We present a general comparison of punctual kriging based image restoration for different neighbourhood sizes. The formulation of the technique under consideration is based on punctual kriging and fuzzy concepts for image restoration in spatial domain. Three different neighbourhood windows are considered to estimate the semivariance at different lags for studying its effect in reduction of nega...

Abstract: Exact and explicit expressions for the variogram of first–order intrinsic autoregressions have not been known. Various asymptotic expansions and approximations have been used to compute the variogram. In this note, an exact and explicit expression applicable for all parameter values is derived. The expression involves Appell’s hypergeometric function of the fourth kind. Various partic...

A detailed introduction to variogram analysis of reflectance data is provided, and variogram parameters (nugget, sill, and range values) were examined as possible indicators of abiotic (irrigation regime) and biotic (spider mite infestation) stressors. Reflectance data was acquired from 2 maize hybrids (Zea mays L.) at multiple time points in 2 data sets (229 hyperspectral images), and data fro...

Geostatistics deals with spatial and temporal data from natural phenomena and involves estimating values of regionalized variables. In this analysis the fundamental tool is the variogram that is a variability measure; for example, geological variability related to distance. The variogram shows the degree of spatial dependence between samples for a specific support. The squared differences betwe...

The aim of the presentation is to investigate acoustic analysis of connected speech by means of an average-equalized and energy-equalized variogram to extract vocal dysperiodicities. The variogram enables positioning a current and a lagged analysis frame in adjacent speech cycles to track inter-cycle dysperiodicities. Average and energy equalization of the analysis frames are options that make ...

We present a fast sequential assimilation technique for conditioning wave simulations using buoy data. It is based on non-stationary kriging that uses a separable space-time variogram. This variogram is estimated from the history of simulations, as a collection of maps of variances of increments between the logarithms of simulated and observed wave heights. The method finally provides a set of ...

This paper presents a new method for unsupervised urban area extraction from SAR imagery. The image segmentation method combines variogram texture feature extraction with OTSU threshold segmentation method, to obtain the result as good as traditional classical algorithm and have much higher computational efficiency. TerraSAR-X image is used to validate the proposed method, and experimental resu...

A generalized variogram is used to track vocal dysperiodicities in connected speech, which are summarized by means of a signal-to-dysperiodicity marker. To evaluate the variogram-based analysis, signal-to-dysperiodicity estimates are correlated with scores obtained by means of perceptual ratings of the degree of hoarseness, which are based on comparative judgments of pairs of speech samples. Th...

Recent studies have attempted to optimize the configuration of sample sites for estimation of the variogram by the usual method-of-moments. This paper shows that objective functions can readily be defined for estimation by the method of maximum likelihood. In both cases an objective function can only be defined for a specified variogram so some prior knowledge about the spatial variation of the...

The effect of outliers on estimates of the variogram depends on how they are distributed in space. The ‘spatial breakdown point’ is the largest proportion of observations which can be drawn from some arbitrary contaminating process without destroying a robust variogram estimator, when they are arranged in the most damaging spatial pattern. A numerical method is presented to find the spatial bre...