Departmental Papers (CIS)

Date of this Version


Document Type

Conference Paper


Suggested Citation:
Zhu, Q. and J. Shi. (2006). "Shape from Shading: Recognizing the Mountains through a Global View." Proceedings of the 2006 IEEE Computer Society Conference on Computer Vision and Pattern Recognition. New York, New York. June 17-22, 2006.

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Resolving local ambiguities is an important issue for shape from shading (SFS). Pixel ambiguities of SFS can be eliminated by propagation approaches. However, patch ambiguities still exist. Therefore, we formulate the global disambiguation problem to resolve these ambiguities. Intuitively, it can be interpreted as flipping patches and adjusting heights such that the result surface has no kinks. The problem i s intractable because exponentially many possible configurations need to be checked. Alternatively, we solve the integrability testing problem closely related to the original one. It can be viewed as finding a surface which satisfies the global integrability constraint. To encode the constraints, we introduce a graph formulation called configuration graph. Searching the solution on this graph can be reduced to a Max-cut problem and its solution is computable using semidefinite programming (SDP) relaxation. Tests carried out on synthetic and real images show that the global disambiguation works well fro complex shapes.


Date Posted: 12 October 2010

This document has been peer reviewed.