---
title: "Surface-Normals from Closed Paths"
authors:
  - "Michael J. Brooks"
doi: ""
url: "https://ijcai.org/proceedings/1979/27"
pdf: "https://ijcai.org/proceedings/1979/0027.pdf"
venue: "Proceedings of the Sixth International Joint Conference on Artificial Intelligence"
year: 1979
pages: ""
track: ""
keywords:
---

# Surface-Normals from Closed Paths

Michael J. Brooks

*Proceedings of the Sixth International Joint Conference on Artificial Intelligence*.

## Abstract

It is now well established that the shading present in an image of an object is a potential source of 3-D shape information. With this in mind, we seek constraints arising out of the assumption that an image portrays an object with a smooth surface, On obtaining a threshold and a depth-invariance constraint (the latter requiring integration around closed curves) we offer a method of shape from shading for the purpose of demonstrating their potential usefulness.