Abstract: The invention relates to an architecture making it possible to store and transfer still or moving video images, the said architecture comprising at least one input circuit (E1, E2, . . . , En) allowing access for data intended to make up video images, a memory area (M) making it possible to store video images, at least one video image output circuit (S1, S2, . . . , Sj) and a video bus (B) intended to provide for the transfer of information between the memory area (M), the input circuit and the output circuit, characterized in that the memory area (M) is a general-purpose memory and in that the video bus (B) has a width L greater than or equal to the width of the memory area (M).The general-purpose memory is operated in a centralized manner by a control circuit (CTRL).The invention applies to computer platforms dedicated to the transfer of Broadcast quality images or alternatively to video devices for built-up image animation.

Abstract: The process is characterized in that the pilot signals (10) generated upstream of the device (11) whose non-linearity it is desired to measure pass through a known non-linear device (15) delivering intermodulation products of known characteristics and in that at least one of the known intermodulation products is harnessed in order to modulate, with the aid of synchronous detection circuits (17), at least one of the signals relating to the components of the intermodulation products of the device to be measured.The applications pertain to the analog transmission of television signals over optical fibers.

Abstract: An amplification circuit comprising a device for compensating for its input current. The amplification circuit includes an amplifier and a capacitor located on the input side of the amplifier. The input-current compensation device consists of a current generator, generating a current Ig, a switch and a device for measuring the average current charging or discharging the capacitor during the time that the switch is open. The current Ig is such that: Average current=Ia-Ig, where Ia is the input current of the amplifier. The value of the average current is close to zero. The value of the current Ig which the current generator must output, so as to make the average current close to zero, is calculated using the device for measuring the average current. The invention particularly applies to a circuit for restoring the DC component of a video signal.

Abstract: A device and method that overlays, onto a new colored background a subject clipped from a source video image having a subject moving against a first colored background. A clipping key KD is calculated which makes it possible to separate the color space representing the image into three regions, a first region defining a volume representing the first colored background, a second region defining a volume representing the subject, and a third region representing a region of transition between the first colored background and the subject. A video image VD representing the subject moving against the new colored background formed according to the formula:VD=KD.times.subject video+(1-KD).times.background video,where "subject video" and background video respectively represent a video image containing the subject and the video image of the new colored background.

Abstract: The invention relates to a method for determining a key KD for clipping a subject moving against a colored background, the said key making it possible to separate the color space into three regions, a first region defining a volume representing the colored background, a second region defining a volume representing the subject and a third region defining a transition region between the colored background and the subject, where the device and method defines the volume representing the colored background in the form of a cone of aperture angle .alpha. whose axis of symmetry (W) passes through the achromic and zero-luminance point of the color space and a point representing the color of the colored background. The invention also relates to any type of electronic apparatus implementing the abovementioned device and method, such as video mixers or autonomous devices for clipping and overlaying video images.

Abstract: Frequency modulated signals are demodulated through a limiter circuit that chops the signal to give pulses whose occurrence frequency is proportional to the instant frequency of the received signal. The invention is devoted to a new processing of those pulses. The leading edges of the pulses are time integrated. The obtained signal is then as usual, low pass filtered to give the demodulated signal. The main advantage of this new processing is that the circuit that makes this processing does not implement delay lines and can then be made as a single chips.

Abstract: A device for processing color data (R, G, B) of a signal representing an image. The processing device has a mechanism which, for each color data item, consist of an analog/digital converter (12, 13, 14) and a buffer memory (MT1, MT2, MT3), a circuit (PT) for processing the digital data output by each buffer memory, and serializer circuits (SE1, SE2, SE3) which collect the signals output by the processing circuit (PT) and make it possible to generate signals (D1, D2, D3) intended to reproduce the image with a slow-motion effect. According to an improvement of the invention, the control unit includes a mechanism (MO, SE4) for generating a signal (I) making it possible to reproduce the image at normal speed. The device applies particularly to television studio cameras in the professional sector.

Abstract: In a detector for detecting a frequency-modulated light wave including a PIN photodiode (2), biasing means (11, 12, 15) are introduced which are capable of automatically forward biasing or reverse biasing the PIN photodiode (2) depending on the received light power. The output voltage of a transimpedance preamplifier stage (6) receiving the signal from the PIN photodiode (2) is thus automatically limited to a value below the saturation threshold of this transimpedance preamplifier stage (6).

Abstract: The shifting system comprises a local scrambler (13) on a production site giving the necessary digital data elements to a scrambler (15) shifted to a transmission site. These data elements are inserted, at the image rate, into the compressed television signal transmitted on a low bit rate link to the transmission site. The application relates to systems for the transmission of encrypted television systems.

Abstract: A data compression device having a decorrelation circuit (10), a circuit (12) for quantizing the decorrelated data and a control circuit (13) acting on the quantization step. The device includes is a circuit for calculating a histogram of the decorrelated data and for calculating the quantization step on the basis of this histogram (11) in order to force, in accordance with the coherence of the histogram, this quantization step. The latter is calculated on the basis of the distances between the local maximum values of the histogram.