Showing papers in "Signal Processing in 1987"

TL;DR: The vector median filter (VMF) as discussed by the authors is an extension of the MF, which outputs for each window location a number of data elements, and is obtained as a VMF special case by adjusting the VMF parameters.

TL;DR: This Wiener-based displacement estimation algorithm provides a linear least-squares estimate of the update using N observations to obtain a reliable displacement estimate, and has proven to be very successful to compensate motion in some typical video conferencing scenes.

TL;DR: In this paper, spherically invariant random processes (SIRPs) are used as stationary models for speech signals in telephone channels and a comprehensive mathematical treatment is achieved by means of Meijer's G -functions.

TL;DR: A new fast FIR filtering algorithm based on a divide-and-conquer approach that does not require the use of overlap techniques as is usual in the approaches based on cyclic or aperiodic convolutions is established.

TL;DR: In this article, the modulation type is determined when monitoring unknown radio transmissions and automatic recognition procedures based on time-domain parameters additional to the standard envelope and instantaneous frequency are proposed and results of initial simulations reported.

TL;DR: In this paper, the authors compare two methods for the identification of time-varying AR-processes and propose an extension of the second method for the detection of abrupt changes in ARprocesses.

TL;DR: In this paper, the authors show that the group property is not always necessary, even for sampling at points distributed with minimum possible density, and demonstrate that this group property may not always be necessary.

TL;DR: This work investigates the effect on accuracy and the resulting reduction in computational cost of two techniques: an assumption of zero feature correlations, and a method of automatic selection of feature sub-sets, and the consequent dependence of the classification accuracy on the size of the training set.

TL;DR: It is shown in the particular case of TV processing that the resulting effects of a block operation on small nonoverlapping blocks are very similar to the classical DSP operations based on convolutional and Fourier concepts.

TL;DR: In this article, the phase interpolation method for the estimation of the frequency of a tone in noise is generalised to allow frequency estimation of more than one tone over a bandwidth which can be chosen independently of the integration time.

TL;DR: Two models of texture are considered: a multivariate autoregressive (AR) model (vector model) and a 2-D AR nonsymmetric half-plane model, which are used to filter artificially textured test images, as well as naturally textured X-ray pictures of paintings from the Louvre Museum.

TL;DR: In this article, an expert system for geophysical interpretation of seismic reflection data is presented. But it is not shown how to perform a knowledge-based automated interpretation of the reflection data.

TL;DR: A new structural approach for shape recognition in a multiresolution environment is illustrated, which can be divided into several steps: in the first a local classification of the instances of the detected contour is performed, considering a fixed number of paradigm patterns.

TL;DR: In this paper, an analysis of LMS-driven adaptive filters based on stochastic stability theory is presented, and an expression for an upper bound to the residual mean square error is derived.

TL;DR: A more ‘direct’ and numerically robust computation approach of the ladder update recursions using the most recently introduced algebraic method of generalized residual energies (GRE's) is presented, and a VLSI ladder chip-set is proposed.

TL;DR: This paper addresses the pixle labeling problem under the assumption that contextual information in the picture is encoded in the transition probabilities of a second-order Markov mesh random field and shows that the problem can be solved by a linear algorithm generalizing Devijver's F-G-H algorithm.

TL;DR: In this paper, the authors proposed the Predictor Median Hybrid (PMH) filter, which uses forward and backward prediction to estimate the current signal value and the output of the overall filter is the median of predicted values and the actual signal value.

TL;DR: In this paper, the use of polynomial interpolation to approximate a function specified by samples taken at random moments satisfying a Poisson distribution with uniform mean sampling rate was studied.

TL;DR: The same structure can be used for computing the antilogarithm of a number, thus allowing to obtain the quotient of two binary numbers in O(logN) time complexity and O(N2) area complexity.

TL;DR: In this paper, the authors use local statistical properties of residual sequences, jumps in model parameters, Laplacian output of data, and steepness measure of data to detect anomalies.

TL;DR: In this article, the first and second derivatives of a short-time power spectrum with respect to frequency were used to estimate the temporal patterns of the fundamental frequency of speech signals, and an effective algorithm to calculate the derivatives is also proposed.

TL;DR: In this article, the authors presented a method for finding the magnitude group delay and phase group delay functions for complex-valued signals, based on the partial information of either the phase or magnitude of the Fourier transform of the signals.

TL;DR: The definition of the ‘block-space invariance’ property, which characterizes the above filters, is given and explicit relations are derived, which permit the determination of the scalar transfer function in terms of the elements of the transfer function matrix of the multivariable system and vice-versa.

TL;DR: Both recursive and non-recursive estimators are obtained by maximizing the spectral entropy, and these estimators preserve minimum information subject to the unknown autocovariance lags.

TL;DR: In this paper, a high-resolution spectral estimation method for 2-D isotropic random fields with covariance functions equal to weighted sums of cylindrical harmonics is presented, taking maximal advantage of the symmetries implied by both the isotropy and the special covariance structure of these fields.

TL;DR: The problem of aliasing associated with the computation of complex cepstrum through differential cepStrum is demonstrated with an example.