Abstract: In this paper，the principle that the light intensity would change after the light passed through the

polarizer is combined with the polarization photography technology and Matlab processing to separate the specular

reflection and the diffuse reflection of the obtained photograph. With the surface roughness increasing，the ratio of

the reduction of the specular reflection and the diffuse reflection is reduced. This result can be used to detect of the

surface roughness of the object.

Key words: polarization, roughness detection, specular reflection, diffuse reflection