Abstract: Normally, speed control is carried out by police using radar and camera. The speed of a car can also be recorded in a tachograph. According to the invention car speed is controlled and/or limited using driver-specific smart-cards and millimeter wave communications. When a car (13) enters the sector of a new transmitter (11), its card reader receives a signal telling the reader to consider the time information (t.sub.1) received from the transmitter as a starting time. When the car exits this first sector and penetrates the perimeter of a second transmitter (12), the reader receives over the air a second time information (t.sub.2) and other information (v.sub.1, d.sub.1) from which the speed is calculated and recorded within the card reader. The police can check the recorded information by inserting a special card into the reader.

Abstract: In a method of reproducing a television picture composed of picture points represented by digital signals, the picture points are grouped into blocks which are separated by block edges. The blocks are one of at least two types of blocks, picture point values for points in one type of block are calculated using one set of rules and picture point values for another type of block are calculated using another set of rules. Values for picture points within the block edges are obtained by combining the values obtained for the respective blocks.

Abstract: A method and apparatus for the improvement of the resolution of digital signals. In digital TV signals which are transformed into a frequency domain, irregularities in the pattern of the reproduced video signals occur because of rounding off errors, when the number of bits per sample is reduced during calculation of the coefficients. This is remedied by increasing the coefficients of the transformed signal values following at least one first coefficient, for example a DC-coefficient, and reducing them again after inverse transformation. This is applicable to digital systems using block processing in which, because of a limited amount of bits, a rounding off of the transmitted spectral coefficients is performed in the calculation.

Abstract: A method and apparatus for the improvement of the resolution of digital signals. In digital TV signals which are transformed into a selected frequency range, irregularities in the pattern of the reproduced video signals occur because of rounding off errors, when the number of places is reduced during calculation of the coefficients. This is remedied by increasing the coefficients of the transformed signal values following at least one first coefficient, for example a uniform component, and reducing them again before inverse transformation. This invention can be employed in digital systems using block processing in which, because of a limited number of bits, a rounding off of the transmitted spectral coefficients is performed in the calculation.

Abstract: A circuit for the transformation of digital video signals, which circuit includes components operative for effecting transformation of a digital video signal in the form of a matrix of signal elements in a sequence which processes the matrix signal elements row by row and column by column, respectively.

Abstract: A method for the transmission of a video signal, in which the analogue signal is converted into a digital signal and is digitally transmitted. However, before the transmission is transformed into the spectral domain, some portions of the digital signals are variously weighted on the basis of the physiological behavior of the eye. This weighting is performed by coding the signals to be transmitted in their representational accuracy.

Abstract: Method of correcting television signals transmitted in blocks, including detecting defective blocks with an error detection circuit and calculating substitute information for a block determined to be defective from an environment of the defective block or from a television signal preceding in time the signal containing the defective block.

Abstract: A method and circuitry for correcting discreet values transmitted in blocks. Circuitry performs at least one multiplication as of matrixes to obtain at least one product value having a plurality of digits, while limiting the number of digits. The correction value is then added to the product value. In the preferred embodiment, multiplication is of matrixes representing blocks of chromaticity or gray values by a transformation matrix and the multiplication produces matrixes in the frequency region. In this embodiment, only a single correction value is calculated, which is added to the mean value element of the matrix obtained by the multiplication and which corresponds to a multiple of the arithmetic mean of all of the elements of the image region matrix.