Surface speckle pattern intensity distribution resulting from laser light scattering from a rough surface contains various information about the geometrical and physical properties of the surface.A texture analysis method based on spatial filtering is used to analyze speckle patterns of grinding surface.The feature parameters of speckle texture with a good monotonic relation related to the surface roughness (Ra) are extracted.The basic principle of the texture analysis is to extract three types of vectors based on fractional Brownian motion model of window speckle images,which are the normalized scale range vector,the normalized pixel pair number vector,and the normalized multiscale intensity difference (NMSID) vector,then to make a NMSID vector transformation for speckle patterns,and finally statistically to investigate both the transformed images with zero gray pixels and the transformed images without zero gray pixels.The analysis results show that both texture features energy and new entropy of the transformed images have a good monotonic relation with surface roughness value Ra.