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Showing papers in "Signal Processing in 1988"


Journal ArticleDOI
TL;DR: In this paper, a hierarchical structured segmentation algorithm is presented, which is based on the hypothesis that an area to be segmented is defined by a set of uniform motion and position parameters denoted as mapping parameters.

210 citations


Journal ArticleDOI
TL;DR: An algorithm for data compression of grey level images based on coding geometric and grey level information of the contours in the image and using the Laplacian pyramid coding algorithm to give intelligible reconstructed images.

192 citations


Journal ArticleDOI
TL;DR: Two transformations are proposed in this paper that can be used for QRS detection in one-channel as well as in multi-channel ECGs, with very good performance.

132 citations


Journal ArticleDOI
TL;DR: In this article, the authors consider the motivations for current interest in the application of conjoint signal representations to problems in visual processing and form representation, and discuss the comparative capacities of these representations to provide high conjoint resolution.

112 citations


Journal ArticleDOI
TL;DR: Combined speech enhancement stress compensation preprocessing is shown to be extremely effective in reducing and even eliminating effects caused by stress and noise for robust automatic recognition.

102 citations


Journal ArticleDOI
TL;DR: A systematic framework is given that accommodates existing max-min filter methods and suggests new ones and can distinguish edges in ramp edges and texture (or noise) edges; all methods presented come in three versions: for edges, Ramp edges and non-ramp (“texture”) edges.

96 citations


Journal ArticleDOI
TL;DR: In this article, the spatial interaction is described by a Markov Random Field whose energy is chosen in order to preserve the edges, and an estimation method of the parameters is proposed that is performed before the restoration.

79 citations


Journal ArticleDOI
TL;DR: In this article, the authors examined speech enhancement techniques to be applied in a mobile radio environment and compared the performance of a noise-cancelling microphone approach and signal processing methods.

79 citations


Journal ArticleDOI
TL;DR: In this paper, a class of linear phase digital filters is discussed for which the filter coefficients are simple functions of the parameters determining the desired frequency response, and the filters are variable over nearly the whole frequency range from zero to half the sampling frequency.

59 citations


Journal ArticleDOI
TL;DR: In this article, four new measures based on the graylevel co-occurrence matrix, which in some way or other reflect the homogeneity in different regions of an image, were proposed for threshold selection.

58 citations


Journal ArticleDOI
TL;DR: In this article, a reduced order model Kalman filter (ROMKF) is proposed to reduce the dimension of the state representation by approximation and the use of the corresponding optimal filter directly.

Journal ArticleDOI
TL;DR: In this article, the authors describe several methods to perform template location in noisy images, as well as tests to compare their respective speed and accuracy, and the performances of the different methods have been evaluated.

Journal ArticleDOI
TL;DR: Both 3-lead and 1-lead ECG signals are used and QRS complexes are considered as events to be detected and a detection accuracy approximating 99% can be reported.

Journal ArticleDOI
TL;DR: It is shown that in the general case the resulting algorithms are implementable through the same computing schemes used for detection of linear structures except for a use of different filters, and the solution proposed by this general framework is presented.

Journal ArticleDOI
TL;DR: A new algorithm for smoothing synthetic aperture radar (SAR) images, which is based on the estimation of the most homogeneous neighbourhood around each image pixel, is presented.

Journal ArticleDOI
TL;DR: A motion-compensatinginterpolation filter is used in the new converter and a motion vector estimation and a segmentation are performed and incorrectly estimated vectors are eliminated by nonlinear postprocessing.

Journal ArticleDOI
TL;DR: A method for computing the short-time Fourier transform of a discrete-time signal by convolving it with one of a family of infinite-duration windows h(nT)=(nT)ke−αnT, k integer which greatly alleviates the problem of spectral leakage which is inherent in the more traditional DFT method.

Journal ArticleDOI
TL;DR: In this paper, the theory can be generalized to arbitrary complete atomic Boolean lattices with a commutative group structure on the set of atoms, and give some simple examples of such lattices.

Journal ArticleDOI
TL;DR: In this paper, generic formulas for obtaining optimal estimates of the reflection coefficient sequence are derived, which can utilize any estimation/smoothing scheme and yield optimal fixed-point, fixed-lag and fixed-interval estimates.

Journal ArticleDOI
TL;DR: In this paper, the situations for which non-stationary probabilistic correlation functions can be accurately estimated from a single sample path of a stochastic process are delineated.

Journal ArticleDOI
TL;DR: A pairwise classifier performs better than the other two classifiers as it shows the highest recognition rate and a hierarchical classifier which has the smallest character recognition time.

Journal ArticleDOI
TL;DR: Very satisfactory syntheses are obtained for the stochastic and slightly structured textures by using about 20 to 30 features of the texture model by synthesizing textures from these features.

Journal ArticleDOI
TL;DR: In this paper, the authors show that analytic signal-based spectral estimators can achieve higher resolution than their real signal counterparts, due to the phase-invariance property of an analytic signal.

Journal ArticleDOI
TL;DR: In this article, a class of tapped delay line filter structures whose frequency responses approximate that of an arbitrary delay in the maximally flat sense is presented, which has the advantage that the delay desired is controlled by a number of identical multipliers and a phase shifter whose values are proportional to the desired delay.


Journal ArticleDOI
TL;DR: The necessary image processing elements for such systems, including command interpreter, macro command system and Window Management System, are discussed, which demonstrate clearly the possibilities of image processing with PCs.

Journal ArticleDOI
TL;DR: In this article, a new approach is proposed based on reconstruction of a regularly sampled signal and nonlinear spectral analysis, which gives better results than traditional methods based on discrete Fourier transforms, particularly with short data records.

Journal ArticleDOI
TL;DR: It is observed that transients can be completely eliminated by changing the state vector at the time network parameters are changed by simulations on two second order and two fifth order networks.

Journal ArticleDOI
TL;DR: In this article, the authors developed an algorithm for diffraction tomography which involves iterations on successive ray tracing and tomographic inversion, which can yield very accurate reconstructions in a few iterations.

Journal ArticleDOI
TL;DR: Even-odd transforms such as the discrete cosine (DCT), the discrete sine, the slant (ST), and the discrete Legendre (DLT) transforms are developed from the Walsh-Hadamard transform (WHT).