Applied Scientist, 416-2 Uwanodai, Fukaya 366, Japan
(Received December 22, 1991; Accepted February 3, 1992)
Keywords: Similarity of Plane Figures, Hilbert Space, Inner Product, Jigsaw Puzzles
Abstract. A general method is given to describe plane figures as complex-valued functions. Quantitative and qualitative similarities of plane figures are defined by using a concept of Hilbert space. This method is applicable to letters and characters as well as closed and open figures. Theoretical result seems to be reasonable.