Abstract: The metrological device, for example for a broadcasting network, for monitoring an upline broadcast signal includes a main component and upline control data. The metrological device includes an extraction circuit for extracting the upline control data from the upline broadcast signal and delivering an upline instruction, and a measuring circuit for measuring a parameter of the upline broadcast signal according to the upline instruction and delivering a measurement result. A control circuit produces a downline instruction from the measurement results and an upline result produced by the extraction circuit from the upline control data, and an insertion circuit produces a downline signal to broadcast comprising firstly the main component of the upline broadcast signal and secondly the downline control data containing the downline instruction.

Abstract: A method of measuring the degradations in a digitized image, which are introduced during the encoding of the image is provided. The method consists in: retrieving the block decomposition of the image used during the encoding thereof; offsetting the coding grid in relation to the image such as to define an analysis block decomposition of the image, whereby each analysis block covers a boundary between two adjacent blocks; applying a transform calculation to the pixel data of the image which is encoded using the offset coding grid; extracting the transformed coefficients obtained for each analysis block, coefficients which are likely to be affected by a block effect; applying an inverse transform calculation to the extracted transformed coefficients in order to determine the pixel data of each analysis block; and, for each analysis block, calculating a degradation indicator and, subsequently, the degradation of the image from the degradation indicators for each analysis block.

Abstract: The invention relates to a method of synchronizing first and second digital signals presenting digital elements to be put into correspondence, on the basis of time references. The method includes preliminary synchronization of the two digital signals using time references, by putting time references recognized as having the same value in the first and second digital signals into correspondence; and fine synchronization on the basis of a characteristic parameter obtained from the binary streams of the digital elements, and computed for each of the first and second digital signals.

Abstract: The invention provides a method of evaluating the quality of an audiovisual sequence by: a) training, comprising allocating a subjective score NSi to each of N0 training sequences Si (where i=1, 2, . . . , N0) presenting degradations identified by a training vector MO1 which is given to each sequence Si in application of a first vectorizing method, in order to build up a database of N0 training vectors MOi with subjective scores NS1; b) classifying the N0 training vectors MOi into k classes of scores as a function of the subjective scores NS1 that have been allocated to them, so as to form k training sets EA (where j=1, 2, . . . , k) which have k significant training scores NSRj allocated thereto; c) for each audiovisual sequence to be evaluated, generating a vector MO using said first vectorization method; and d) allocating to the audiovisual sequence for evaluation the significant training score NSRj that corresponds to the closest training set EAj.

Abstract: A method of measuring the degradations in a digitized image, which are introduced during the encoding of the image is provided. The method consists in: retrieving the block decomposition of the image used during the encoding thereof; offsetting the coding grid in relation to the image such as to define an analysis block decomposition of the image, whereby each analysis block covers a boundary between two adjacent blocks; applying a transform calculation to the pixel data of the image which is encoded using the offset coding grid; extracting the transformed coefficients obtained for each analysis block, coefficients which are likely to be affected by a block effect; applying an inverse transform calculation to the extracted transformed coefficients in order to determine the pixel data of each analysis block; and, for each analysis block, calculating a degradation indicator and, subsequently, the degradation of the image from the degradation indicators for each analysis block.

Abstract: The invention concerns a method for synchronising a video image (IM) spatial position to find the position of an initial digital coding grid (GI), by said image (IM) coding blocks, characterised in that it consists in the following steps: a) moving along the direction of the image (IM) lines and/or along the direction perpendicular to the image (IM) lines, an analysis grid (GA) consisting of coding blocks and corresponding to at least part of the image (IM); b) determining for each position of the analysis grid (GA), the transformed coefficients Fu,v of each block of the analysis grid (GA), using a discrete cosine transform (TCD); and computing for each analysis grid (GA) position, an activity parameter (AM, ES) representing the image activity; c) determining the analysis grid (GA) position for which said activity parameter (AM, ES) has a minimal value.

Abstract: The invention concerns a metrological device (200) for monitoring an upline broadcast signal comprising a main component and upline control data. The metrological device (200) includes an extraction circuit (220) for extracting the upline control data from the upline broadcast signal and delivering an upline instruction, and a measuring circuit (230) for measuring a parameter of the upline broadcast signal according to the upline instruction and delivering a measurement result. In accordance with the invention, the metrological device (200) also includes: a control circuit (250) for producing a downline instruction from the measurement results and an upline result produced by the extraction circuit (220) from the upline control data, an insertion circuit (240) for producing a downline signal to broadcast comprising firstly the main component of the upline broadcast signal and secondly the downline control data containing the downline instruction.

Abstract: The invention concerns a method for assessing the degradation of a video image coded by blocks of picture elements or pixels, comprising the following steps: a) selecting an input image and determining its spatial activity (SA) in an analysis window according to the following sub-steps: i) determining for each block (n, m) the transformed coefficients Fn m (i, y) by a block transform; ii) determining from the transformed coefficients Fn, m (i, y) each block spatial activity bsa; iii) determining the analysis window global spatial activity SA1; b) selecting the output image corresponding to the input image and determining said global spatial activity SA2 of the output image; c) comparing the spatial activities (SA2) and (SA1)

Abstract: The invention relates to a method of synchronizing first and second digital signals presenting digital elements to be put into correspondence, on the basis of time references.

Abstract: The invention relates to a method of controlling equipment for monitoring the quality of digital television signals comprising a data stream organized into frames. It comprises the following steps: a) selecting a reference time signal (PCR) in the data stream; b) on the basis of the reference time signal (PCR), generating a multibit digital clock signal (MTS) whose phase is servo-controlled from said reference time signal (PCR) and whose count is deduced unambiguously from the count of a time base (STC) generated during initial encoding of the digital television signals; and c) transmitting at least meaningful bits of the digital clock signal (MTS) to the measurement equipment synchronously with an analog video frame synchronizing signal (STV) as decoded from the data stream so as to generate a measurement triggering signal (MSTC).

Abstract: The invention concerns a method and a system for assessing the quality of a broadcast digital signal. A reference signal (sref) is generated (1001) from an initial signal (so) and jointly broadcast (1002) with a digital signal (sn). At reception level, the broadcast digital signal and reference signal received (snr, sref) are synchronized (2001) and a value D of the distance between the reference signal and the digital signal (snr, sref) is computed (2002) for assigning (2003) a quality value Q. The invention is applicable to the broadcast of audio and/or video digital signals.

Abstract: The invention relates to a method and to a system for measuring the quality of digital television signals comprising a data stream, the method including measuring quality and producing measurement signals that are representative of quality. The method comprises the following steps: a) selecting a reference time signal (PCR) from the data stream; b) generating a multibit digital clock signal (STC′) from the reference time signal, the phase of the clock signal being locked on the basis of the reference time signal (PCR) and its count being deduced unambiguously from the count of an initial time base (STC); and c) labelling the measurement signals with at least some of the bits (HDT) of the digital clock signal that are meaningful given the nature of the measurements performed.