This software implements a method for the n-point pose determination problem that directly minimizes the corresponding nonlinear least-squares cost function to obtain up to four solutions.
The method was presented at the International Conference on Computer Vision (ICCV) 2011. See paper [C11]

Joel A. Hesch and Stergios I. Roumeliotis. A Direct Least-Squares (DLS) Method for PnP. In Proc. of the Int. Conf. on Computer Vision, Barcelona, Spain, November 6-13, 2011.

Download the fast matlab version (updated 05/17/12): link

Revision history:

• 05/17/12 - Added "robust" dls_pnp version which avoids the singular configuration of the Cayley paremeters by solving the system 3 times (with the original system centered, and rotated about the x/y/z axes, respectively).
• 11/15/11 - Uploaded "fast" matlab version, which skips most of the intermediate computations, and forms the multiplication matrix directly. Run times on my laptop (core2 duo, 2.4GHz) were (i) 8 ms for small sized problems (~10 pts), (ii) 19 ms for medium sized problems (~100 pts), and (iii) 100 ms for larger sized problems (1000 pts). Stay tuned for a C++ implementation.
• 11/10/11 - Initial upload of matlab version, follows the paper derivations.