Abstract: A video recorder, includes: a filter for performing a comb-filtering operation and supplying a comb-filtered component of a video signal; controllable influencing apparatus for terminating the output of the comb-filtered component and activating instead, the propagation of the non-filtered component; transition detection apparatus for detecting a vertically extending transition and supplying characteristic information upon detection of such a transition; control information generating apparatus, arranged between the transtion detection apparatus and the influencing apparatus, for generating control information enabling the termination of the output of the comb-filtered component and the activation of the propagation of the non-filtered component for a period of time which is longer than possible by means of the characteristic information.

Abstract: An improved method for generating an NTSC compatible color television video signal having a main carrier signal and a color subcarrier signal 3,579,545 Hz above the main carrier signal. The main carrier signal is modulated by a luminance signal, while the color subcarrier is modulated in quadrature with color difference signals. The luminance and color difference signals provide 525 scan lines of picture frame information at a rate of 29.97 frames per second so that the color subcarrier has 227.5 cycles for each scan line, resulting in 119,437.5 color subcarrier cycles per frame. The additional half cycle causes a subcarrier phase inversion from frame to frame, which produces undesirable dot-crawl. The improvement comprises incrementing the phase of the color subcarrier by a fixed increment at a number of predetermined intervals in each picture frame, to produce a total phase shift which prevents the phase inversion. The total phase shift is an odd-half-multiple of a color subcarrier cycle.

Abstract: A method and device for reducing moiré by preventing the production of the second harmonic of the video signal Nyquist frequency. A nonlinear function is applied to one of a) a digital video signal having a nonlinearity between an electrical video signal and luminance, and b) an analog video signal to create an output signal having a linearity between the electrical signal and luminance. The output signal is displayed on a display having a linearity between the electrical signal and luminance.

Abstract: Frames of a digital video signal are spatially filtered to remove impulse and other noise from the video signal. The spatially filtered frame is temporally filtered to further remove noise from the digital video signal. The spatial filter is adaptive, heavily filtering portions of low detail in the represented subject matter while lightly filtering or not filtering portions of moderate to high detail in the represented subject matter. As a result, clarity and detail in the subject matter of the digital video signal are preserved. The temporal filter is similarly adaptive and determines if and to what degree the subject matter of portions of the spatially filtered frame correlate with corresponding portions of a previous frame. By previously spatially filtering the frame, determinations regarding the correlation of the current frame with corresponding portions of the previous, which is also spatially and temporally filtered, are more accurate.

Abstract: Device and method for correcting a color distortion on a TV receiver, is disclosed, the method including a multi-path channel estimation step wherein a transmission channel existing between a transmitted side in a broadcasting station and a color demodulating circuit in a TV receiver is estimated for obtaining an impulse response using a reference signal transmitted from the broadcasting station for equalizing a multi-path channel, a color subcarrier phase error calculation step wherein a phase error of a color subcarrier between the transmitter side of the broadcasting station and the TV receiver is calculated using the estimated impulse response, and a phase correction of a reproduced color subcarrier step wherein a phase error on the TV receiver in reproduction of a color is corrected as much as the phase error obtained in the color subcarrier phase error calculation step.

Abstract: A circuit for moiré suppression detects the Nyquist frequency in an input video signal. Based on detected alternating structures indicative of the Nyquist frequency, the circuit fades between outputting the input video signal and a low-pass filtered version of the input video signal. When the output signal is applied to a video display, moiré is suppressed.

Abstract: A method is proposed for processing transitional regions in a picture signal. The picture signal comprises a sequence of digital pixel values. A number of adjacent pixel values, which contain a processing pixel value, are combined to form a processing block. A corrected pixel value is calculated for the processing pixel value. The maximum and minimum pixel values are first determined in the processing block to define the transitional region. The transitional region is then split into a number of sections on the basis of the magnitude of pixel value. Finally, a determination is made as to the section in which the processing pixel value is located. The processing pixel value is allocated a corresponding correction value in order to increase, to reduce or to leave unchanged the processing pixel value, in accordance with a predetermined transfer function.

Abstract: A chrominance signal C is separated (30) into component vectors U and V and coupled via respective paths each including a controllable gain amplifier (60,62) to respective outputs (56,58). A chroma overload protection unit (50) is provided including a saturation calculator (78) determines the saturation of the vector components and provides a saturating indicating signal to a gain characteristic unit (72) which jointly controls the gain of the amplifiers to proportionally limit the vector component magnitudes as a given function of the saturation indicating signal on a pixel by pixel basis thereby providing output component vectors (U,V) exhibiting no tint shift upon limiting conditions.

Abstract: An image signal processor generates color difference output signals from color component signals representative of image data. The image signal processor includes multiple color calculators that generate multiple sets of primary color signals from the color component signals. Multiple color difference calculators connected to the color calculators generate multiple sets of color difference signals using the respective sets of primary color signals. A synthesizing circuit combines the multiple sets of color difference signals using a predefined ratio to generate the color difference output signals. By generating multiple sets of signals, errors due to noise can be filtered and higher quality images produced.

Abstract: A luminance notch filter for preventing color crosstalk adaptively attenuates a SECAM luminance signal depending on the strength of the luminance signal using digital filtering techniques. The adaptive luminance notch filter includes a bandpass filter centered at the chrominance band that is operative to receive the input luminance signal and provide a bandpass filtered luminance signal. The bandpass filtered luminance signal is multiplied by a gain factor and the multiplied luminance signal is subtracted from the input luminancee signal to provide a notch filtered luminance signal. A detector coupled to the bandpass filter output detects the signal strength of the bandpass filtered luminance signal and the gain factor is adapted in accordance with the detected signal strength. The bandpass filter comprises an infinite impulse response (IIR) filter that is preferably an all-pole IIR filter of at least 3.sup.rd order.

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 intra-field time division tone display method for dividing the time width in a field of a TV signal into a plurality of subfields in the pixel storing time direction and displaying the TV image by controlling the presence or absence of light emission of the subfields and an apparatus therefor, wherein there are at least two subfields (most significant subfields) whose luminant time widths are longest and almost equal and when it is assumed that the tones are displayed in the ascending order starting from the lowest level of tone in light emission of the subfields, the tone of a TV image signal is displayed under a rule that two or more light emissions are not started from the aforementioned at least two most significant subfields at the same time, accordingly the dynamic false contour noise of a moving image followed by movement of the viewing point can be reduced remarkably and a moving image of high image quality and high quality can be obtained.

Abstract: In a noise reducer whose S/N improving amount is variable, as to such a region where image quality deterioration caused by the noise reducer becomes relatively apparent, and both a luminance level and a chroma level are low, the S/N improving amount thereof is decreased. To the contrary, as to such a picture having a dark high frequency range component and a small movement component, no control is made of the S/N improving amount by the above-described luminance level and chroma level, but the normal S/N improvement is sufficiently carried out.

Abstract: A video signal conversion device of the present includes a flicker reduction section including a plurality of line buffers for storing data in accordance with an address thereof. The flicker reduction section receives non-interlaced signals, converts the non-interlaced signals to interlaced signals and performs a flicker reduction process.

Abstract: A digital color encoder capable of reducing the aperture distortion of D/A conversion and the waveform distortion of the video signal without resulting in the increase of the consumed electric current. At first, digital signals sampled with a sampling frequency are inputted as original color signals. The digital composite color video signals of the sampling frequency fl are created from those signals by digital signal processing with the combination of matrix circuit, color burst controlling circuit, modulation circuit, addition circuit, and synchronization signal adding circuit, etc. Next, the sampling frequency of the composite color video signal is converted by a sampling frequency converting circuit inserted immediately before the D/A converter. The converted signal is further converted to an analog signal capable of being inputted into the TV set by a D/A converter, and the signal is outputted as a video signal.

Abstract: A method and system for reducing the effects of false contouring and reducing color shading artifacts. An image signal 102 is dithered by the addition of a small noise signal from a noise generator 500. The added noise signal breaks up the edges of homogenous blocks of pixels, causing the created image to appear to have a smooth transition from one region to the next. The image dithering is especially useful in digital color image displays where processing performed on the chrominance portion of the image signal often causes quantization errors which lead to sharp transitions between similar shades when the input image included a smooth transition.

Abstract: A current pixel of a video image is adaptively filtered to provide stronger filtering when there is a high likelihood that noise is present. Weaker filtering is provided when the presence of a color and/or brightness edge is likely in the video image. Each pixel has luminance and chrominance amplitude values. In a filtering method, a current pixel is intermediate to first and second pixels in the video frame. Difference signals are determined based on the amplitude difference between the current pixel and first and second adjacent pixels. A plurality of available filters provide successively stronger filtering of the current pixel amplitude. One of the filters is selected for filtering the current pixel according to the difference signals. Secondary difference signals which indicate the amplitude difference between the current pixel and pixels which are adjacent to the first and second pixels are also considered in the selection process.

Abstract: The present invention relates in general to a digital-signal processing apparatus as well as a digital-signal processing method and, in particular, to a jitters removing apparatus as well as a jitters removing method. In the apparatus provided by the present invention, a TV signal received by a tuner or a video signal supplied by a VCR is fed to a moving-average correction circuit and a first FIFO circuit. In a correlation-value computing circuit, correlation between a carrier chrominance signal extracted by the moving-average correction and a carrier chrominance signal delayed by a second FIFO circuit by a predetermined time is found and a correlation value having a maximum absolute value is supplied to a quantization circuit. In the quanitization circuit, the quantization value is quantized to determine a class code. Then, coefficients for taps indicated by the class code are read out from a coefficient ROM unit and supplied to a linear first-order weighed-sum computing circuit.

Abstract: A device for processing video signals includes a noise reduction arrangement and a contour correction arrangement. To improve color correction, a color correction arrangement (11) is arranged between the noise reduction arrangement (10) and the contour correction arrangement (12).

Abstract: A noise reducer to which image data obtained by decoding coding data using a DCT coding is supplied. The noise reduser is comprised as follows. Noise extracting unit for extracting a noise component, first and second noise cancelling unit for cancelling the extracted noise component from input image data, a memory for delaying the image data from the first noise cancelling unit by a predetermined amount and supplying the delayed image data to the noise extracting unit, decimating unit for decimating the image data to be written into the memory, and interpolating unit for interpolating an output of the noise extracting unit and supplying the interpolated output to the second noise cancelling unit whose output is taken out.

Abstract: The object of the present invention is to provide a color noise slice circuit in which the color noise slice process does not cause changes in hue. The color noise slice circuit of the present invention is provided with a divider that receives color-difference signals (R-Y) and (B-Y) and calculates (R-Y)/(B-Y), a memory that stores values for .theta.=tan.sup.-1 ?(R-Y)/(B-Y)!, memories for storing sin .theta. and cos .theta., a noise slice width setting circuit that sets the slice width .DELTA.S, multipliers that calculate .DELTA.Sr=.DELTA.S* sin .theta. and .DELTA.Sb=.DELTA.S * cos .theta., and slice circuits that execute color noise slice processing of color-difference signals (R-Y) and (B-Y) using .DELTA.Sr and .DELTA.Sb, respectively, as color noise slice widths.

Abstract: In a noise reducer whose S/N improving amount is variable, as to such a region where image quality deterioration caused by the noise reducer becomes relatively apparent, and both a luminance level and a chroma level are low, the S/N improving amount thereof is decreased. To the contrary, as to such a picture having a dark high frequency range component and a small movement component, no control is made of the S/N improving amount by the above-described luminance level and chroma level, but the normal S/N improvement is sufficiently carried out.

Abstract: A phase detector provides angular phase error measurements of the color burst component of a video input signal. Burst phase errors exceeding a given angular threshold are detected and the number occurring within a given period of time are counted. From the accumulated count, a noise indicating signal is derived and applied to a video picture processor for controlling a parameter of displayed images.

Abstract: A video signal regenerator in color television comprises two video signal regeneration channels each of which has a video signal front detector (5-7) electrically connected to a driving input of a video holding sampler (1-3), while the third video signal regeneration channel has an input receiving a video signal of a pass-band wider than that of other video signals, which channel being analogous to the other regeneration channels and also comprising a video signal front detector (5-7) electrically connected to the driving input of the video holding sampler (1-3).

Abstract: To avoid color defects in the motion-compensated luminance signal, which defects occur in non-motion-compensative time-interpolation of the color signal, a method includes the steps of generating a second color difference signal from a first color difference signal supplied at a first field repetition frequency by way of field repetition, the second color difference signal having a second field repetition frequency which is doubled with respect to the first field repetition frequency, generating a third, time-averaged color difference signal from the second color difference signal by time-averaging of two consecutive fields, generating a fourth, spatially high-resolution color difference signal by a spatially high-resolution interpolation of two consecutive fields from the second color difference signal, forming a fifth color difference signal to be supplied as a linear combination of the third and the fourth color difference signals by means of coefficients which are complementary with respect to a constant,

Abstract: A channel equalizer for a digital television receiver which filters an input signal to remove a noise component mixed therewith during transmission. The channel equalizer comprises an initial coefficient storage unit for outputting a predetermined coefficient to channel equalizer circuit when a certain channel is firstly selected. The predetermined coefficient is used as an initial filtering value for allowing the channel equalizer circuit to update a filtering coefficient so that it can converge on an optimum value. The stored filtering coefficient is output to the channel equalizer circuit when the firstly selected channel is again selected, so that it can be used as the initial filtering value.

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: An apparatus for cancelling noise and improving details of color components of an image by processing a color component value corresponding to a respective pixel, including a high-frequency component detector for individually detecting a high-frequency color component value contained in the color component value corresponding to the respective pixel, a noise detector for receiving the high-frequency color component value detected by the high-frequency component detector, judging whether a noise component is contained in a corresponding pixel and outputting a first binary signal indicative of a judgement result, a storage unit for outputting a value designated by the detected high-frequency color component value and the first binary signal among detail improved values and noise cancelled values both of which are pre-stored therein, and an adder for individually adding the value output from the storage unit and the corresponding color component value.

Abstract: Luminance data Y(1) (i=1,2, - - - ,n, - - - ) are input one by one to a detecting unit, and luminance correlation information R(i-1,i) denoting a luminance correlation or a luminance non-correlation between the luminance data Y(i) and Y(i-1) are generated. Four pieces of luminance correlation information R(n-1,n) to R(n+2,n+3) are stored in a filter controlling unit. Also, chrominance data C(i) are input one by one to a starting-stage chrominance data generating unit, and starting-stage chrominance data C1(n+2) is generated from the chrominance data C(n+1), C(n+2) and C(n+3) according to the luminance correlation information R(n+1,n+2) and R(n+2,n+3). other starting-stage chrominance data C1(n) and C(n+1) are generated in advance in the same manner. Second-stage chrominance data C2(n+1) is generated from the starting-stage chrominance data C(n), C(n+1) and C(n+2) in a second-stage chrominance data generating unit according to the luminance correlation information R(n,n+1) and R(n+1,n+2).

Abstract: A complex filter apparatus for correcting a complex valued input television signal Y having the real and the imaginary parts Y.sub.r and Y.sub.i to produce a complex filtered output television signal Z having the real and the imaginary parts Z.sub.r and Z.sub.i comprises: three filters having their respective filter coefficients (C.sub.r +C.sub.i), C.sub.i and Cr; a first adder for producing an output of (Y.sub.r +Y.sub.i); a first subtractor for producing an output of (Y.sub.r -Y.sub.i); a second subtractor for producing an output Y.sub.r (C.sub.r +C.sub.i)-(Y.sub.r +Y.sub.i)C.sub.i as the real part Z.sub.r ; and a third subtractor for generating an output Y.sub.r (C.sub.r +C.sub.i)-(Y.sub.r -Y.sub.i)C.sub.r as the imaginary part Z.sub.i.

Abstract: In a television system including a source of an intermediate frequency (IF) signal, which signal includes an IF picture carrier amplitude modulated with video information, synchronous demodulator means responds to the IF signal, for providing an in-phase first output video signal that has both luminance and chrominance components, and for providing a quadrature-phase second output video signal that has a chrominance component but substantially no luminance component. Chroma circuitry is responsive to the quadrature-phase second output video signal for generating first and second color-difference signals.

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: Apparatus are provided for producing a noise-reduced image signal from an input image signal having relatively more noise. The input image signal is divided into a number of block signals. A class code is produced for each of the block signals and used to produce low noise image data which is either output as a pixel or block of the noise-reduced image signal or is used to produce the same.

Abstract: A noise reducing apparatus includes a delay device for delaying a first video signal by one horizontal period. Also included is a first subtracter for subtracting the output of the delay device from an input video signal and a limiter for clipping the output of the first subtracter at a designated level. A variable coefficient-multiplier is also provided for multiplying the output of the limiter by a variable coefficient k where 0<k<1. A second subtracter subtracts the output of the variable coefficient multiplier from the input video signal and an adder adds the output of the first subtracter and the output of the limiter. A coefficient multiplier is also provided for multiplying the output of the adder by a fixed value 0.5. A third subtracter subtracts the output of the coefficient multiplier from the input video signal and a correlation detector provides a signal to control the coefficient value of the variable coefficient multiplier in response to the output of the first subtracter.

Abstract: In a television system including a source of an intermediate frequency (IF) signal, which signal includes an IF picture carrier amplitude modulated with video information, synchronous demodulator means responds to the IF signal, for providing an in-phase first output video signal that has both luminance and chrominance components, and for providing a quadrature-phase second output video signal that has a chrominance component but substantially no luminance component. Chroma circuitry is responsive to the quadrature-phase second output video signal for generating first and second color-difference signals.

Abstract: A field difference signal of a luminance signal is transformed to a plurality of frequency components by the Hadamard transformation, subsequently, nonlinear operation and inverse-transformation are applied to the frequency components and the inverse-transformed field difference signal is subtracted from the luminance signal, and thereby noise in the luminance signal is reduced, on the other hand in respect to a color difference signal, motion of a video image is detected on the basis of the level of at least one of the frequency components; and when the motion of the video image is large and the level of the frequency component is larger than a predetermined value, the level of the field difference signal to be subtracted from the color difference signal is decreased; on the contrary, when the level of the frequency component is the predetermined value and below, the level of the field difference signal to be subtracted from the color difference signal is increased.

Abstract: A complex NTSC interference canceler for eliminating NTSC signal interference from in-phase and quadrature phase received television signals including both a desired HDTV signal and NTSC interference signal. The complex NTSC interference canceler uses a bank of complex recursive notch filters with adjustable center frequencies to isolate the NTSC signal's major components, i.e. the picture carrier signal, the chrominance subcarrier signal and the audio carrier signal. A single complex filter is used to isolate each NTSC interference signal component, with each particular filter's center frequency being adjusted to match the frequency of the particular NTSC interference signal component to be isolated by the filter. Each filter's gain may be either fixed or dynamically adjusted to match the amplitude of the NTSC interference signal component. Once isolated, the interference signal components are subtracted from the in-phase and quadrature phase received television signals.

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: An improved chrominance signal playback system and method for a video cassette recorder are disclosed. A radio frequency of composite video signal detected by a video head is applied to a low-pass filter which filters the composite video signal and outputs a low frequency of chrominance signal. The chrominance signal from the low-pass filter is automatically gain-controlled and is demodulated. The demodulated chrominance signal is applied to a color killer circuit. Also, an envelope detector detects an envelope signal from the chrominance signal from the low-pass filter. In response to the envelope signal, an attenuator attenuates the level of the chrominance signal from the color killer circuit. This results in the suppression of white noise in the chrominance signal. Therefore, the signal-to-noise ratio and the accompanying image quality can be enhanced.

Abstract: A signal from an input terminal (1) is supplied to a video signal processing circuit (2) which derives a carrier chrominance signal. The carrier chrominance signal is supplied through a low-pass filter (3) to an A/D converter circuit (4). A signal converted by the A/D converter circuit (4) is supplied to a bandpass filter (5) which limits the band of the chrominance signal. A signal from the bandpass filter (5) is supplied to a decoder circuit (6) which alternately derives color difference signals (R-Y) and (B-Y). The signal from the decoder circuit (6) is supplied to a decimation filter (7) which effects a decimation. The signal thus decimated is supplied to a multiplexer (8) and thereby generated as 2-bit series data. A signal from the multiplexer (8) is supplied to a CNR (chroma noise reducer) circuit (9). Thus, the number of bits can be reduced without reducing the number of lines of a chroma signal and data gradation.

Abstract: A decoding signal error concealment system for concealing data which are determined as errors during the process of decoding coded image data into signals in a digital VTR system including an error correction decoder, a block data selecting unit a block data decoding unit, an address and control signal generating unit, a line memory unit and a filtering data selecting unit. The system substitutes error data with image data of the preceding frame when reproducing image data which includes error data, thus enabling substitution of image data including chrominance signals, and prevents boundary effects of the substituted image data.

Abstract: An assembler and splitter of a Weston PAL (W-PAL) video signal has filter functions F.sub.1, F.sub.2 at the assembler for the luminance and chrominance components and corresponding functions F.sub.3, F.sub.4 at the splitter. The transfer functions are defined as F.sub.1 =(L.sub.2 +L.sub.1)/2+(L.sub.2 -L.sub.1)z-.sup.1 /2, F.sub.2 =-(H.sub.1 -H.sub.2)/2+(H.sub.1 +H.sub.2)z.sup.-1 /2, F.sub.3 =(L2-L.sub.1)/2+(L.sub.2 +L.sub.1)z.sup.-1 /2, F.sub.4 =(H.sub.1 +H2)/2-(H.sub.1 -H.sub.2)z.sup.-1 /2 and wherein H.sub.1 (f)=L.sub.2 (2fsc-f) and H.sub.2 (f)=L.sub.1 (2fsc-f). Thus the filters are non-sharp cut and are compatible with normal PAL.

Abstract: An adaptively controlled noise reduction device in which an input video signal is supplied to first, second, and third adders and in which an output of the first adder is supplied to the second adder via a memory responsive to a controller whereby the memory provides a controllable delay. An output of the second adder is supplied via a first coefficient multiplication unit having variable attenuation that is controlled by the controller to the first adder as well as via a second coefficient multiplication unit having variable attenuation that is controlled by the controller to the third adder. A change-over switch responsive to the controller outputs either a signal from the third adder or from the memory. Therefore, a signal is output even during the delay period produced by the memory when the signal is delayed between the first and second adders.

Abstract: An NTSC interference canceler for eliminating NTSC signal interference from a HDTV signal uses recursive notch filters with adjustable center frequencies to isolate an NTSC signal's major components, i.e. the picture carrier signal, the chrominance subcarrier signal and the audio carrier signal. A single filter is used to isolate each NTSC interference signal component, with each particular filter's center frequency being adjusted to match the frequency of the particular NTSC interference signal component to be isolated by the filter. Each filter's gain may be either fixed or dynamically adjusted to match the amplitude of the NTSC interference signal component. Once isolated, these interference signal components are subtracted from the received television signal which includes both the NTSC interference signal and the HDTV signal. In this manner, the NTSC interference is removed from the HDTV signal.

Abstract: A color signal processing device for processing a carrier chrominance signal is arranged to produce a first sampling signal by sampling the carrier chrominance signal according to a sampling clock signal synchronized with a reference phase of the carrier chrominance signal and a second sampling signal which is of a sampling phase opposite to that of the first sampling signal and to form baseband signals conforming to a color signal by using the first and second sampling signals. This arrangement enables the device to process the color signal without causing any signal deterioration that tends to result from DC fluctuations of the carrier chrominance signal.

Abstract: A television signal converting apparatus receives a high definition television signal which is processed approximately linearly on the transmission and receiving sides and whose transmission only is processed non-linearly. A non-linear level correction circuit is provided, which collectively simultaneously carries out two kinds of non-linear processes, namely, a transmission inverse gamma correction and a CRT gamma correction, which are executed on the transmission side, thus precisely reproducing the signal level of a luminance signal by using a small-scale circuit.

Abstract: A periodic input signal Sa is input into a first subtracter and is input on the other hand into a second subtracter, a difference signal Sb between the periodic input signal Sa and a signal Se obtained by delaying this signal by 1H is obtained in a second subtracter. This difference signal Sb is input into a first limiter amplifier having a specific gain factor and a second limiter amplifier having a smaller gain factor, the outputs of the first and second limiter amplifiers are input into a third subtracter. A signal Sc is obtained by subtracting the output of the second limiter amplifier from the output of the first limiter amplifier. This signal Sc is subtracted from the input signal Sa by the first subtracter to obtain a filter output Sd.

Abstract: An encoding apparatus and method for encoding color television signals which improves the quality of a display image by selecting the most effective passband of a motion and pattern adaptive 3-D filter according to the shape of a pattern or the still and motion image signals, which prevents mixing of a luminance signal and a chrominance signal at an encoding site to obtain the highest resolution for the display image.

Abstract: Cross color from composite television signals is suppressed by averaging baseband chrominance samples spaced a certain number of frames apart, or when motion is detected in the television signals, by averaging baseband chrominance samples spaced a certain number of lines apart. Cross color suppression when motion is detected may be improved by low-pass filtering the line-spaced chrominance sample average. Both NTSC and PAL implementations are presented.

Abstract: In an FM television signal angle modulated with luminance and chrominance information, there exists a high degree of correlation between picture elements occurring one line period apart. In an effort to steer the pass band of a tunable bandpass filter to the instantaneous frequency of the incoming television signal, a steering signal is developed which utilizes this high degree of correlation. For NTSC systems, luminance information is delayed by one-line period (63.5 us in the U.S.A.) and combined with suitable delayed chrominance information to form the filter's steering signal. For MAC systems, one-line delayed luminance and two-line delayed chrominance information are alternately applied to the filter as its steering signal. By steering the pass band of the filter to the incoming signal, maximum signal will be captured with minimum noise, enhancing the signal-to-noise ratio of a color television system.