“…But with the development of 3D measuring techniques especially faster optimal methods, a lot of data can be obtained from engineering surfaces in quite a short time [5,6], it is inappro priate to simply use one-dimensional (ID) parameters to character ize surface textures. Consequently, more surface characterization approaches have been proposed to obtain abundant information about 3D surfaces, such as a 3D parameter set [4,[7][8][9], gray level co-occurrence matrix [10], two-dimensional (2D) autocorrelation function and spectral analysis [11], and a 3D Monte Carlo model [12], In recent years, some approaches that first used in signal processing areas have been adopted to extract features of engi neering surfaces, such as Gabor filter banks [13], Gaussian filter banks [14], and wavelet packets [15][16][17], and after filtering, some numerical surface parameters are calculated for each sub-band to represent a given surface. The goal of feature extraction is to improve the effectiveness and efficiency of classification.…”