Showing papers in "Signal Processing in 1990"

TL;DR: Note: V. Madisetti, D. B. Williams, Eds.

TL;DR: This work seeks to convert the Gabor representation into a discrete and finite format that is directly suitable for numerical implementation, facilitating the selection of arbitrary window functions as well as arbitrary oversampling rates.

TL;DR: It is shown that difficulties associated with channel non-linearities and additive noise correlation can be overcome by the use of equalizers employing a multi-layer perceptron structure, providing further evidence that the neural network approach proposed recently by Gibson et al. is a general solution to the problem of equalization in digital communications systems.

TL;DR: It is shown that it is also necessary for a mathematically coherent application of morphological operators to grey-level images, and dilations and erosions can be defined directly with lattice-theoretic methods, without recourse to umbras.

TL;DR: In this paper, an efficient method to delineate topographic basins from digital elevation models is presented, which is based upon mathematical morphology and it consists of two major steps: removing all the pits within the model by using an original morphological mapping, and then delineating topographical basins by using morphological thinnings with specific structuring elements.

TL;DR: The Weighted Subspace Fitting (WSF) method is shown to be a unification of the subspace fitting techniques and the stochastic Maximum Likelihood method, valid for large amounts of data, in the area of sensor array processing.

TL;DR: In this article, extended Kalman filtering is applied to the problem of estimating the signal's frequency and the amplitudes and phases of the first m harmonic components of a periodic signal measured in noise.

TL;DR: A dual blocksize (DB) concept is introduced to improve the coding efficiency of the side information and visual appearance of the transmitted pictures and the motion vector components are differentially coded using variable word length (VWL) codes.

TL;DR: In this article, the authors developed the circular convolution-multiplication relationship for the discrete cosine transform (DCT) similar to that of the discrete Fourier transform (DFT) for the filter frequency response.

TL;DR: A digital image processing method to enhance fine structure contrasts and the results are illustrated by profiles and photographs, especially interesting is the application to pictures taken in a hazy atmosphere.

TL;DR: A simple example of a biased estimator whose mean square error (MSE) is less than the unbiased Cramer-Rao lower bound (UCRLB) is provided.

TL;DR: In this paper, edge-preserving smoothing techniques are compared by considering a test image which contains a central disk-shaped region with a step or a ramp edge against a uniform background.

TL;DR: A modification of the iterative algorithm for designing FIR filters by complex Chebyshev approximation introduced by Preuss is proposed, yielding a significant acceleration and the Newton interpolation formula is substituted by a Gaussian relaxation algorithm.

TL;DR: In this paper, the filter bank is organized as a parallel structure and the filters employed are 1st order IIR all-pass filters featuring very low computational complexity, and exact reconstruction in the absence of encoding/decoding.

TL;DR: The relevance of the local phase information for texture discrimination and image segmentation is studied and experimental results seem to confirm the importance of theLocal phase information.

TL;DR: Three subspace filtering techniques applicable to the matrix pencil method are presented briefly in a unified way andAbstract Poles of a linear time-invariant system can be extracted from a matrix pencil constructed from the transient response of the system.

TL;DR: It is shown that the multichannel Kalman filtering of color images in RGB or YIQ domains produces superior results compared to filtering each channel independently.

TL;DR: A novel type of algorithms for the discrete sine transform (DST) are introduced, using a basic trigonometric identity, to realize a successive reduction of the summation size in a simple manner, and therefore cause a very simple structure.

TL;DR: In this paper, a method for Wigner analysis of 2D real signals based on a 2D Hilbert transform is proposed, which is more easily exploitable than the WIGNer distribution of the 2-dimensional real signal.

TL;DR: The technique described in this paper is efficient when the residual unknown channel distortion is small, but iterations are needed to remove the estimation bias, andPolyspectral techniques, that could give unbiased solutions for any channel distortion, cannot be any better asymptotically.

TL;DR: In this article, a new and efficient design of FIR digital differentiators of second and higher orders for the low frequency range is proposed, and mathematical relations have been established between the weighting coefficients of the maximally linear (first order) FIR differentiator and those of the proposed (second and higher order) differentiator.

TL;DR: A parallel algorithm for weighted distance transforms that runs particularly efficiently on hierarchical cellular-logic machines, a subclass of the architectures known as pyramid machines, and is well-suited to the bit-serial processor architectures common in massively-parallel image processing.

TL;DR: It is shown that an interchange of the set of combining filters and separation filters preserves the crosstalk-free nature of transmultiplexer and the problem of channel distortion is alleviated by passing the received composite signal through a channel compensation filter or equalizer.

TL;DR: It is demonstrated how to realize arbitrary nonlinear memoryless functions on the basis of ΔΣM and the error bounds for the delta demodulator (DDM) averaging filter are given.

TL;DR: In this paper, a technique for designing a narrowband beamformer which is robust against array amplitude and phase perturbations is presented, where the approach is to constrain the mean-square-error between the desired unity response and the response of the beamformer over variation in amplitude and phases to be less than or equal to a small quantity and obtain a quadratic constraint on the weight vector.

TL;DR: A simple and fast zero tracking algorithm for adaptive array processing that is significantly faster and is almost independent of the external noise environment is presented.

TL;DR: In this paper, the asymptotic variances and covariances of the general HOYW frequency estimates were derived for sinusoidal frequency estimation, which is a significant extension of the previously available results, which considered only particular cases of HoyW estimates, such as the minimum-norm estimate.