Measuring method for the line spread function of specular reflection

Gloss is evaluated based on not only the intensity of reflected light but also the sharpness of the light source image. In this paper, we discuss the line spread function of specular reflection (SR-LSF). We developed a measurement apparatus for the SR-LSF based on the visual inspection of gloss. The measurement results of six types of samples with different glossiness values are shown. These samples were measured using the point spread function of specular reflection reported previously by the authors to verify the SR-LSF. It is shown that the SR-LSF can be measured easily and efficiently from an image recorded for visual inspection.