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 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 system for transmitting an interlaced source signal, for example 1050 lines, 2:1 interlaced, via a MAC signal, and decoding and receiving same.

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: 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.

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: For a wide aspect ratio display, the main panel component and augmentation panel component at the transmitting end into which the horizontal line signals of hte source were decomposed are reconstituted at the receiving end by joining the previously separated components together at stitch points. In order to decrease the visibility of the stitch points in the reconstituted wide aspect ratio display, the location of the stitch point in each line is varied. The variation may be on a frame-to-frame bais or on aline-to-line basis. The latter is the preferred form, the line-to-line variation being, preferably, a random variation.

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.