1 // Ceres Solver - A fast non-linear least squares minimizer 2 // Copyright 2010, 2011, 2012 Google Inc. All rights reserved. 3 // http://code.google.com/p/ceres-solver/ 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: kushalav (at) google.com (Avanish Kushal) 30 // sameeragarwal (at) google.com (Sameer Agarwal) 31 // 32 // Functions to manipulate visibility information from the block 33 // structure of sparse matrices. 34 35 #ifndef CERES_INTERNAL_VISIBILITY_H_ 36 #define CERES_INTERNAL_VISIBILITY_H_ 37 38 #ifndef CERES_NO_SUITESPARSE 39 40 #include <set> 41 #include <vector> 42 #include "ceres/graph.h" 43 44 namespace ceres { 45 namespace internal { 46 47 struct CompressedRowBlockStructure; 48 49 // Given a compressed row block structure, computes the set of 50 // e_blocks "visible" to each f_block. If an e_block co-occurs with an 51 // f_block in a residual block, it is visible to the f_block. The 52 // first num_eliminate_blocks columns blocks are e_blocks and the rest 53 // f_blocks. 54 // 55 // In a structure from motion problem, e_blocks correspond to 3D 56 // points and f_blocks correspond to cameras. 57 void ComputeVisibility(const CompressedRowBlockStructure& block_structure, 58 int num_eliminate_blocks, 59 vector<set<int> >* visibility); 60 61 // Given f_block visibility as computed by the ComputeVisibility 62 // function above, construct and return a graph whose vertices are 63 // f_blocks and an edge connects two vertices if they have atleast one 64 // e_block in common. The weight of this edge is normalized dot 65 // product between the visibility vectors of the two 66 // vertices/f_blocks. 67 // 68 // This graph reflects the sparsity structure of reduced camera 69 // matrix/Schur complement matrix obtained by eliminating the e_blocks 70 // from the normal equations. 71 // 72 // Caller acquires ownership of the returned Graph pointer 73 // (heap-allocated). 74 Graph<int>* CreateSchurComplementGraph(const vector<set<int> >& visibility); 75 76 } // namespace internal 77 } // namespace ceres 78 79 #endif // CERES_NO_SUITESPARSE 80 #endif // CERES_INTERNAL_VISIBILITY_H_ 81
