1 // Ceres Solver - A fast non-linear least squares minimizer 2 // Copyright 2015 Google Inc. All rights reserved. 3 // http://ceres-solver.org/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are met: 7 // 8 // * Redistributions of source code must retain the above copyright notice, 9 // this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above copyright notice, 11 // this list of conditions and the following disclaimer in the documentation 12 // and/or other materials provided with the distribution. 13 // * Neither the name of Google Inc. nor the names of its contributors may be 14 // used to endorse or promote products derived from this software without 15 // specific prior written permission. 16 // 17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 18 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 21 // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 // POSSIBILITY OF SUCH DAMAGE. 28 // 29 // Author: sameeragarwal@google.com (Sameer Agarwal) 30 // 31 // Detailed descriptions of these preconditions beyond what is 32 // documented here can be found in 33 // 34 // Bundle Adjustment in the Large 35 // S. Agarwal, N. Snavely, S. Seitz & R. Szeliski, ECCV 2010 36 // http://www.cs.washington.edu/homes/sagarwal/bal.pdf 37 38 #ifndef CERES_INTERNAL_SCHUR_JACOBI_PRECONDITIONER_H_ 39 #define CERES_INTERNAL_SCHUR_JACOBI_PRECONDITIONER_H_ 40 41 #include <memory> 42 #include <set> 43 #include <utility> 44 #include <vector> 45 46 #include "ceres/preconditioner.h" 47 48 namespace ceres { 49 namespace internal { 50 51 class BlockRandomAccessDiagonalMatrix; 52 class BlockSparseMatrix; 53 struct CompressedRowBlockStructure; 54 class SchurEliminatorBase; 55 56 // This class implements the SCHUR_JACOBI preconditioner for Structure 57 // from Motion/Bundle Adjustment problems. Full mathematical details 58 // can be found in 59 // 60 // Bundle Adjustment in the Large 61 // S. Agarwal, N. Snavely, S. Seitz & R. Szeliski, ECCV 2010 62 // http://www.cs.washington.edu/homes/sagarwal/bal.pdf 63 // 64 // Example usage: 65 // 66 // Preconditioner::Options options; 67 // options.preconditioner_type = SCHUR_JACOBI; 68 // options.elimination_groups.push_back(num_points); 69 // options.elimination_groups.push_back(num_cameras); 70 // SchurJacobiPreconditioner preconditioner( 71 // *A.block_structure(), options); 72 // preconditioner.Update(A, NULL); 73 // preconditioner.RightMultiply(x, y); 74 // 75 class SchurJacobiPreconditioner : public BlockSparseMatrixPreconditioner { 76 public: 77 // Initialize the symbolic structure of the preconditioner. bs is 78 // the block structure of the linear system to be solved. It is used 79 // to determine the sparsity structure of the preconditioner matrix. 80 // 81 // It has the same structural requirement as other Schur complement 82 // based solvers. Please see schur_eliminator.h for more details. 83 SchurJacobiPreconditioner(const CompressedRowBlockStructure& bs, 84 const Preconditioner::Options& options); 85 SchurJacobiPreconditioner(const SchurJacobiPreconditioner&) = delete; 86 void operator=(const SchurJacobiPreconditioner&) = delete; 87 88 virtual ~SchurJacobiPreconditioner(); 89 90 // Preconditioner interface. 91 void RightMultiply(const double* x, double* y) const final; 92 int num_rows() const final; 93 94 private: 95 void InitEliminator(const CompressedRowBlockStructure& bs); 96 bool UpdateImpl(const BlockSparseMatrix& A, const double* D) final; 97 98 Preconditioner::Options options_; 99 std::unique_ptr<SchurEliminatorBase> eliminator_; 100 // Preconditioner matrix. 101 std::unique_ptr<BlockRandomAccessDiagonalMatrix> m_; 102 }; 103 104 } // namespace internal 105 } // namespace ceres 106 107 #endif // CERES_INTERNAL_SCHUR_JACOBI_PRECONDITIONER_H_ 108