Recognition of Surface Roughness Based on Fractal Theory and the Microscopic Images

Values of surface roughness are usually unstable with conventional measurement methods because of the affection of measurement resolution and signal sampling, in order to make the measurement results reflect the practical engineering surface accurately, a new method of measuring surface roughness based on microscopic images and fractal theory is proposed. The microscopic images are acquired and pretreated, the structure function method is used to calculate the fractal dimension and fractal proportion coefficient, experiment results show that the fractal dimensions of tested samples with same making method are equal basically, while the fractal proportion coefficients are changed with different surface roughness, the two parameters can express the surface state preferably.