Add the number of effective parameters to the final report.

Here is an example report, obtained by running:

  bin/Debug/bundle_adjuster \
  --input=../ceres-solver/data/problem-16-22106-pre.txt \
  --linear_solver=iterative_schur \
  --num_iterations=1 \
  --alsologtostderr \
  --use_local_parameterization \
  --use_quaternions

Note that effective parameters is less than parameters by 16, which is the
number of cameras. In this case the local parameterization has a 3 dimensional
tangent space for the 4-dimensional quaternions.

Ceres Solver Report
-------------------
                                     Original                  Reduced
Parameter blocks                        22138                    22138
Parameters                              66478                    66478
Effective parameters                    66462                    66462
Residual blocks                         83718                    83718
Residual                               167436                   167436

Minimizer                        TRUST_REGION
Trust Region Strategy     LEVENBERG_MARQUARDT

                                        Given                     Used
Linear solver                 ITERATIVE_SCHUR          ITERATIVE_SCHUR
Preconditioner                         JACOBI                   JACOBI
Threads:                                    1                        1
Linear solver threads                       1                        1
Linear solver ordering              AUTOMATIC                22106, 32

Cost:
Initial                          4.185660e+06
Final                            7.221647e+04
Change                           4.113443e+06

Number of iterations:
Successful                                  1
Unsuccessful                                0
Total                                       1

Time (in seconds):
Preprocessor                            0.697

  Residual Evaluations                  0.063
  Jacobian Evaluations                 27.608
  Linear Solver                        13.360
Minimizer                              43.973

Postprocessor                           0.004
Total                                  44.756

Termination:                   NO_CONVERGENCE

Change-Id: I6b6b8ac24f71bd187e67d95651290917642be74f
3 files changed