1. Techniques for the digital computer analysis of chain encoded arbitrary plane figures;Freeman,1961
2. On the computer classification of geometric line patterns;Freeman,1962
3. Fourier descriptors for plane closed curves;Zahn;IEEE Trans. Computers C-21,1972
4. A parallel mechanism for describing silhouettes;Sklansky;IEEE Trans. Computers C-21,1972
5. Recognizing three-dimensional objects by their silhouettes;Sklansky;J. Soc. Photo-Opt. Instrum. Eng.,1971