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@google.com (Avanish Kushal) 30// sameeragarwal@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// This include must come before any #ifndef check on Ceres compile options. 39#include "ceres/internal/port.h" 40 41#ifndef CERES_NO_SUITESPARSE 42 43#include <set> 44#include <vector> 45#include "ceres/graph.h" 46 47namespace ceres { 48namespace internal { 49 50struct CompressedRowBlockStructure; 51 52// Given a compressed row block structure, computes the set of 53// e_blocks "visible" to each f_block. If an e_block co-occurs with an 54// f_block in a residual block, it is visible to the f_block. The 55// first num_eliminate_blocks columns blocks are e_blocks and the rest 56// f_blocks. 57// 58// In a structure from motion problem, e_blocks correspond to 3D 59// points and f_blocks correspond to cameras. 60void ComputeVisibility(const CompressedRowBlockStructure& block_structure, 61 int num_eliminate_blocks, 62 vector<set<int> >* visibility); 63 64// Given f_block visibility as computed by the ComputeVisibility 65// function above, construct and return a graph whose vertices are 66// f_blocks and an edge connects two vertices if they have atleast one 67// e_block in common. The weight of this edge is normalized dot 68// product between the visibility vectors of the two 69// vertices/f_blocks. 70// 71// This graph reflects the sparsity structure of reduced camera 72// matrix/Schur complement matrix obtained by eliminating the e_blocks 73// from the normal equations. 74// 75// Caller acquires ownership of the returned Graph pointer 76// (heap-allocated). 77Graph<int>* CreateSchurComplementGraph(const vector<set<int> >& visibility); 78 79} // namespace internal 80} // namespace ceres 81 82#endif // CERES_NO_SUITESPARSE 83#endif // CERES_INTERNAL_VISIBILITY_H_ 84