Abstract: The present invention relates to a method of measuring video quality. Said method comprises a step of determining (21) at least one reference level (JND) above which visual artifacts become noticeable to a group of subjects, with a corresponding predetermined artifact metric (M), from a set of reference sequences (RS) of digital pictures only comprising a corresponding artifact. The method of measuring video quality also comprises a step of measuring (22) at least one artifact level (L) of the input sequence (IS) with the corresponding predetermined artifact metric (M). It further comprises a step of computing (23) a video quality metric (OQM) of the input sequence from at least one ratio of the artifact level (L) to the reference level (JND) corresponding to a same predetermined artifact metric. Such a method of measuring video quality provides an objective quality metric.

Abstract: The present invention relates to a method and system for transmitting digital data within an analog TV signal. Digital data are received from a data source. The digital data are then multilevel encoded and a plurality of data symbols in dependence thereupon is provided. Each of the plurality of data symbols is modulated in frequency domain onto a carrier of a plurality of carriers such that each carrier carries a different data symbol. The modulation step is based on an OFDM method and is performed using a serial to parallel converter. After modulation a digital data signal is provided. Some carriers of the plurality of carriers are turned off in the modulation process in order to shape the spectrum of the digital data signal such that the spectrum of the digital data signal comprises notches at locations coinciding with locations of spectral components in the vestigial sideband of the video carrier of the analog TV signal.

Abstract: In the case where an output signal of an image pickup device is compressed and is transmitted through a transmission path with band limitation, when a conventional compression and expansion technique is directly applied, there is a lot of waste and a circuit scale becomes large, so that the cost of the system is raised. In an image processing system or a camera system of the invention in which an output signal of an image pickup device is compressed and is transmitted, the output signal of the image pickup device is made to pass through a luminance signal forming portion and a contour correcting signal forming portion, so that the signal is divided into a luminance signal and a contour correcting signal. These signals are separately compressed by compression processing portions, and multiplexed by a multiplexing portion, and then transmitted through a transmission path with band limitation such as a USB.

Abstract: A wavelet domain filtering technique is disclosed that removes or at least minimizes checkerboard-like noise artifacts that result from capturing a composite NTSC video signal. A Haar basis filter bank is used to obtain a two-level wavelet decomposition. Low-pass filtering is performed on the high-high (HH) and the high-low (HL) bands of the wavelet decomposition since the checkerboard-like noise artifact is primarily visible on the vertical and the diagonal edges of the captured composite NTSC video frame.

Abstract: A system for transmitting digital programming includes a program source providing digital information, circuitry for modulating the digital information onto a visual carrier modulated with analog television programming, and a visual transmitter coupled to the modulating circuitry. Using a phase modulation method, the system phase modulates the digital information onto a visual carrier, reduces the baseband frequencies of the phase modulated visual carrier, and amplitude modulates the phase-modulated video carrier onto a video signal. The amplified and encoded video signal are combined with an amplified sound signal and transmitted. Using an additive method, the system modulates the sidebands of the video carrier with the digital information and amplitude modulates the video signal onto the video carrier. The data-modulated sidebands are phase-shifted such that they will be in quadrature with the amplitude-modulated video signal.

Abstract: A system supplies a compressed digital signal to a digital television receiver and includes a source of compressed baseband signal. An encoder encodes the baseband signal in a digital format, and the baseband signal has a frequency. The frequency of the encoded baseband signal is shifted by a first frequency shifter. A first interpolator interpolates an output of the first frequency shifter, a second interpolator that interpolates an output of the first interpolator, and a third interpolator that interpolates an output of the second interpolator. A second frequency shifter shifts a frequency of an output of the third interpolator to produce a signal at a selected channel.

Abstract: Briefly, in accordance with one embodiment of the invention, a method of reducing flicker in a video image sequence includes the following. Successive video images are temporally filtered. The filter length is adjusted so as to reduce the amount of filtering across temporal discontinuities in the video image sequence. Briefly, in accordance with another embodiment of the invention, a method of reducing flicker in a video image sequence includes the following. Successive video images are temporally filtered. The filter length is dynamically adjusted.

Abstract: In a receiver for receiving digital television (DTV) signals with carriers near the upper frequency boundaries of TV broadcasting channels, co-channel interfering NTSC video carrier and its lower frequency sidebands are removed from intermediate-frequency signal by trap filtering, preferably in SAW filtering used in the intermediate-frequency amplifier. Co-channel interfering NTSC chroma burst and lower frequency chroma sidebands also are removed from intermediate-frequency signal by trap filtering. Artifacts of co-channel interfering NTSC audio signal in baseband DTV signal recovered by in-phase synchrodyne circuitry are cancelled using Hilbert-transformed artifacts of co-channel interfering NTSC audio signal recovered by quadrature-phase synchrodyne circuitry.

Abstract: A signal processing system and process for digitally filtering a single tone digital signal is disclosed. The system includes a single tone signal generator, which may or may not perform frequency modulation. The single tone signal generator receives an input signal and generates a frequency indicator which is used internally by the single tone signal generator and is also communicated to a direct realization filter. The direct realization filter uses the frequency indicator to generate a phase offset indicator, which is communicated back to the single tone signal generator. The single tone signal generator uses the frequency indicator and the phase offset indicator to generate a phase-adjusted single tone signal. The direct realization filter generates a filter gain and multiplies the single tone signal with the filter gain to produce a filtered single tone signal.

Abstract: A method of filtering noise from digital pictures includes selecting a first set of pixels including the union of a pixel of the current picture to be filtered and a second set of pixels temporally and spatially near the pixel. A certain number of extended sums of values assumed by as many pre-established weight functions of the intensity of a selected video component on the first set of pixels is also calculated. The second set of pixels may belong to the current picture or to a preceding picture. Several noise filters for digital pictures are also provided.

Abstract: A digital signal processing vestigial-sideband television modulator receives a television signal. The present invention digitizes the television signal to generate a video signal and a digital processor processes the video signal to generate a complex baseband signal. The complex baseband signal is converted into an in-phase baseband signal and a quadrature baseband signal and modulated to respectively generate a modulated in-phase baseband signal and a modulated quadrature baseband signal. The modulated in-phase baseband signal and the modulated quadrature baseband signal are combined to produce a vestigial radio frequency television signal. The undesired sideband of the vestigial radio frequency television signal is tapped, filtered, and, subsequently, the power level of the undesired sideband is detected. Any imbalance in the modulation process is compensated by using the detected power level of the undesired sideband.

Abstract: Image signals used in a camera from a CCD are sampled-and-held by a CDS circuit, subjected to an A/D conversion, stored in a DRAM, and stored in a recording medium after a compression process of data from an effective area and an optical black area of the CCD by a compressing/decompressing circuit. Image output is regenerating by decompressing the compressed data in the recording medium. A margin area is defined at a boundary area of the effective area and the OB area and the output from the margin area is not used for image data processing, so that noise does not affect the image output. In this camera, high quality image signals can be obtained and a black level can be accurately corrected.

Abstract: A digital radio frequency transmitter system having an input circuit for receiving digital signals to be amplified and transmitted. A digital-to-analog converter converts the digital signals into analog signals. A series circuit is provided including a radio frequency filter and a radio frequency amplifier located downstream from the converter and wherein the filter and the amplifier respectively introduce linear and non-linear distortions into the analog signals for transmission by the transmitter. A digital pre-correction circuit is located upstream from the digital-to-analog converter for pre-correcting the digital signals in a manner to compensate for at least some of the distortions. An analog pre-correction circuit is interposed between the digital-to-analog converter and the series circuit for pre-correcting the analog signals to additionally compensate for at least some of the distortions prior to application to the series circuit.

Abstract: A system and a method for avoiding unwanted objects e.g. a microphone in a field of vision wherein a search field and an alarm field defined in the filed of vision is used to detect the object. Detectable means is attached to the unwanted object so as to make detection of the object easier. A suspension for microphones comprising an internal microphone holder interconnected to a plurality of bars by means of elastic members. A wind hood for a microphone comprising at least an outer, a middle and an inner layer of wind absorbing material stretchable arranged with interspaces around the microphone.

Abstract: An encoder-modulator for coupling a digital baseband television signal to a VSB digital television receiver that includes filters, equalization circuitry, and forward error correction circuitry for correcting signal impairments that are below a given threshold. The encoder-modulator processes the baseband signal for low power transmission on an RF channel with less-than-nominal bandpass characteristics. A coaxial cable or other low noise communication link directly connects the RF signal to the RF input of the television receiver. Any errors or signal impairments in the transmitted signal that are below the predetermined threshold are corrected by the filters and equalization circuitry built into the VSB digital television receiver.

Abstract: An amplifier system including a vacuum tube amplifier having an input signal terminal and an output signal terminal, wherein the vacuum tube amplifier is for amplifying an input signal supplied to the input signal terminal, a phase comparator having a first input terminal responsive to the input signal and having a second input terminal coupled to the output signal terminal of the vacuum tube amplifier, and a phase shifter having a first input terminal responsive to the input signal, a second input terminal coupled to an output terminal of the phase comparator, and an output terminal coupled to the input signal terminal of the vacuum tube amplifier.

Abstract: A transmission system (14) broadcasts a signal. Within the system (14), a power amplifier (20) causes non-linear distortion. A pre-amp component, such as a band-pass filter (32), causes linear distortion. A high power filter (38) is located downstream of the power amplifier (20) and causes linear distortion. A linear equalizer (42) compensates for the distortion caused by the high power filter (38). A non-linear corrector (44) compensates for the distortion caused by the power amplifier (20), and is located downstream of the linear equalizer (42). A linear equalizer (46) compensates for the distortion caused by the pre-amp components (e.g., 32). The compensating components (42-46) are located upstream of the distorting, pre-amp component (e.g., 32). Signal sampling points (70-74) are located downstream of each distorting component (20, 32, and 38). Sampling selectively occurs at one of the sample points (70-74) for use to update compensation.

Abstract: A signal distortion compensating apparatus and method in a digital TV translator are provided that extract a reference signal from a modulator output of a digital TV translator, and conduct a pre-correction based on the extracted reference signal to compensate for a signal distortion involved in the digital TV translator. The compensating apparatus can include a modulator that modulates an input signal while conducting a distortion pre-correction controlled by a control signal applied thereto on the input signal. The modulator outputs baseband signals divided from the input signal. A signal processing unit processes the signals outputted from the modulator, and transmits the resultant signal to subscribers. An auto correction unit compares the signal, which is outputted in a distorted state from the signal processing unit, with a reference signal derived from the baseband signals output by the modulator, and generates the control signal based on the result of the comparison.

Abstract: The invention relates to a communication system 1, wherein the communication system 1 comprises a cable transmission network 3 with several terminal connecting points 6 provided with high-frequency transmission and/or receiving means. The cable transmission network 3 furthermore comprises signal processing means for processing high-frequency signals that can be transported via the cable transmission network 3. The signal processing means comprise prevention means for at least partially preventing the generation of intermodulation products in the signal processing means. The prevention means comprise a pre-connected filter, such as a high-pass LC filter, for stopping voltage peaks through reflection of the energy contained in the energy peaks.

Abstract: A composite analog video signal can be preconditioned by a preconditioning device that removes noise from the composite analog video signal. The preconditioning device can comprise a low-pass filter that removes noise from the composite analog video signal by passing frequencies of the composite analog video signal below about 6 MHz. A decoder can amplify the preconditioned composite analog video signal and can decode the amplified signal into digital component signals. A compression module can encode the digital component signals for transmission over a communication network. The compression module can encode to the digital component signals using an MPEG-1 or other compression standard.

Abstract: A transmission system (14) broadcasts a signal. Within the system (14), a power amplifier (20) causes non-linear distortion. A pre-amp component, such as a band-pass filter (32), causes linear distortion. A high power filter (38) is located downstream of the power amplifier (20) and causes linear distortion. A linear equalizer (42) compensates for the distortion caused by the high power filter (38). A non-linear corrector (44) compensates for the distortion caused by the power amplifier (20), and is located downstream of the linear equalizer (42). A linear equalizer (46) compensates for the distortion caused by the pre-amp components (e.g., 32). The compensating components (42-46) are located upstream of the distorting, pre-amp component (e.g., 32). A interpolation component (22) is located between the three compensating components (42-46) and the distortion causing components (20, 32, and 38) to increase a rate of the signal, such that the compensation occurs at a lower rate of the signal.

Abstract: In a system for receiving a signal containing digital data representing HDTV image information in the form of multilevel symbols formatted into groups of successive fields, each field comprising a field segment, a plurality of data segments, and associated sync components, the received signal is demodulated to produce a demodulated signal. The demodulated signal is comb-filtered to reject NTSC co-channel interference to produce a filtered signal. The filtered signal is trellis decoded with a trellis decoder employing a truncated non-Euclidean metric.

Abstract: A system for transmitting digital programming includes a program source providing digital information, circuitry for modulating the digital information onto a visual carrier modulated with analog television programming, and a visual transmitter coupled to the modulating circuitry. Using a phase modulation method, the system phase modulates the digital information onto a visual carrier, reduces the baseband frequencies of the phase modulated visual carrier, and amplitude modulates the phase-modulated video carrier onto a video signal. The amplified and encoded video signal are combined with an amplified sound signal and transmitted. Using an additive method, the system modulates the sidebands of the video carrier with the digital information and amplitude modulates the video signal onto the video carrier. The data-modulated sidebands are phase-shifted such that they will be in quadrature with the amplitude-modulated video signal.

Abstract: A control signal (k_lum) derived from the luminance component (Y) of a video signal is used to adaptively control a temporal noise reduction filter (10) according to the level of motion in a video image. To compress the control signal for storage in a memory (30), the control signal is averaged over each 2×2 pixel area, and then a non-linear compression function is applied. The non-linear compression function preferably selects quantization values of the control signal which correspond to a perceptually substantially linear response in the noise reduction factor (NRF) of the noise filter (10).

Abstract: Briefly, in accordance with one embodiment of the invention, a method of reducing flicker in a video image sequence includes the following. Successive video images are temporally filtered. The filter length is adjusted so as to reduce the amount of filtering across temporal discontinuities in the video image sequence. Briefly, in accordance with another embodiment of the invention, a method of reducing flicker in a video image sequence includes the following. Successive video images are temporally filtered. The filter length is dynamically adjusted.

Abstract: A system and method for predistorting a signal which is to be amplified by a non-linear amplifier. The system and method uses additional predistortion circuits to eliminate the predistortion caused by amplifier input circuits and amplifier output circuits. In one aspect of the invention, the system and method uses a frequency response and phase corrector circuit to modify the amplitude versus frequency of the signal independent of phase.

Abstract: A waveform analysis unit divides digital data of a video signal stored in a Y memory and a C memory into small blocks, and conducts average value separation and normalization on each of the small blocks. A 1/f fluctuation measuring unit first derives a self-correlation function for each of the normalized small blocks, folds back the self-correlation function to the negative side, and conducts correction processing for making an average self-correlation function over a predetermined section equal to 0. Subsequently, the 1/f fluctuation measuring unit conducts Fourier transform on the corrected self-correlation function, derives a power spectrum, and conducts straight line approximation of the power spectrum. The 1/f fluctuation measuring unit then derives a fluctuation value of the power spectrum from the approximate straight line.

Abstract: A circuit and method for adaptive precorrection of first signals applied to RF signal combiners of a broadcast signal transmitter provides a sample of the combined signal output of the RF combiner and a sample of a second signal to a hybrid so as to cancel from the combined signal the second signal, and to apply the resulting signal sample representing the first signal to an adaptive precorrector which precorrects the first signal before it is applied to the RF combiner. The circuit and method can be used with a two signal combiner, or with a multiple signal combiner.

Abstract: A filter that filters in the spatial and temporal domain in a single step with filtering coefficients that can be varied depending upon the complexity of the video and the motion between the adjacent frames comprises: a IIR filter, a threshold unit, and a coefficient register. The IIR filter and threshold unit are coupled to receive video data. The IIR filter is also coupled to the coefficient register and the threshold unit. The IIR filter receives coefficients, a, from the coefficient register and uses them to filter the video data received. The IIR filter filters the data in the vertical, horizontal and temporal dimensions in a single step. The filtered data output by the IIR filter is sent to the threshold unit. The threshold unit compares the absolute value of the difference between the filtered data and the raw video data to a threshold value from the coefficient register, and then outputs either the raw video data or the filtered data.

Abstract: A transmission system (14) broadcasts an information signal. Within the system (14), several components (e.g., 20-24) cause distortion to the information signal as the signal is processed and proceeds toward a broadcast antenna. Specifically, the group of distortion causing components (20-24) is identified as a first group, and is arranged in a sequence along a signal path (12) toward the antenna. The first group of components (20-24) performs various functions, including amplification, but each subjects the information signal to distortion shifts away from intended values. A second group of components (e.g., 28-32) modifies the information signal to compensate for the distortion shifts imposed by the first group of components (20-24). The second group of components (28-32) is located upstream of the first group of components (20-24).

Abstract: A system and method for transmitting advanced television signals such as digital television signals. The system and method controls the frequency of the RF signal by compensating for errors in the signal received from a transport system. The system and method also reduces the complexity of the transmission system by inserting a pilot frequency signal after the television signal has been filtered and shaped.

Abstract: Interference and/or nonlinear distortions are reduced in a signal communicated from a transmitter to a receiver. To reduce interference, the transmitter is momentarily disrupted, during which time the receiver analyzes interference on the communication path to determine the frequency of at least one peak thereof. Information is communicated from the receiver to the transmitter identifying the frequencies of the interference peaks. Based on this information, the transmitter pre-distorts the signal to accentuate the signal magnitude at the identified frequencies. The pre-distorted signal is then communicated to the receiver, where it is filtered to attenuate the signal magnitude at the identified frequencies. An adaptive scheme periodically determines the interference peak frequencies. For nonlinear distortion cancellation (e.g., CSO/CTB), there is no need to disrupt the transmitter since the frequencies of the distortion are already known.

Abstract: A method and apparatus for generating blocks of data for an image is described. An image is divided into a localized area. For each localized area, pixels are assigned to blocks following a complementary pattern. The complementary pattern is designed such that most pixels are adjacent to pixels arising from other blocks. The neighboring pixels provide information that is useful for reconstructing data that is lost due to burst error. In one embodiment, this is used in the transmission of video signals over a potentially lossy communications channel.

Abstract: Training signal for channel equalization is located in the initial data segment of each DTV data field or in the nineteenth scan line of each NTSC field. The training signal comprises a pseudo-random noise sequence near the conclusion of the initial data segment of each DTV data field or the nineteenth scan line of each NTSC field and an earlier pseudo-random noise sequence. The later pseudo-random noise sequence is used in a television receiver for detecting pre-ghosts and the earlier pseudo-random noise sequence is used in a television receiver for detecting post-ghosts.

Abstract: An adaptive apparatus (10) for compensating a linear distorting action to an information signal within a non-ideal transmission system (12). Within the system (12), an information signal proceeds to a transmitter (34) that has an amplifier (62). A sample signal is coupled-off from the transmitter (34). The linear distorting action of the system (12) includes shifting of at least one aspect of the signal away from its intended value. A linear pre-equalizer (54), located along a signal stream of the information signal to the transmitter (34), pre-equalizes the information signal. An adaptive equalization determination (70), connected to receive the sample signal and the information signal outside of the signal stream to the transmitter (34), determines an amount of pre-equalization required from the linear pre-equalizer (54) to compensate the linear distorting action of the system (12).

Abstract: A digital video encoder for a digital video system wherein digital video data output from an MPEG decoder is input and an analogue composite video baseband signal (CVBS) is output comprises first selection means for selectively outputting first and second clocks in response to a first selection signal, signal dividing means for dividing the input digital video data into a luminance signal and a chrominance signal in response to the output of the first selection means, luminance signal processing means for regulating the gain and offset of the luminance signal, adding a synchronizing signal to the regulated luminance signal, and filtering a low band component of the luminance signal to output the filtered signal as a digital luminance signal, chrominance signal processing means for regulating the gain of the chrominance signal, interpolating the gain-regulated chrominance signal, producing color difference signals, interpolating the produced color difference signals, filtering a low band component of the inter

Abstract: A system and method for controlling the frequency of a signal being transmitted wherein the frequency of the signal received at the transmitter site is error corrected before being broadcast. The error in the frequency may be developed and applied to the intermediate frequency upconversion and/or the channel upconversion to reduce or eliminate the effects of the error. In the system and method, a pilot frequency signal can be added to the signal to be broadcast after the signal to be broadcast has been shaped and filtered.

Abstract: An apparatus and method for determining co-channel interference in a DTV system is disclosed including a first comb filter filtering the received digital data including a data field signal; a pattern generating unit generating a reference sync signal from the data field signal; a second comb filter filtering the reference sync signal; a selection unit receiving either the digital data that passed or have not passed the first comb filter to output one of the data in response to a selection signal; a determination unit determining the presence of a co-channel interference; a first counting unit counting up/down a counted value in response to an output signal of the determination unit; and a second counting unit counting the reliability of the counted value output from the first counting unit, and providing the selection signal to the selection unit.

Abstract: An ATV receiver is provided with a 16-state trellis decoder to achieve improved performance in the presence of NTSC co-channel interference. In one embodiment, the ATV receiver comprises a tuner, a comb filter, and a trellis decoder. The tuner is configured to downmix a selected channel frequency signal to an intermediate frequency signal, where the comb filter is configurable to screen out most of the NTSC co-channel interference. The intermediate frequency receive signal is modified by the comb filter to resemble a partial response signal. The trellis decoder the demodulates the partial response signal in an improved fashion taking into account the state of the trellis encoder and the partial response channel. The trellis decoder may have a 16 state trellis comprised of four 4-state butterflies wherein each edge in the trellis is a single transition.

Abstract: An N-level digitally encoded signal at a symbol rate fs substantially equal to three times the NTSC color subcarrier frequency, N being a plural integer, modulates a carrier signal of a frequency within a few hundred kilocycles of the NTSC audio carrier, for transmission through a channel subject at times to the presence of a co-channel NTSC analog television signal. The modulation is suppressed-carrier amplitude-modulation generating first and second amplitude-modulation sidebands. Any portion of the amplitude-modulation sidebands extending outside the channel is suppressed in the transmitted signal, thereby making the first amplitude-modulation sideband a vestigial sideband providing an image for only a portion of the second amplitude-modulation sideband closer in frequency to the carrier signal.

Abstract: Apparatus and method are provided by which television signals may be transmitted from adjacent NTSC and DTV channels. The NTSC television signals for a first channel are selected from a frequency band including a plurality of channels and wherein this first channel includes NTSC aural and NTSC visual signals. A source of DTV television signals are selected for a second channel in the same frequency band and wherein the second channel is adjacent the first channel. The NTSC visual signal and the DTV signal are combined to provide an intermediate combined signal. The intermediate combined signal and the NTSC aural signal are then combined to provide a combined output signal for application to antenna means for transmitting television signals.

Abstract: A binary shape encoding apparatus encodes a binary alpha block (BAB) consisting of M.times.N binary pixels, M and N each being a positive even integer. The apparatus samples every other horizontal lines of the BAB to generate a first block starting from either a first or a second horizontal line of the BAB and then samples every other vertical lines of the first block to generate a first sample block as a base layer also starting from either a first or a second vertical line of the first block, wherein the first horizontal and vertical lines are the topmost horizontal and the leftmost vertical lines in the BAB and the first block, respectively. Then, the apparatus encodes the first sample block to thereby produce coded base layer data and performs enhancement layer encoding based on the BAB, the first block and the first sample block to thereby provide coded horizontal and vertical enhancement layer data.

Abstract: A system for filtering digital television signals is provided. The system comprises a generator for providing a first data sequence to a private data packetizer, and a transmitter for transmitting the packetized first data sequence in a data channel of a digital television signal. The system further includes a receiver for receiving the digital television signal and recovering the first data sequence. The receiver includes a channel estimator for providing an estimate of channel characteristics, such as estimated channel impulse estimate and estimated noise variance. The receiver further includes an adaptive equalizer filter having an input for receiving the digital television signal and an input for receiving adaptive filter coefficients. The receiver further includes a coefficient processor for calculating adaptive filter coefficients based on the channel estimate, and providing the adaptive filter coefficients to the adaptive equalizer filter.

Abstract: A system encodes an input video signal by subjecting the input video signal to noise reduction to obtain a noise-reduced signal, and encoding a difference between the noise-reduced signal and a prediction signal to produce an encoded signal. The system then decodes the encoded signal to obtain the prediction signal. In the system, the noise-reduction step comprises arithmetically combining the input video signal with the prediction signal.

Abstract: A video encoding method and apparatus is shown wherein image information is represented as a plurality of pixels, the pixels are organized into blocks, pixels transposition is performed on image information at the boundaries of the blocks, the blocks are transform coded and quantized. Pixel transposition involves transposition of alternate pixels at the boundaries of blocks with pixels of neighboring blocks found in a pre-determined direction. The pre-determined direction may be fixed by a system or may be applied on an image by image basis. In the event that the pre-determined direction is not established by a system, a pixel transposition circuit includes a transposition keyword in the output bit stream which is used by a decoded to determine the direction of pixel transposition.

Abstract: Motion vectors and associated errors which are determined in the course of encoding a video signal are used to determine whether respective macroblocks of two or more frames represent the same subject matter albeit displaced by motion represented by the frames. The motion vector errors are compared to a predetermined motion threshold. If a particular motion vector error is less than the motion threshold, the macroblocks corresponding to the motion vector error are determined to represent substantially identical subject matter and the corresponding motion vector represents displacement of the subject matter between the frames due to motion of the subject matter. Accordingly, differences between the macroblocks corresponding to the motion vector error are determined to be due primarily to noise and not to differences in the subject. Therefore, a relatively heavy temporal filter is applied between the macroblocks.

Abstract: At the transmitter side, carrier waves are modulated according to an input signal for producing relevant signal points in a signal space diagram. The input signal is divided into, two, first and second, data streams. The signal points are divided into signal point groups to which data of the first data stream are assigned. Also, data of the second data stream are assigned to the signal points of each signal point group. A difference in the transmission error rate between first and second data streams is developed by shifting the signal points to other positions in the space diagram. At the receiver side, the first and/or second data streams can be reconstructed from a received signal. In TV broadcast service, a TV signal is divided by a transmitter into, low and high, frequency band components which are designated as a first and a second data stream respectively.

Abstract: A trellis-coded modulation (TCM) decoder of a high-definition television (HDTV) receiver is disclosed for use in US-type terrestrial broadcasting, as is a corresponding decoding method. The TCM decoder optionally uses a NTSC-reject comb filter to remove the interference from a co-channel NTSC-type signal. When the input HDTV signal has been passed through the NTSC rejection filter, an 8-state decoding mode is appropriate and a segment sync suspension unit is used to directly connect the data before and after a twelve symbol segment sync. When the input HDTV signal has not been passed through the NTSC rejection filter, an 4-state decoding mode is appropriate and the input HDTV signal is passed unchanged (i.e., without use of the segment sync suspension unit). A field delay directly connects the data of the data segment just before the field sync segment to the data of the data segment just after the field sync segment.

Abstract: A partial response Trellis decoder that performs Trellis coded modulation in a high definition television (HDTV) having a specific and detailed configuration and includes a distance mapper for calculating first, second, third and fourth Euclidean distances between the input signal and a reference value; a Viterbi decoder for Viterbi decoding the first, second, third and fourth Euclidean distances calculated by the distance mapper; a first delay for delaying and outputting the Yiterbi decoded data for each Euclidean distance; a ruler selector for selecting a ruler type signal based on the signals output by the first delay; and a slicer for slicing the selected ruler type signal and the input signal.

Abstract: A television signal transmission signal comprises a suppressed carrier, VSB signal having respective Nyquist slopes at the lower and upper edges of a 6 MHz television channel, the center frequency of the Nyquist slope at the lower edge of the channel being substantially coincident with the frequency of the suppressed carrier, and a pilot signal in quadrature relation with the suppressed carrier. The suppressed carrier is modulated by an N-level digitally encoded signal having a sample rate fs substantially equal to three times the NTSC color subcarrier frequency, with the frequency of the color subcarrier being less than the co-channel NTSC picture carrier by an amount equal to about fs/12. The received signal is demodulated by a synchronous detector in response to the received pilot signal and interfering NTSC beat components are attenuated by a linear filter having notches at fs/12, 5fs/12 and fs/2.