Abstract: In a television signal processing system of the type which encodes an auxiliary carrier modulated with auxiliary image information in line format, which carrier is placed within the spectral band of standard television signal components, and wherein the modulated auxiliary carrier tends to interfere with the standard television signal, the interference is minimized by spatially variably attenuating the auxiliary image information. The attenuation function is selected to apply greater attenuation to the auxiliary image information at the extremities of the lines than toward the center of the lines.

Abstract: Apparatus is disclosed for reducing unwanted jagged diagonal artifacts in a video signal. At an encoder, moving image information is intraframe averaged over a given frequency range, e.g., above 1.5 MHz, while still image information is subjected to a field repeat process over a given frequency range. At a decoder, still image information is subjected to a frame repeat process over the given field repeat frequency range, while moving image information is left unchanged.

Abstract: A video signal processing system includes a signal interpolator associated with time compression/expansion apparatus. The interpolator is preceded by a high frequency peaking network which responds to a variable control signal representative of a desired amount of displayed image sharpness. In a disclosed embodiment the peaking network responds to a control signal which is a function of a distance between image pixels, and a variable signal from a viewer adjustable image sharpness control.

Abstract: In a widescreen signal encoding system for a television-type signal, side panel chrominance information is not subjected to time compression in an overscan region such as a horizontal overscan region containing time compressed low frequency side panel luminance information. Both low and high frequency side panel chrominance information, and high frequency side panel luminance information, modulate an auxiliary subcarrier.

Abstract: An NTSC compatible widescreen EDTV system encodes and decodes a television signal comprising (1) a main, standard format NTSC signal with auxiliary low frequency side panel image information compressed into an overscan region thereof; (2) auxiliary high frequency side panel image information; and (3) auxiliary high frequency horizontal luminance information. At an encoder, components 2 and 3 are intraframe averaged before modulating an alternate subcarrier. Component 1 is intraframe averaged exclusive of the compressed side panel information before being combined with the modulated alternate subcarrier.

Abstract: A system for expanding/compressing a video signal includes a dual-port memory having read and write address inputs and a video signal input. A pixel counter provides a pixel location signal to the write address input of the dual-port memory, and to a programmed memory device (e.g., a PROM) including a look-up table. The memory device is programmed to provide a time expanded/compressed version of the pixel location signal in accordance with a programmed time expansion/compression factor, which is applied to the read address input of the dual-port memory. A time expanded/compressed video signal is developed at the output of the dual-port memory.

Abstract: A widescreen television signal containing center panel information and time compressed side panel information in an overscan region is intraframe processed above a given frequency only with respect to the center panel information. The intraframe processing apparatus includes a signal delay network with first and second 262H delay elements coupled between an input and an output of the delay network. During a first field interval, signals from the delay input and from an intermediate point between the delay elements are subtractively combined to produce a difference term which is coupled to a signal path. During a second field interval, signals from the delay output and from the intermediate point are subtractively combined to produce a difference term which is coupled to the signal path. An intraframe processed output signal is produced by combining the difference terms from the signal path with a signal from the intermediate delay point.

Abstract: A system for transmitting and receiving signals representing a high-definition television (HDTV) image is disclosed. The signals are sent over two conventional 6 MHz NTSC channels. A first signal, the main signal, is developed by encoding circuitry from HDTV source signals to be compatible with existing NTSC receivers in that it produces a display on those receivers which is not significantly distorted. The main signal includes psychophysically hidden video information which may be used by an extended definition receiver to produce a widescreen image having a higher level of detail than a conventional video image. A second signal, the auxiliary signal, is developed at the transmitter by decoding the main signal and subtracting the decoded main signal from the original HDTV source signals. The auxiliary signal, which includes frequency components from 0 Hz to 20 MHz is split into three bands, A (0 Hz-6MHz), B (6 MHz-12 MHz) and C (12 MHz-18 MHz).

Abstract: In a video signal expanding/compressing system including a video signal interpolator, video signals are peaked prior to interpolation. The amount of peaking is controlled in response to a signal representative of the distance between a pixel of an expanded/compressed video signal and a corresponding pixel of an original video signal.

Abstract: A widescreen television signal having left side, right side and center panel information is converted into a signal compatible with a standard television system, such as NTSC. In the compatible signal, center panel information is expanded to occupy the standard display region seen by a viewer, side panel low frequency information is compressed into the horizontal overscan region, and side panel high frequency information modulates an alternative subcarrier other than the chrominance subcarrier.

Abstract: The present application discloses a video signal processing apparatus for minimizing cross-color and cross-luminance interference in a composite video signal. A first filter is coupled to a color difference signal input terminal and generates a signal occupying a first region of a predetermined spatio-temporal frequency space. A second filter is coupled to a brightness signal input terminal and generates a signal occupying a second region of the predetermined spatio-temporal frequency space exclusive of the first region. An encoder forms a composite video signal from the filtered color difference and brightness signals such that they occupy mutually exclusive spatio-temporal frequency spaces. A television receiver for decoding the composite video signal is described which comprises the serial connection of a vertical-temporal filter and a horizontal filter.

Abstract: A memory system for a television receiver is disclosed. The memory system contains an array of addressable memory cells, each row of which can contain one line of sampled video signals. The number of rows in the array is greater than the number of lines in a frame. Apparatus is included in the memory system for simultaneously writing more than one line of samples into the memory, for simultaneously reading more than one line of samples from the memory, or for both. Simultaneous access to multiple lines allows the reading and writing of multiple corresponding lines of samples from both the current and the prior frame. The row addresses that are used to store the lines of samples for a frame are not the same for each frame, rather the lines of each new frame are stored in rows with lesser addresses than the rows used for the prior frame.

Abstract: The storage locations of a memory system map a field of sample points. Apparatus affording parallel access to a plurality of storage locations describing an array of the sample points in an access window, which window can be shifted to any selected region of field of sample points responsive to orthogonal address coordinates of one of the sample points in the array, is described.

Abstract: Graphics for television display which emphasize circles, ellipses, circular or elliptical arcs, and the radii of circles or ellipses are conveniently stored in image memories addressable in polar coordinates. Television images which are to be rotated are conveniently stored in such memories, so the angular coordinate of the image memory addresses can be incremented or decremented to rotate the image with hardware as simple as a single adder. To read image memories addressed in polar coordinates, the Cartesian coordinates descriptive of television raster display are scan-converted to polar coordinates. This scan conversion takes place in real time at video sampling rates. The generation of the angular coordinate of the polar coordinates is facilitated by dividing one Cartesian coordinate by another by differentially combining their logarithms as found from read-only-memory table look-up, then finding an arc tangent from the logarithm of their difference as found from further read-only-memory table look-up.

Abstract: The calculation of r.sup.2 =x.sup.2 +y.sup.2, where x and y are the Cartesian coordinates of a raster-scanned space, is carried forward by accumulation of 2x+1 and 2y+1 terms. A read-only memory can then be used for table look-up of r, the radial coordinate of raster scan in polar coordinates.

Abstract: A television sync signal generator adapted for ready conversion among various television standards includes a memory in which information related to the amplitude of at least one component of a composite sync signal is stored at address locations each corresponding to at least one particular time in each recurrent television frame. A clock signal generator addresses the memory to sequentially read out the information so the sync signal can be reconstructed. For reducing the number of memory addresses required, each memory address contains information relating to the instantaneous resolution or clock rate. A sample rate controller is coupled to the memory for having the instantaneous clock address rate controlled in response to the contents of the memory.

Abstract: A sync generator uses ROMs addressed by counters to synthesize various television sync waveforms. The ROMs can be changed or reprogrammed to generate sync signals for different standards. By dividing the sync signals into four intervals which are selected by paging signals from one counter, a reduction in required ROM capacity is achieved.