“…Spectral methods are based on the Fourier transform, analysing the power spectrum (Matsuyama, 1980). The third and most important group in texture analysis corresponds to that of statistical methods, which are mainly based on local statistical parameters (Sun and Qin, 1993), entropy (Haralick and Shanmugham, 1974), fractal dimension (Dawson and Parsons, 1994), and measures of the matrix of co-occurrence (Franklin and Peddle, 1987). Other studies have made use of texture transforms (Irons and Petersen, 1981) in which dierent measures of variability in digital number (DN) values are estimated within moving windows, e.g., standard deviation (Arai, 1993) or local variance (Woodcock and Harward, 1992), and some recent techniques have involved the use of geostatistical parameters deduced from the variogram function (Carr, 1996;Lark, 1996;Miranda et al, 1998).…”