Victor Company of Japan, Limited

Shigehiro Ito

Yuji Nishi

Kazuyuki Ebihara

Tatsushi Koguchi

Osamu Tajima

Tatsushi Kouguchi

Kazyuki Ebihara

Tatsushi Kuguchi

A television ghost removal apparatus comprises a transversal filter that receives input television signals, compensates waveform distortion included in the signals, and removes a ghost component; a waveform extractor that extracts signal waveforms of predetermined periods that include reference signals for ghost detection from the television signals; a coefficient setter that compares reference waveform signals and the extracted signal waveforms to obtain error signals, and sets coefficient data corresponding to the error signals, and in accordance with this coefficients data, changes filter coefficient of the transversal filter; a band limiter means for removing unnecessary high-region components included in the coefficient data, and supplying the coefficient data from which the unnecessary high-region components have been removed to the transversal filter means, the unnecessary high-region components being outside a frequency band of the reference signal; and a counter means for counting the number of times that the coefficient data have been generated by the coefficient setting means until the television signals return to a status where ghost has been removed, and for activating the band limiter means when the number of times reaches a predetermined number.

Apparatus for removing ghost from television signals including a

The present invention relates to an improved image improvement apparatus which can be applied to video apparatus and to various other types of image processing apparatus. This invention has as an object the emphasis of the edge directly adding a waveform step difference to a middle position of a waveform change portion of an envelope of color signals in the form where they have been amplitude modulated, and therefore provides an apparatus which prevents unnatural contour compensation, improves color saturation phenomenon without giving an unnatural sensation to the viewer, facilitates the use of digital circuits and for which adjustment of the edge effect is possible. The control signals are obtained by control signal generating circuit and subtracters which use the input signals, output signals of a delay circuit, and output signals of a delay circuit. The output signals of a synthesizer are supplied to a signal selector circuit along with said signals. The signal selector circuit selects and outputs one of the three supplied signals in accordance with a control signal, and obtains an output signal for which the edge has been emphasized. The input signals, and each of the output signals of the delay circuits are supplied to a signal selector circuit. The control signal formation circuit and the subtracters use the signals to obtain the control signals. The signal selector circuit selects and outputs one of the supplied five signals in accordance with the control signal and obtains an output signal for which the edge has been emphasized.

Picture quality improving apparatus for compensating contour of images

Signal components of the luminance signal are delayed by a 90.degree. phase by a first filter and pass therethrough, where the closer the frequencies of the signal components to the upper limit frequency of the frequency bandwidth of the luminance signal, the less the signal components attenuated. The signal components also pass through a second filter, where the phase of the signal components do not change, the closer the frequencies of the signal components to the upper limit frequency of the frequency bandwidth, the less the signal components attenuated. The signal components that have a phase difference of 90.degree. with respect to each other and that pass through each of the filters undergo vector composition to generate a signal that has an amplitude which is the root of the sum of the squares of the two amplitudes. A signal that has the same phase as the signal component that passes through the second filter and that has the same amplitude as the amplitude of the signal subjected to the vector composition is then generated. From this signal the signal component that passes through the second filter is subtracted to generate the edge emphasis component. This edge emphasis component is added to the luminance signal to emphasize the edge of an image.

Image enhancement system

A ghosting cancel apparatus which can reduce the circuit scale through the use of a one-line memory to remove ghosting, comprises an A/D conversion circuit, a timing signal generation circuit, a one-line memory, a field number register, a calculation processing circuit, a transversal filter, and a D/A conversion circuit. The timing signal generation circuit supplies ghost cancel reference (GCR) field numbers to the field number register, write enable signal to the one-line memory, and read enable signals to a microprocessor inside the calculation processing apparatus. When the one-line memory receives write enable signals, and extracts GCR basic signals from the transversal filter to store them. When the microprocessor receives the read enable signals, and stores it in the waveform memory inside the calculation processing apparatus. The microprocessor performs calculation processing for compensation signals as a weighting coefficient for the transversal filter and sets and supplies it and as a result, removes ghosting from image signals.

Apparatus which employs the variable weighing coefficients for a

A waveform distortion removing apparatus includes a digital filter having taps and being controlled in response to tap coefficients. An error signal sequence is generated from a video signal. The error signal sequence contains a waveform distortion. A quadrature signal is generated which has a quadrature relation with the error signal sequence. An absolute value of the quadrature signal is derived. The absolute value of the error signal sequence and the absolute value of the quadrature signal are compared with each other. A greater of the absolute values is selected. The tap coefficients are set in dependence upon the selected greater of the absolute values.

Apparatus for removing waveform distortion from a video signal

A transversal filter filters an input video signal with a variable filtering characteristic. A waveform of a ghost cancel reference signal is periodically extracted from the input signal. An average of the successively-extracted waveforms is calculated. The filtering characteristic is determined on the basis of the calculated average of the extracted waveforms. An extracted waveform which is contaminated by an error or a jitter is rejected and is prevented from being used in the calculation of the average of the extracted waveforms.

Ghost canceler with adaptive transversal filter

Waveform distortion removing apparatus

A television ghost removal apparatus comprises a transversal filter that receives input television signals, compensates waveform distortion included in the signals, and removes a ghost component; a waveform extractor that extracts signal waveforms of predetermined periods that include reference signals for ghost detection from the television signals; a coefficient setter that compares reference waveform signals and the extracted signal waveforms to obtain error signals, and sets coefficient data corresponding to the error signals, and in accordance with this coefficients data, changes filter coefficient of the transversal filter; an S/N measurer that measures signal to a noise ratio (S/N) of the television signals; and an S/N judgment circuit that prohibits change of the filter coefficient by the coefficient setter when the S/N has deteriorated, and that initializes the coefficient data when the S/N has recovered to a favorable status. In addition, there can be provided a band limiter circuit that removes unnecessary high-region components outside a frequency band of the reference waveform signal.

Television signal according to the signal-to-noise ratio of the

An apparatus for removing a ghost component which disturbs a picture signal by means of a ghost canceling reference signal included therein. The reference signal is extracted from the picture signal and judged as to whether it has a specific level in a reference time interval. The extracted reference siganl is also judged as to whether a color burst signal is canceled. If both judgements are positive, a judgement signal is generated which allows the extracted signal to be examined how it is disturbed by the ghost component. In response to the examination, the ghost component is removed from the picture signal.

Apparatus for removing ghost component disturbing picture signal

A ghost cancelling device including a filtering portion made up of a transversal filter for cancelling a ghost component included in input video signals, a waveform extracting circuit for extracting a part, which corresponds to a predetermined period of time and includes a reference signal for cancelling a ghost, of a signal included in the input video signal, a waveform converting circuit for performing the waveform conversion of the signal corresponding to the predetermined of time and extracted from the input video signal, a subtracter for comparing an output of the waveform converting circuit with a preset reference waveform and outputting a signal in accordance with the result of the comparison, a coefficient setting circuit for setting coefficients having values in accordance with the output signal of the subtracter and a waveform checking circuit interposing between the waveform extracting circuit and the waveform converting circuit. The waveform checking circuit decides whether or not the output of the waveform extracting circuit should be sent to the waveform converting circuit. Thus, the ghost cancelling device can interrupt an operation of cancelling a ghost when the input video signal is abnormal and prevent occurrence of a malfunction and a runaway.

Ghost cancelling device with waveform checking circuit

A transversal filter filters an input video signal with a filtering characteristic determined by tap gains. A row of error signals are generated on the basis of a difference between a ghost cancel reference signal in the input video signal and a predetermined reference signal. A magnification setting circuit sets a first magnification in accordance with the row of the error signals. A weight setting circuit converts an output signal from the magnification setting circuit into weighting data and feeding the weighting data into the transversal filter as the tap gains. The weight setting circuit functions to correct the first magnification into a second magnification in accordance with row numbers denoting the respective error signals in the row.

Ghost canceller employing plural reference signals

Ghosts from an input video signal are substantially eliminated by supplying to the signal a filter for deriving an output video signal. A weight setting circuit controls the filter frequency response. A control signal for the weight setting circuit sets the filter frequency response to substantially eliminate the ghosts. The control signal is derived by responding to one of the video signals to derive a first digital signal that extracts a pulse-like signal having a predetermined time period from the video signal. The position in the time axis of a peak of the first signal is detected to generate a signal having a reference waveform at the time corresponding to the detected position in the peak time-base. A second signal having a value representing the magnitude of the relative values of the first signal and reference waveform is derived. A third signal representing a criterion function for the presence of a ghost in the input video signal is derived in response to a unipolarity function of the average value of the value of the second signal. The second and third signals control the value of the control signal for the weight setting circuit.

Ghost cancelling device using variable amplifier controlled by criterion

Ghost canceler using reference signals to generate updated criterion

An optical type disc is recorded with information signals on each sloping surface of a spiral or concentric V-shaped grooves formed on a recording surface thereof, wherein the information signals are recorded as rows of geometrical depressions or projections on each sloping surface of the V-shaped groove and the inclination angle of the bottom surface of the depression or the top surface of the projection is greater than the inclination angle of the sloping surface of the V-shaped groove. An optical type reproducing apparatus reproduces the signals from the disc by relatively scanning the sloping surface of the V-shaped groove by a reproducing spot having a diameter smaller than the width of the V-shaped groove. The reproducing apparatus comprises tracking spot forming system for forming a tracking spot across two mutually adjacent sloping surfaces of the V-shaped grooves at a position deviated with respect to the reproducing spot in a width direction of the V-shaped groove by a distance of 1/4 the width of the V-shaped groove, a photoelectric transducer for independently receiving light reflected from the two mutually adjacent sloping surfaces of the V-shaped grooves, and a moving mechanism for moving an optical system in the width direction of the V-shaped groove responsive to an output of the photoelectric transducer so that the reproducing spot is formed along a predetermined sloping surface of the V-shaped groove.

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Toride, Japan

Shigehiro Ito