Abstract
Surface roughness and specular glossiness are generally used as evaluation indexes of processing surfaces. In evaluating a metal surface, it is important to know how external fineness of the processing surface and an ideal specular surface are different. Here, this difference is called a “specular rate”. It is impossible to evaluate specular rate using surface roughness or specular glossiness. Consequently, this paper considers new evaluation indexes for quantitatively evaluating specular rate of a metal surface. First, the method for estimating the impulse response between a certain pattern image and it's reflected image on an evaluated surface is proposed. This impulse response indicates the optical sharpness of a reflected image. Then, the surface's specular rate and directionality indexes are defined by estimated impulse response. The validity of these indexes has been verified by surface evaluation experiments on processed SUS304 stainless steel samples.
