1. Solid Shape;Koenderink,1990
2. Scale-space filtering;Witkin,1983
3. The structure of images;Koenderink;Trans. Biol. Cyb.,1984
4. Representation based on zero-crossings in scale-space;Hummel,1986
5. Scaling theorems for zero-crossings;Yuille;IEEE Trans. PAMI,1988