{"type":"ScholarlyArticle","title":"The Line of Curvature Constraint and the Interpretation of 3-D Shape From Parallel Surface Contours","authors":[{"name":"Kemt A. Stevens","slug":"kemt-a-stevens","given":"Kemt A.","family":"Stevens","affiliation":""}],"abstract":"Human vision is adep t at inferrin g surface shape f rom a projection of curves lyin g across a surface, particularly from parallel undulatin g curves. Since the image projection los es 3-D information, the interpretation must be constrained by certain a priori assumptions. A theory of constraint on this problem [St e vens 198la) proposes three assumptions, n amely that n ei ther the viewpoint nor the placement of th e physical curves on the surface is misleading (two formof gene ral position), and that the physical curves are lines of curvature ac ross the surface. It follows that parallel contours in anima ge correspond to parallel curv es across an app roxim a t e ly cylindrical surface, and since the lin es of curvature on a cylinder are ge odesic and planar, one may reconstruct the image projection of an orthogonal net covering the surface. There is sufficient information available to estimate surface orientation at certain strongly constrained points, then to determine, g iven the geo desic and planarity properties, the surface orientation e ls ewhe re by a simple extrapolation method. An implem en tation of this computation predicts local surface orientation that closely matches the orientation we perceive, thereby supporting the theory that our visual iiterpretation of surface shape from parallel contours embodies the line of curvature constraint.","doi":null,"url":"https://ijcai.org/proceedings/1983/245","pdf":"https://ijcai.org/proceedings/1983/0245.pdf","markdown":"https://ijcai.org/proceedings/1983/245.md","bibtex":"https://ijcai.org/proceedings/1983/bibtex/245","volume":{"slug":"1983","title":"Proceedings of the Eighth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 1983","url":"https://ijcai.org/proceedings/1983/","year":1983,"location":"Karlsruhe, West Germany","dates":"","editors":"Alan Bundy","isbn":"","publisher":"International Joint Conferences on Artificial Intelligence","doi_prefix":""},"section":"Vision","track":"Vision","number":245,"pages":{"first":1057,"last":1060},"keywords":[],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}