1. Reconstructing smooth surfaces from partial noisy information;Barrow,1979
2. On seeing things;Clowes;Artif. Intell.,1971
3. Understanding image intensities;Horn;Artif. Intell.,1977
4. Impossible objects as nonsense sentences;Huffman,1971
5. Numerical shape from shading and occluding contours in a single view;Ikeuchi,1979