Journal ArticleDOI
On shape from shading
TLDR
A new method is presented for the recovery of a bivariate function H(x, y) that describes a “nice,” almost everywhere differentiable height profile, from shading information, based on a recursive way of determining equal-height or level contours of the surface starting at a given level curve.Abstract:
We present a new method for the recovery of a bivariate function H(x, y) that describes a “nice,” almost everywhere differentiable height profile, from shading information. The given shading data is assumed to be a result of diffuse, Lambertian reflection of light from the surface. This implies that, if the scene is uniformly illuminated from above, the shading yields information on the cosine of the angle between the vertical and the surface normal at each point. Given the shading information in the plane, the shape from shading problem is to determine all height profiles consistent with the data, and some boundary conditions, such as points of known height and surface orientation, or height profiles along continuous curves in the image plane. The new shape-from-shading method that we discuss is based on a recursive way of determining equal-height or level contours of the surface starting at a given level curve.read more
Citations
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Journal ArticleDOI
Global Minimum for Active Contour Models: A Minimal Path Approach
Laurent D. Cohen,Ron Kimmel +1 more
TL;DR: A new boundary detection approach for shape modeling that detects the global minimum of an active contour model’s energy between two end points and explores the relation between the maximum curvature along the resulting contour and the potential generated from the image.
Patent
Depth mapping using projected patterns
TL;DR: In this article, a light source transilluminates the single transparency with optical radiation so as to project the pattern onto the object, and a processor processes the image captured by the image capture assembly to reconstruct a 3D map of the object.
Journal ArticleDOI
Path Planning for Autonomous Underwater Vehicles
TL;DR: This work develops an algorithm, called FM*, to efficiently extract a 2-D continuous path from a discrete representation of the environment and takes underwater currents into account thanks to an anisotropic extension of the original FM algorithm.
Book ChapterDOI
Shape From Shading
Emmanuel Prados,Olivier Faugeras +1 more
TL;DR: This chapter describes the main difficulties of the Shape From Shading problem and the most recent theoretical results and gives some examples of realistic modeling and of rigorous numerical methods.
Journal ArticleDOI
Numerical methods for shape-from-shading: A new survey with benchmarks
TL;DR: This paper provides a brief description of each method, highlighting its basic assumptions and mathematical properties, and proposes some numerical benchmarks in order to compare the methods in terms of their efficiency and accuracy in the reconstruction of surfaces corresponding to synthetic, as well as to real images.
References
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Journal ArticleDOI
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Journal ArticleDOI
Photometric Method For Determining Surface Orientation From Multiple Images
TL;DR: In this paper, a novel technique called photometric stereo is introduced, which is to vary the direction of incident illumination between successive images, while holding the viewing direction constant, and it is shown that this provides sufficient information to determine surface orientation at each image point.
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Partial differential equations
TL;DR: In this article, the authors focus on the quasilinear PDEs of second order, where the second derivatives of u appear in linear order only (i.e., in linear time).
Book
Numerical shape from shading and occluding boundaries
TL;DR: An iterative method for computing shape from shading using Occluding boundary information iteratively, using occluding boundaries information to supply boundary conditions and good initial values are found at certain points to help reduce the number of iterations required to reach a reasonable solution.