Solving structure from motion
•Minimizing g is difficult:
–g is non-linear due to rotations, perspective division
–lots of parameters: 3 for each 3D point, 6 for each camera
–difficult to initialize
–gauge ambiguity: error is invariant to a similarity transform (translation, rotation, uniform scale)
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•Many techniques use non-linear least-squares (NLLS) optimization (bundle adjustment)
–Levenberg-Marquardt is one common algorithm for NLLS
–Lourakis, The Design and Implementation of a Generic Sparse Bundle Adjustment Software Package Based on the Levenberg-Marquardt Algorithm, http://www.ics.forth.gr/~lourakis/sba/
–http://en.wikipedia.org/wiki/Levenberg-Marquardt_algorithm
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