Abstract: A method and apparatus for encoding a television source signal having a first bandwidth, into a frequency multiplexed signal having a narrower bandwidth and comprising a plurality of subcarriers modulated with digital information. Each of said subcarriers has an amplitude, bandwidth and coding characteristic which reflects the relative importance of the digital information provided thereby. The frequency multiplexed signal is suitable for use in a broadcasting environment wherein a conventional television signal is also used and wherein said subcarriers are disposed in frequency, in positions which are least likely to result in interference to or from said conventional signal. The invention also includes a receiver for decoding the frequency multiplexed signal and for providing a high definition display.

Abstract: A method and apparatus for generating and receiving a high definition television signal suitable for use in a broadcasting environment wherein a conventional television signal is also used, having multiple frequency multiplexed subcarriers placed within the frequency spectrum of the signal so as to minimize interference with and from the conventional television signal.

Abstract: A method and apparatus for digital encoding are described for compressing the augmentation channel signals (chrominance and luminance signals for panel information and high frequency luminance and line difference signal) so that this information can be transmitted in a 3 MHz wide RF channel using a digital transmission scheme such as QPSK. Analog signal components are sampled and converted to digital signals. Each of the signals is fed into a separate coder which reduces the number of bits/pixel required to reconstruct the original signal. Compression is achieved by quantization and removal of redundancy. The compression scheme is based on the use of DCT together with VLC. Each augmentation signal has its own coder, which is adapted to the unique statistics of this signal.

Abstract: A method and apparatus for encoding a television source signal having a first bandwidth, into a frequency multiplexed signal having a narrower bandwidth and comprising a plurality of subcarriers modulated with digital information. Each of said subcarriers has an amplitude, bandwidth and coding characteristic which reflects the relative importance of the digital information provided thereby. The frequency multiplexed signal is suitable for use in a broadcasting environment wherein a conventional television signal is also used and wherein said subcarriers are disposed in frequency, in positions which are least likely to result in interference to or from said conventional signal. The invention also includes a receiver for decoding the frequency multiplexed signal and for providing a high definition display.

Abstract: Each line of a wide aspect ratio television signal is divided into a main panel component and two augmentation panel components for transmission or storage. The two augmentation panels are transmitted in a multiplex analog format on the same channel. They are transmitted adjacent to one another so that additional signals such as audio signals will occupy the same time slots regardless of the respective widths of the panels. (The sum of the panel widths remains constant even in pan and scan operations). Weighted transition augmentation samples effect a transition from the last redundant pixel of one augmentation panel component to the first redundant pixel of the second augmentation panel component.

Abstract: Each line of a wide aspect ratio television signal is divided into a main panel component and an autmentation panel component joined to the main panel component at a stitch point for transmission or storage. At the transmitter, a first signal is extracted from the horizontal line signal, the first signal including the main panel component, a plurality of main panel redundant pixels extending from the main panel into the augmentation panel component, and a multiplicity of weighted main panel transition samples extending further into said augmentation panel component from the redundant samples. Similiarly, a second signal includes the augmentation panel component, a plurality of augmentation panel redundant samples extending into the main panel and a plurality of transition augmentation samples extending from the redundant augmentation samples further into the main panel and weighted to create a predetermined transition curve.

Abstract: A high definition television signal with a sequential scan with the standard number of lines per frame and double the frame frequency is processed to generate a single MAC line having a duration substantially equal to that of four sequential lines of standard duration. Each MAC line has two luminance components having different compression ratios. For the remaining two lines, compressed line difference signals are transmitted, thereby allowing reconstruction of all luminance lines at the receiver. Each MAC line further has a U chrominance component and a V chrominance component, alternatively compressed 1:4 and 1:2. The remaining parts of each MAC line are taken up by data signals and audio as well as the necessary clamping. The luminance and chrominance signals are prefiltered to prevent artifacts. The filtering is geared to the visual characteristics of the human visual system, i.e.

Abstract: A high definition television system to provide an efficient use of bandwidths, derives from a high definition television source signal, composite main signals and composite line differential signals. These signals are divided into main center components and main panel components and line differential center components and line differential panel components. The line differential center components and main center components are then quadrature modulated and transmitted as a vestigial sideband signal over a first transmission path. The main panel components and the line differential panel components are quadrature modulated and formed into a vestigial sideband signal which is then time multiplexed with the high frequency luminance signal forming a time multiplexed signal. The time multiplexed signal is then frequency multiplexed with a digital sound and synchronization signal in order to form an augmentation signal which is transmitted over a portion of a second transmission path.

Abstract: An improved color subcarrier and amplitude reference signal and means for its utilization are provided for color television systems, particularly high definition, wide aspect ratio television systems wherein the high definition signal is decomposed into two signals for transmission via two separate channels and recombined at the receiver to reproduce the original high definition image.

Abstract: A system is described for transmitting two conventional television signals (for example NTSC style 525 line, 2:1 interlaced signals) over a two line MAC (multiple analog component) signal. Both an encoder and a decoder and a method for use in conjunction therewith are described.

Abstract: A method and apparatus for generating a multi-carrier high-definition television (HDTV) signal including a digital sound and sync (DSS) component, on a conventional television channel, for example, 6 Hz. MAC derived signal components are quadrature modulated on a plurality of subcarriers and combined in frequency multiplexed form to create an RF signal.

Abstract: A system for transmitting and receiving a high definition television signal with characteristics which are determined in part at the receiver. The system transmits an AM signal formed by frequency multiplexing a number of components derived using an HDMAC-60 encoder.

Abstract: A system for generating high definition television signals. An augmentation signal is provided for supporting the transmission of additional panel information, increasing the aspect ratio of an NTSC compatible main television signal component. Line differential information, as well as high frequency luminance and high frequency chrominance are transmitted in the augmentation signal super line time interval without frequency interleaving components. The high definition augmentation signal is derived by subsampling the high definition image produced by an HDTV source along the diagonal direction of its two dimensional frequency spectrum. The horizontal frequency bandwidth of the HDTV image is perserved without an objectionable loss of resolution to the human visual system.

Abstract: A high definition television augmentation channel which provides an efficient use of bandwidth, time expands line differential, panel, and luminance signals. The time expanded line differential signals are arranged in time coincidence and quadrature modulated, as are the corresponding segments of the panel signals. The quadrature modulations providing signals in a common frequency band. Luminance signals are converted to the common frequency band and time multiplexing of the three signals is performed. The resulting time multiplexed signal is then frequency multiplexed with the DSS signals which have been frequency converted to occupy a frequency band contiguous with the common frequency band.

Abstract: An adaptive comb filter employs vertical and horizontal edge detectors to selectively activate a vertical high-pass filter and a horizontal band-pass filter during the occurrence of vertical and horizontal edges in a received television signal, for use in the chrominance/luminance separation process. Artifacts such as "hanging dots" and "crawling dots", inherent in prior art comb filter circuits during the occurrence of vertical and horizontal edges in the composite television signal, are greatly reduced in the process.

Abstract: A high definition television encoder which provides an efficient use of bandwidth, segments line differential signals into left panel, center segment, and right panel line differential signals, and time expands the left and right panel line differential, panel, and luminance signals. The time corresponding expanded left and right panel line differential signals are arranged in time coincidence and quadrature modulated, as are the corresponding segments of the panel signals. The quadrature modulations providing signals in contiguous frequency bands. Luminance signals are converted to a band abutting the contiguous frequency bands as are digital stereo audio signals. Center segment line differential signals are time expanded to be consistent with conventional television horizontal line times and quadrature modulated with the television image signals to occupy a frequency band contiguous with the abutting and contiguous frequency bands.

Abstract: A high definition television signal having 525 lines per frame, a sequential scan, and 59.94 frames per second is encoded into a time multiplex signal for transmission. The encoder drops alternate lines, but creates line difference signals which allow reconstruction of the dropped lines at the receiver. The line difference signals are time compressed, while the luminance signals of the alternate, transmitted lines are time expanded. The encoder can accept programs from any one of a plurality of program originators, as long as the frame and line rates are multiples of one another. The time multiplex signal carries luminance and chrominance components in each line, but updates signals such as high frequency luminance, high frequency chrominance and the line difference signals in a predetermined pattern in sequential frames.

Abstract: An improved color subcarrier and amplitude reference signal and means for its utilization are provided for color television systems, particularly high definition, wide aspect ratio television systems wherein the high definition signal is decomposed into two signals for transmission via two separate channels and recombined at the receiver to reproduce the original high definition image.

Abstract: A high definition television encoder which provides an efficient use of bandwidth, segments line differential signals into left panel, center segment, and right panel line differential signals and time expands the left and right panel line differential, panel, and luminance signals. The time corresponding expanded left and right panel line differential signals are arranged in time coincidence and quadrature modulated, as are the corresponding segments of the panel signals. The quadrature modulations providing signals in contiguous frequency bands. Luminance signals are converted to a band abutting the contiguous frequency bands as are digital audio signals. The digital audio signals, quadrature modulated signals and luminance signals are frequency multiplexed within a 3 MHz band.

Abstract: A method and apparatus for introducing a pan and scan feature to a multiple-signal high definition television (HDTV) system, so that a compatible signal received by a standard TV receiver may be a panned version of a wide aspect ratio HDTV signal, and so that high quality recombination of the compatible and augmenting signals by an HDTV receiver is possible. A pan and scan data word representing the relative movement of the compatible portion of the HDTV signal is inserted during the vertical blanking period of each frame of the HDTV signal, for causing panning synchronization between an HDTV transmitter and an HDTV receiver. The pan and scan data word corresponds to the beginning read address of a fixed coefficient memory containing video attenuation coefficients, which determine the degree of signal attenuation, to be applied at each pixel location along an HDTV scan line.