Abstract: A region from two frames of a television picture is subjected to Fourier transform in processing stages (3 and 4) one via a picture memory (2), and the resulting transforms compared in a comparator (5) whose output is subjected to inverse Fourier transform in a processing stage (6). The output of comparator (5) is also applied to a sample rate modifier (7) in which this output is enlarged prior to being subjected to inverse Fourier transform in a further processing stage (8). The outputs of processing stages (6 and 8) are respectively low and higher correlation functions to one pixel and one-quarter pixel resolution respectively. A given number, say 20, of sample points of greatest magnitude in the low resolution correlation function are selected in a largest vector selector (9) whose coordinates are used in a peak locator (10) which locates the peaks in the higher resolution correlation function associated with the selected samples to produce coordinates for these peaks to quarter pixel accuracy.

Abstract: In a device for spatio-temporal sub-sampling of digital video signals representing a succession of interlaced or sequential images divided into blocks of m.times.n points (m and n being positive integers), the device comprising, in series, a circuit for the spatial prefiltering of the said sequence of fields, which circuit is intended to deliver a succession of sequential images which are limited with respect to the bandwidth, a spatial sub-sampling circuit, and a temporal sub-sampling circuit: a motion estimator which on the basis of, on the one hand, signals corresponding to the even fields and on the other hand, signals corresponding to the odd fields, delivers one or more information items on the motion in an odd field with respect to the which surround it.

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 extended definition television (EDTV) system transmits, receives and displays both EDTV and NTSC signals using a NTSC channel bandwidth. The system procudes an EDTV broadcast signal having a picture with a 16:9 aspect ratio and at least one adjacent horizontal border to produce an overall image apsect ratio of 4:3. Picture information is also selectively modulated onto the horizontal border. The EDTV broadcast signal is transmitted in a NTSC format, and a receiving circuit is provided comprising a display with a 16:9 aspect ratio, a detector for determining whether an EDTV or other type of signal is being received, and an expansion circuit responsive to the detector to produce an expanded picture for display. When an EDTV signal is received, it is expanded and filtered vertically and is expanded horizontally and the 16:9 picture is displayed on the 16:9 display. The receiving circuit derives picture information from both the picture portion and the border portion of the EDTV signal.

Abstract: Video graphics system which, by means of a graphics cursor, permits the identification of encoded surfaces of images represented on a screen. In order to do this, there are added to the parameters of the encoded surface, for each surface, an identifier which can be read by slices in the course of readings effected on a plurality of successive frames. An identification memory permits the accumulation of all the slices until the complete acquisition of the identifier. This situation is brought to the attention of the user.

Abstract: In this system a transmission of certain high definition picture elements is provided such that at the receiving side it is possible to recover a picture of the normal definition without it being necessary to use additional circuits.

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: Television pictures are divided up into a number of regions and corresponding regions for two pictures are correlated to produce motion vectors at an output connectrion (2) of a motion vector generator (1) which also at an output connection (4) produces signals signifying relative magnitude and/or width of the vectors which control the weighting operation of a weighting circuit (3). The weighted vectors are applied to a two-dimensional summing arangement (5) where corresponding vectors from the various regions are summed in individual stores. A largest vector selector (6) selects the most dominant of the motion vectors depending upon the quantities stored in the summing selector (6).

Abstract: An arrangement for estimating motion in a sequence of picture comprising first, second and third picture stores (10, 20, 30) arranged in series to ensure the permanent storage of three respective consecutive pictures denoted, for example, by their rank 2k, 2k+1, 2k+2 in the sequence of pictures, and a recursive displacement estimator (40) receiving the outputs of said first and third picture stores to update at each extension of the classifying tree the displacement vectors relating to the junctions of the tree and the send them to a delayed-decision circuit (50), said delayed-decision circuit receiving said updating information and also the outputs of said picture stores and supplying, for each block preceding the current block of L blocks, the information of the group in which this preceding block and the information of the corresponding displacement vector is finally classified.

Abstract: A receiver for a high definition television signal in which the signal prior to transmission is sub-sampled on a block-by-block basis according to the movement has an input (39) which receives the sub-sampled signal which is applied to a shuffler (40) which shuffles the pixels of blocks in a manner which is the inverse to that performed prior to transmission. The correctly positioned pixels are applied to means (43,44,45) for adaptive switched interpolation filtering capable of providing spatial frequency filter responses which approximate those at the transmitter, for sub-sampling blocks of the interpolated picture are sub-sampled but where pixels adjacent but outside a block are sub-sampled with the same structure as that of the block and for non-adaptive switched interpolation filtering for providing spatial frequency filter responses which substantially correspond to those at the transmitter. An output (46) provides the reproduced high definition television signal.

Abstract: Method of and arrangement for converting the temporal rate of high definition television pictures, in accordance with which, after the division by two of the line period in a line period changing circuit (100) and storing the fields of the picture for a working period corresponding to one period with the aid of field memories (90, 80, 70, 311), these fields are processed in parallel by simple field repetition, by taking a motion compensated half-sum and by filtering and, by the selection of one of the three field sequences thus processed e.g. with the aid of digital assistance signals provided in the HD-MAC high definition television standard. This method and device can be used in high definition television receivers.

Abstract: A method and apparatus for detecting a maximum vertical frequency component in a received interlaced transmission and substituting therefore, a uniform zero vertical frequency component in order to form a sequential scan display without introducing motion induced artifacts.

Abstract: In a predictive encoding circuit the transmission of prediction errors to the predictive decoding circuit is selectively suppressed and prediction errors having a predetermined value are applied to the prediction circuit in both the encoding circuit and in the decoding circuit, instead of the non-transmitted prediction errors. In order to determine which prediction errors are not transmitted, a masking function value is determined for an actual pixel in the encoding circuit. This is a linear combination of weighted difference between two pixel values of a predetermined cluster of pixels located in the vicinity of the actual pixel. The actual prediction error is not transmitted only if, for example this masking function value is within a certain range and the previous prediction error has been transmitted. In the decoding circuit the masking function values are determined, starting from the regained local pixel values.

Abstract: In a television transmission system for digital picture signals each picture is partitioned into sub-pictures of N.sub.1 .times.N.sub.2 pixels for limiting the bit rate. Each sub-picture is subjected to a forward picture transform for generating basic picture weighting factors. To this end each sub-picture is multiplied by a reference picture which has different values for different pixels (for example, as described by a Gauss function). This multiplied sub-picture is subsequently multiplied by a number of kernel pictures so that the said basic picture weighting factors are obtained. Each kernel picture is equal to the product of the reference picture and a basic picture. Of the collection of basic pictures each basic picture is an orthogonal polynomial associated with the square value of the reference picture. For regaining the original sub-pictures each weighting factor is multiplied by the original kernel picture from which the weighting factor is obtained.

Abstract: In a television transmission system for digital picture signals each picture is divided into sub-pictures of N.times.N picture elements for the purpose of limiting the bit rate. Each sub-picture is subjected to a two-dimensional forward transform to determine coefficients. These coefficients are converted into a series of serially occurring coefficients in which the AC coefficients in this series are arranged in such a way that the magnitude variation of these AC coefficients in the series is monotonous. The magnitudes of the AC coefficients thus arranged are subjected to a differential encoding so that the difference between the magnitudes of two successive AC coefficients is transmitted instead of the magnitude of the AC coefficients themselves.

Abstract: A hydrid encoder for video pictures comprising a motion estimator, and an inter-intraframe encoding selector which comprise a common calculation module. Known hybrid encoders for transmitting video pictures comprise a motion estimator and an inter-intraframe encoding selector. Due to the required high processing rate the motion estimator and the inter-intraframe encoding selector must have a parallel processing structure which leads to quite a considerable number of components. To this end a calculation module is proposed which can be used in the motion estimator and in the inter-intraframe encoding selector. Use of this invention, for example in hybrid encoders for video telephone apparatus.

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 picture display device having a display tube and a deflection unit comprising a field deflection coil and a line deflection coil is disclosed. To comply with a predetermined interference radiation standard, the picture display device is provided with one interference suppression coil or with a system of interference suppression coils, which interference supression coil or system of interference suppression coils is oriented and can be energized in such a manner that, measured at a predetermined distance from the picture display device, the strength of the local magnetic dipole field is below a desired standard.

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.