In the domain of mechanical manufacture

the information from product surface was vitally important to supervising the surface manufacture. Compared with 2-Dimensional (2-D) information

the 3-Dimensional (3-D) information of surface texture as a hot research topic could more fully present the characteristics of machined surface. For the existence of vibration coming from mechanical transmission system and environment

the extracted surface by contact measurement sometimes included error ingredients

which presented characters of singularity. At present

wavelet transform was very useful to signal processing. In order to exclude the error ingredients mentioned above

a wavelet singularity analysis was adopted in the surface evaluation. Its principle and implementation algorithm were described in detail. In the experiment

the wavelet singularity analysis was used to preprocess the measured data first

and then the roughness profile was extracted by wavelet filter and Gaussian filter

the 3-D roughness results of which wre compared with each other. The computation and comparison proved that the algorithm was valid and more reasonable evaluation results could be obtained.