System for the transmission of video signals with adaptive code word allocation, and also a transmitter and a receiver suitable for the system

In a system for the transmission of video signals digitized by means of differential pulse code modulation, the constituent signal words are submitted to a variable-length coding operation. A further bit rate reduction is then realized in that the allocation of the code words to the signal words is periodically adapted to the local statistics of the video signal

Television transmission system with differential encoding of transform coefficients

In a television transmission system for digital picture signals each picture is divided into sub-pictures of N x 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

System for the transmission of video signals with adaptive code word allocation, and also a transmitter and a receiver suitable for the system

In a system for the transmission of video signals digitized by means of differential pulse code modulation, the constituent signal words are submitted to a variable-length coding operation. A further bit rate reduction is then realized in that the allocation of the code words to the signal words is periodically adapted to the local statistics of the video signal

Real-time facial feature extraction by cascaded parameter prediction and image optimization

We propose a new fast facial-feature extraction technique for embedded face-recognition applications. A deformable feature model is adopted, of which the parameters are optimized to match with an input face image in two steps. First, we use a cascade of parameter predictors to directly estimate the pose (translation, scale and rotation) parameters of the facial feature. Each predictor is trained using Support Vector Regression, giving more robustness than a linear approach as used by AAM. Second, we use the generic Simplex algorithm to refine the fitting results in a constrained parameter space, in which both the pose and the shape deformation parameters are optimized. Experiments show that both the convergence and the accuracy improve significantly (doubled convergence area compared with AAM). Moreover, the algorithm is computationally efficient

Motion compensator for video coder/decoder

Video encoder and decoder, provided with a motion compensator for motion-compensated video coding or decoding in which a picture is coded or decoded in blocks in alternately horizontal and vertical steps. The motion compensator is provided with addressing means (160) and controlled multiplexers (111-119) for refreshing a search area memory (101-109) at each step, in conformity with the direction of the step

System and method for improving video recorder performance in a search mode

A method and apparatus wherein video images are recorded on a plurality of tracks of a tape such that, for playback in a search mode at a speed, higher than the recording speed the displayed image will consist of a plurality of contiguous parts, some of the parts being read out from tracks each having a different frame recorded thereon

Television system for digital transmission of picture signals

In a television transmission system a digital luminance signal Dy and two digital colour difference signals DCHR(1) and DCHR(2) are applied to a distribution circuit 3 at the transmitter end, which digital colour difference signals are applied thereto possibly after having been subjected to a vertical decimation operation with a decimation factor R. The distribution circuit 3 partitions all these signals into groups of Q samples per group.; After receiving an even number of luminance groups and an even number of chrominance groups, a first half of this number of luminance groups and a first half of this number of chrominance groups is applied to a first auxiliary picture signal output 3(4) of the distribution circuit 3, while simultaneously the other half of the number of luminance groups and the other half of the number of chrominance groups is applied to a second auxiliary picture signal output 3(5) of the distribution circuit. A transformer for performing a forward two-dimensional Q*Q transform is connected to each of these auxiliary picture signal outputs