Ulupinar F.Nevatia, R.2016-02-082016-02-0819931628828http://hdl.handle.net/11693/26088Inference of 3-D shape from 2-D contours in a single image is an important problem in machine vision. We survey classes of techniques proposed in the past and provide a critical analysis. We propose that two kinds of symmetries in figures, which are known as parallel and skew symmetries, give significant information about surface shape for a variety of objects. We derive the constraints imposed by these symmetries and show how to use them to infer 3-D shape. We discuss the zero Gaussian curvature (ZGC) surfaces in depth and show results on the recovery of surface orientation for various ZGC surfaces. © 1993 IEEEEnglishGaussian curvature surfacesShape from contoursymmetry analysiszeroConstraint theoryContour measurementImage analysisImaging techniquesPattern recognitionThree dimensionalMidlevel visionParallel symmetriesShape from contourSkew symmetriesSymmetry analysisThree dimensional surfacesZero Gaussian curvature (ZGC) surfacesComputer visionArticle10.1109/34.184771