fastPTOptimizer

This is a fork of Panorama Tools / libpano13-2.9.21 Mercurial.
PTOptimizer is part of panorama tools, a great software for aligning and stitching several partially overlapping photos in order to get a bigger photo. When you have only a small or medium number of images and control points, the original PTOptimizer does the optimization in a fairly short time.

However if you have a large number of images (several hundrets or more than thousand) and control points, PTOptimizer typically needs much time (up to several days) for the optimization of the parameters.

fastPTOptimizer decreases the processing time for large panoramas (a speedup factor of 100 or more can be achieved). This is possible by exploiting the sparseness of the mathematical optimization problem. The original PTOptimizer uses the well proven Levenberg Marquardt optimizer lmdif from the minpack software. fastPTOptimizer uses a "sparse" optimizer lmdif_sparse that uses the SuiteSparse library.