In this paper, a study of the illumination effects on the objective evaluation of fabric pilling was conducted for the purpose of optimization and validation of image analysis methods. A simple theoretical reflectance model of fabric surface with pills was presented in the consideration of its pill height, its pill width, and the incidence angle of illumination. Our investigation shows that the bi-directional illumination can achieve a better imaging result than one-side illumination, and it is reasonable to evaluate fabric pilling based on image analysis and template matching method.
