Abstract
This paper presents an image transformation method between Japanese fans and their unfolded pictures. The transformation from 2D pictures to 3D fans depends on the number and positions of folding lines, which makes the analysis complicated. In order to avoid this complication, we consider the extreme state in which the number of the folding lines approaches to infinity and the width of the strips approaches to zero. This state corresponds to the orthographic projection of the fan. The proposed method requires only the outline shape of the picture, the center and the angle of the fun, and hence can be used as a convenient tool for the analysis of the distortion of fan pictures.
