摘要:
The motion detection circuit is so constructed that an interframe difference signal is passed through a horizontal direction LPF and a vertical direction LPF in cascade connection, and the interframe difference signal thus obtained is divided by the value obtained by mixing an edge signal of an image and the image level signal of the image by a mixing circuit, thus providing a motion signal.
摘要:
When the receiving system for a band-compression image signal receives a dropout signal representing a dropout portion of an image signal, an output of the third delay circuit of the temporal filter for motion detection processing, that is, motion information of an image signal, which precedes by one field, and a dropout signal activate the signal selection control circuit to produce an output signal for controlling the operation of the signal selection circuit, so that an output signal of the first delay circuit is selected for a static portion of an image, and an output signal of the dropout compensation circuit is selected for a moving portion of an image, so as to effect compensation control of the dropout portion of an image signal, thereby preventing deterioration of the quality of an image.
摘要:
A demodulator for regenerating and demodulating a carrier signal from a four-phase PSK received signal having a data symbol preamble and a fixed phase (one of four phases) of a particular time width using a synchronous detection type demodulating system (remodulation type demodulating system). The demodulator includes an orthogonal demodulating circuit and a remodulating circuit for regenerating a carrier signal which is the data signal during a preamble transmission period from a received modulated signal. The remodulating circuit includes a demodulator having an AFC circuit for detecting a frequency change using a narrow band filter, means for suppressing frequency changes of the four-phase PSK modulated signal received and means for rendering constant the frequency of the regenerated carrier signal passing through the narrow band filter.
摘要:
A high definition color television picture signal is unified by time-axis compressed integration (TCI) and the bandwidth thereof is extremely narrowed by dot-interlace subsampling. As a result, a narrow band transmission picture signal accompanied with a control signal adapted to the restoration of the received original picture signal, which is suitable for satellite broadcast, can be obtained through a comparatively simple arrangement. The received narrow band transmission picture signal can be restored by the interpolation adapted respectively to the stationary picture and the motion picture under control of the control signal or the picture-motional information detected from the received picture signal in combination with the control signal, so that the original high definition can be sufficiently maintained through comparatively simple receiving equipment.
摘要:
In a bandwidth compressed transmission system in which a frequency band of a television signal of 2:1 interlace system is compressed, on an encoder side, by interfield offset subsampling at a first sampling frequency corresponding to a substantially upper limit frequency of the television signal and, after an output signal thus subsampled is applied to a LPF for passing a signal component having an aliased portion resulting from the interfield offset subsampling and having a cut-off frequency substantially equal to one half of the first sampling frequency, by interframe offset subsampling at a second sampling frequency lower than the first sampling frequency and higher than one half of the first sampling, so that a multiplexed subsampled transmission signal which does not include an aliased portion of reverse phase results from the interframe offset subsampling. When decoding, interframe interpolation processing of a multiplexed subsampled transmission signal is performed to obtain a signal for a still picture portion, while intrafield interpolation processing of the same transmission signal is performed to obtain a signal for a motion picture portion. An interframe difference of the transmission signal is detected to obtain a motion detection signal. The signals for still and motion picture are linearly mixed in accordance with the motion detection signal. Motion can be detected completely by utilizing an interframe difference. An arrangement of a receiver can be made simple and improves picture quality.
摘要:
Disclosed is an automatic gain control device which comprises: a first amplitude detection circuit for detecting an average amplitude value of a television video signal, a peak amplitude value of the same television video signal, or a value obtained by mixing the average amplitude value and the peak amplitude value with a predetermined mixing ratio; a second amplitude detection circuit for detecting an amplitude value of a vertical or horizontal synchronizing signal in the television video signal; an amplitude control circuit for controlling an amplitude of an input television video signal; a synchronization circuit for detecting a vertical synchronizing signal and a horizontal synchronizing signal in the television video signal so as to generate various pulses including a clock pulse synchronized with the input television video signal by controlling an oscillation frequency of an oscillation circuit; and a synchronization phase lock detection circuit for detecting whether the synchronization circuit has been pulled into synchronism with the input television video signal, so that the amplitude control circuit is controlled by an output of the second amplitude detection circuit when synchronization phase-lock is established while controlled by an output of the first amplitude detection circuit when the synchronization phase-lock comes out.
摘要:
There is provided an apparatus for compensating a contour of a television signal in a TV signal processing apparatus in which a predetermined control signal including a field interpolation control signal to control an interpolating method when reconstructing by an interpolation an image signal which was band compressed by the sub-Nyquist sampling is time sharingly multiplexed for a blanking period, wherein a signal of a still area processed by a still image system processing circuit and a signal of an animation area processed by an animation image system processing circuit are mixed by a mixing circuit every pixel, when the mixed signal is used as an input signal to the subsequent circuits, the OR of the binary signal of the movement amount and the field interpolation control signal transmitted from the transmission side is calculated, the still and animation areas are distinguished by the OR signal, and a contour is emphasized by a two-dimensional contour compensating circuit for the signal in the animation area.
摘要:
A clamp system for television signal comprises a first clamp device for clamping to a clamp control voltage supplied from an external source by a horizontal clamp pulse and a second clamp device for controlling the DC potential of the television signal by adding the externally-supplied control voltage to an input television signal. The first clamp device is used during the period requiring an early clamp start, and the second clamp device is operated under normal conditions.
摘要:
A television video signal control system is disclosed in which an amplitude control signal and a clamp voltage control signal digitally detected in the automatic gain control and clamp voltage control of a television signal receiver respectively are applied alternately to a single D/A converter. The resulting analog signal is sampled and held alternately at holding circuits corresponding to the two control signals. A D/A converter for converting the two control signals from digital to analog state is thus saved as compared with the prior art.