filter via a vertical carrier color signal extraction filter. An output signal from the adaptive bandpass filter represents the color signal portion of the color video signal. The color signal is subtracted from the color video signal via a subtractor circuit to produce the luminance signal portion of the color video signal. Since the output signal of the bandpass filter is subtracted from the color video signal, the luminance signal portion of the color video signal is separated without being affected by different colors before and after a color transition point.

Abstract: A composite video input signal is combined with a noise reduction signal to form a noise reduced first video signal which is delayed by multiple time periods of (i) one line less one-half color cycle, (ii) one line and (iii) one line plus one-half color cycle to form respective ones of first, second and third time delayed signals. The first and third delayed signals are combined to form an averaged signal from which a subtractor subtracts the composite video input signal. The resultant difference signal is limited to form the noise reduction signal. The noise reduced first video signal and the second delayed video signal are combined in an output circuit to provide noise reduced and separated chrominance and luminance output signals.

Abstract: A luminance and chrominance signal separating apparatus includes a first delay device for delaying an input chrominance color television signal by one horizontal period and a second delay device for delaying a reference signal one horizontal period. An output of the first delay device is regarded as a reference signal. Two correlation detectors detect correlations between the reference signal and the signals separated from the reference signal by one horizontal period. A black level detector detects a black level of the reference signal. Filters separate a chrominance signal from the reference signal. A selector selects one of the outputs of the filters based on the output of the correlation detectors and the output of the black level detector. A bandpass filter limits a bandwidth of the selector output and outputting a chrominance signal. A subtracter subtracts the chrominance signal obtained from the bandpass filter from the reference signal and outputs a luminance signal.