Evaluation for Micro Surface Topography Based on Multi-fractal Spectrum

Aiming at the deficiency of traditional method in evaluating micro surface topography, an evaluation method is advanced based on multi-fractal spectrum. In this method, the probability measure of the gray image of micro surface topography is counted in the improved box-counting method, and the multi-fractal spectrums are extracted by the Legendre transformation of scale exponent. Based on the multi-fractal spectrum, the spectrum width, height interval and asymmetry degree are extracted, and micro surface topography are evaluated according to the parameters. Evaluation experiments of surface topographies are carried out to prove the value of multi-fractal spectrums, and the result shows that multi-fractal spectrum can overcome the deficiency of traditional method, and surface topography can be evaluated accurately by its parameters.