In metal cutting, the state of a part's surface deformation layer is crucial for mechanical and physical properties of machined workpiece, which influences the modification of surface integrity such as distribution of residual stress, microhardness and microstructure. As a result, the machined surface layer has a great effect on service performance of the part. A image processing tool MATLAB was employed to recognize the machined surface deformation layer in this paper. The effect of the pre-analysis image ...