Fractal Characteristics of Luminance Distributions on a Male Head Statue and Its Modeling Effect

This paper describes fractal characteristics of luminance distribution on a male head statue made of plaster to express quantitatively modeling effect of the statue. The luminance distributions of the statue were measured by photographic photometry and CCD photometry methods. Both measured data obtained under various luminous environments were analyzed using the box-counting method. It was found that the distributions showed fractal characteristics in both methods and the main factors to determine the fractal dimensions were an image resolution of the photometry methods and vertical angle of the light sources. The fractal dimension decrease due to low resolution corresponded to indistinctness of the luminance distribution. On the other hand, the fractal dimension decrease due to low vertical angle corresponded to emphasizing the shadow. Paying attention to the latter fact, it was considered that the fractal dimension was useful as a modeling index of a human face under the condition that an image resolution was kept constant.