Surface-normals from closed paths

Understanding Line drawings of Scenes with Shadows

1975 • 897 citations

Obtaining Shape from Shading Information

1975 • 409 citations

Image Intensity Understanding

1975 • 106 citations

A cooperative algorithm for determining surface orientation from a single view

1977 • 54 citations

The Penrose Triangle and a Family of Related Figures

1978 • 50 citations

A Numerical Method for Shape-From-Shading from a Single Image.

1979 • 31 citations