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Many algorithms have been suggested for the shape-from-shading problem, and some years have passed since the publication of the survey paper by Zhang et al. [1]. In this new survey paper, we try to update their presentation including some recent methods which seem to be particularly representative of three classes of methods: methods based on partial(More)
The Shape-from-Shading problem is a classical problem in image processing. Despite the huge amount of articles that deal with it, few real applications have been developed because the usual assumptions considered in the theory are too restrictive. Only recently two new PDE models have been proposed in order to include in the model the perspective(More)
Rapport de recherche IRIT N • 2004–2–R janvier 2004 Résumé Plusieurs algorithmes ontété proposés pour résoudre leprobì eme du shape from shading, et la publication du livre de Horn et Brooks [27] commencè a dater. Dans ce rapport, nous faisons un tour d'horizon le plusà jour possible, en détaillant plusieurs algorithmes qui nous semblentparticulì erement(More)
A numerical scheme to solve the Dirichlet type problem for the first order Hamilton-Jacobi equation related to the shape-from-shading model is proposed. The algorithm computes the maximal solution of the problem provided a compatibility condition on the dis-cretization steps is satisfied. This global formulation a~ows to include in the model the(More)
A narcissistic personality can be seen as arising from a number of separate dimensions of mental life: (a) a characteristic set of states of mind; (b) alterations in metacognitive skills—in particular a difficulty in accessing one's own inner states, desires, and emotions—and a difficulty in understanding another's mind from a decentrated perspective; (c)(More)
In this paper we study a modern, perspective model for shape from shading and its numerical approximation. We show that a new form of the classic concave/convex ambiguity is still present, although the model has been shown to be well-posed under particular assumptions. This analytical result is confirmed by various numerical tests. Moreover, we present(More)