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Open Source Computer Vision Library
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606 lines
21 KiB
606 lines
21 KiB
/*M/////////////////////////////////////////////////////////////////////////////////////// |
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// |
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// IMPORTANT: READ BEFORE DOWNLOADING, COPYING, INSTALLING OR USING. |
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// |
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// By downloading, copying, installing or using the software you agree to this license. |
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// If you do not agree to this license, do not download, install, |
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// copy or use the software. |
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// |
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// |
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// License Agreement |
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// For Open Source Computer Vision Library |
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// |
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// Copyright (C) 2000-2008, Intel Corporation, all rights reserved. |
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// Copyright (C) 2009, Willow Garage Inc., all rights reserved. |
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// Third party copyrights are property of their respective owners. |
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// |
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// Redistribution and use in source and binary forms, with or without modification, |
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// are permitted provided that the following conditions are met: |
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// |
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// * Redistribution's of source code must retain the above copyright notice, |
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// this list of conditions and the following disclaimer. |
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// |
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// * Redistribution's in binary form must reproduce the above copyright notice, |
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// this list of conditions and the following disclaimer in the documentation |
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// and/or other materials provided with the distribution. |
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// |
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// * The name of the copyright holders may not be used to endorse or promote products |
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// derived from this software without specific prior written permission. |
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// |
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// This software is provided by the copyright holders and contributors "as is" and |
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// any express or implied warranties, including, but not limited to, the implied |
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// warranties of merchantability and fitness for a particular purpose are disclaimed. |
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// In no event shall the Intel Corporation or contributors be liable for any direct, |
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// indirect, incidental, special, exemplary, or consequential damages |
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// (including, but not limited to, procurement of substitute goods or services; |
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// loss of use, data, or profits; or business interruption) however caused |
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// and on any theory of liability, whether in contract, strict liability, |
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// or tort (including negligence or otherwise) arising in any way out of |
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// the use of this software, even if advised of the possibility of such damage. |
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// |
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//M*/ |
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#include <algorithm> |
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#include <sstream> |
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#include "autocalib.hpp" |
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#include "motion_estimators.hpp" |
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#include "util.hpp" |
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using namespace std; |
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using namespace cv; |
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////////////////////////////////////////////////////////////////////////////// |
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struct IncDistance |
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{ |
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IncDistance(vector<int> &dists) : dists(&dists[0]) {} |
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void operator ()(const GraphEdge &edge) { dists[edge.to] = dists[edge.from] + 1; } |
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int* dists; |
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}; |
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struct CalcRotation |
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{ |
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CalcRotation(int num_images, const vector<MatchesInfo> &pairwise_matches, vector<CameraParams> &cameras) |
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: num_images(num_images), pairwise_matches(&pairwise_matches[0]), cameras(&cameras[0]) {} |
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void operator ()(const GraphEdge &edge) |
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{ |
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int pair_idx = edge.from * num_images + edge.to; |
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double f_from = cameras[edge.from].focal; |
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double f_to = cameras[edge.to].focal; |
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Mat K_from = Mat::eye(3, 3, CV_64F); |
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K_from.at<double>(0, 0) = f_from; |
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K_from.at<double>(1, 1) = f_from; |
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Mat K_to = Mat::eye(3, 3, CV_64F); |
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K_to.at<double>(0, 0) = f_to; |
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K_to.at<double>(1, 1) = f_to; |
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Mat R = K_from.inv() * pairwise_matches[pair_idx].H.inv() * K_to; |
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cameras[edge.to].R = cameras[edge.from].R * R; |
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} |
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int num_images; |
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const MatchesInfo* pairwise_matches; |
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CameraParams* cameras; |
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}; |
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void HomographyBasedEstimator::estimate(const vector<ImageFeatures> &features, const vector<MatchesInfo> &pairwise_matches, |
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vector<CameraParams> &cameras) |
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{ |
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LOGLN("Estimating rotations..."); |
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int64 t = getTickCount(); |
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const int num_images = static_cast<int>(features.size()); |
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#if 0 |
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// Robustly estimate focal length from rotating cameras |
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vector<Mat> Hs; |
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for (int iter = 0; iter < 100; ++iter) |
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{ |
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int len = 2 + rand()%(pairwise_matches.size() - 1); |
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vector<int> subset; |
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selectRandomSubset(len, pairwise_matches.size(), subset); |
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Hs.clear(); |
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for (size_t i = 0; i < subset.size(); ++i) |
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if (!pairwise_matches[subset[i]].H.empty()) |
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Hs.push_back(pairwise_matches[subset[i]].H); |
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Mat_<double> K; |
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if (Hs.size() >= 2) |
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{ |
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if (calibrateRotatingCamera(Hs, K)) |
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cin.get(); |
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} |
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} |
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#endif |
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// Estimate focal length and set it for all cameras |
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vector<double> focals; |
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estimateFocal(features, pairwise_matches, focals); |
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cameras.resize(num_images); |
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for (int i = 0; i < num_images; ++i) |
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cameras[i].focal = focals[i]; |
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// Restore global motion |
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Graph span_tree; |
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vector<int> span_tree_centers; |
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findMaxSpanningTree(num_images, pairwise_matches, span_tree, span_tree_centers); |
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span_tree.walkBreadthFirst(span_tree_centers[0], CalcRotation(num_images, pairwise_matches, cameras)); |
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LOGLN("Estimating rotations, time: " << ((getTickCount() - t) / getTickFrequency()) << " sec"); |
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} |
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////////////////////////////////////////////////////////////////////////////// |
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void BundleAdjuster::estimate(const vector<ImageFeatures> &features, const vector<MatchesInfo> &pairwise_matches, |
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vector<CameraParams> &cameras) |
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{ |
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if (cost_space_ == NO) |
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return; |
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LOG("Bundle adjustment"); |
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int64 t = getTickCount(); |
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num_images_ = static_cast<int>(features.size()); |
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features_ = &features[0]; |
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pairwise_matches_ = &pairwise_matches[0]; |
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// Prepare focals and rotations |
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cameras_.create(num_images_ * 4, 1, CV_64F); |
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SVD svd; |
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for (int i = 0; i < num_images_; ++i) |
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{ |
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cameras_.at<double>(i * 4, 0) = cameras[i].focal; |
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svd(cameras[i].R, SVD::FULL_UV); |
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Mat R = svd.u * svd.vt; |
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if (determinant(R) < 0) |
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R *= -1; |
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Mat rvec; |
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Rodrigues(R, rvec); CV_Assert(rvec.type() == CV_32F); |
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cameras_.at<double>(i * 4 + 1, 0) = rvec.at<float>(0, 0); |
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cameras_.at<double>(i * 4 + 2, 0) = rvec.at<float>(1, 0); |
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cameras_.at<double>(i * 4 + 3, 0) = rvec.at<float>(2, 0); |
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} |
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// Select only consistent image pairs for futher adjustment |
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edges_.clear(); |
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for (int i = 0; i < num_images_ - 1; ++i) |
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{ |
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for (int j = i + 1; j < num_images_; ++j) |
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{ |
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const MatchesInfo& matches_info = pairwise_matches_[i * num_images_ + j]; |
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if (matches_info.confidence > conf_thresh_) |
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edges_.push_back(make_pair(i, j)); |
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} |
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} |
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// Compute number of correspondences |
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total_num_matches_ = 0; |
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for (size_t i = 0; i < edges_.size(); ++i) |
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total_num_matches_ += static_cast<int>(pairwise_matches[edges_[i].first * num_images_ + edges_[i].second].num_inliers); |
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CvLevMarq solver(num_images_ * 4, total_num_matches_ * 3, |
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cvTermCriteria(CV_TERMCRIT_EPS + CV_TERMCRIT_ITER, 1000, DBL_EPSILON)); |
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CvMat matParams = cameras_; |
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cvCopy(&matParams, solver.param); |
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int count = 0; |
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for(;;) |
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{ |
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const CvMat* _param = 0; |
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CvMat* _J = 0; |
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CvMat* _err = 0; |
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bool proceed = solver.update(_param, _J, _err); |
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cvCopy( _param, &matParams ); |
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if( !proceed || !_err ) |
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break; |
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if( _J ) |
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{ |
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calcJacobian(); |
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CvMat matJ = J_; |
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cvCopy( &matJ, _J ); |
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} |
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if (_err) |
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{ |
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calcError(err_); |
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LOG("."); |
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count++; |
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CvMat matErr = err_; |
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cvCopy( &matErr, _err ); |
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} |
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} |
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LOGLN(""); |
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LOGLN("Bundle adjustment, final error: " << sqrt(err_.dot(err_))); |
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LOGLN("Bundle adjustment, iterations done: " << count); |
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// Obtain global motion |
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for (int i = 0; i < num_images_; ++i) |
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{ |
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cameras[i].focal = cameras_.at<double>(i * 4, 0); |
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Mat rvec(3, 1, CV_64F); |
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rvec.at<double>(0, 0) = cameras_.at<double>(i * 4 + 1, 0); |
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rvec.at<double>(1, 0) = cameras_.at<double>(i * 4 + 2, 0); |
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rvec.at<double>(2, 0) = cameras_.at<double>(i * 4 + 3, 0); |
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Rodrigues(rvec, cameras[i].R); |
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Mat Mf; |
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cameras[i].R.convertTo(Mf, CV_32F); |
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cameras[i].R = Mf; |
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} |
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// Normalize motion to center image |
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Graph span_tree; |
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vector<int> span_tree_centers; |
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findMaxSpanningTree(num_images_, pairwise_matches, span_tree, span_tree_centers); |
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Mat R_inv = cameras[span_tree_centers[0]].R.inv(); |
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for (int i = 0; i < num_images_; ++i) |
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cameras[i].R = R_inv * cameras[i].R; |
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LOGLN("Bundle adjustment, time: " << ((getTickCount() - t) / getTickFrequency()) << " sec"); |
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} |
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void BundleAdjuster::calcError(Mat &err) |
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{ |
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err.create(total_num_matches_ * 3, 1, CV_64F); |
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int match_idx = 0; |
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for (size_t edge_idx = 0; edge_idx < edges_.size(); ++edge_idx) |
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{ |
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int i = edges_[edge_idx].first; |
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int j = edges_[edge_idx].second; |
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double f1 = cameras_.at<double>(i * 4, 0); |
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double f2 = cameras_.at<double>(j * 4, 0); |
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double R1[9], R2[9]; |
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Mat R1_(3, 3, CV_64F, R1), R2_(3, 3, CV_64F, R2); |
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Mat rvec(3, 1, CV_64F); |
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rvec.at<double>(0, 0) = cameras_.at<double>(i * 4 + 1, 0); |
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rvec.at<double>(1, 0) = cameras_.at<double>(i * 4 + 2, 0); |
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rvec.at<double>(2, 0) = cameras_.at<double>(i * 4 + 3, 0); |
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Rodrigues(rvec, R1_); CV_Assert(R1_.type() == CV_64F); |
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rvec.at<double>(0, 0) = cameras_.at<double>(j * 4 + 1, 0); |
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rvec.at<double>(1, 0) = cameras_.at<double>(j * 4 + 2, 0); |
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rvec.at<double>(2, 0) = cameras_.at<double>(j * 4 + 3, 0); |
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Rodrigues(rvec, R2_); CV_Assert(R2_.type() == CV_64F); |
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const ImageFeatures& features1 = features_[i]; |
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const ImageFeatures& features2 = features_[j]; |
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const MatchesInfo& matches_info = pairwise_matches_[i * num_images_ + j]; |
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for (size_t k = 0; k < matches_info.matches.size(); ++k) |
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{ |
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if (!matches_info.inliers_mask[k]) |
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continue; |
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const DMatch& m = matches_info.matches[k]; |
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Point2d kp1 = features1.keypoints[m.queryIdx].pt; |
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kp1.x -= 0.5 * features1.img_size.width; |
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kp1.y -= 0.5 * features1.img_size.height; |
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Point2d kp2 = features2.keypoints[m.trainIdx].pt; |
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kp2.x -= 0.5 * features2.img_size.width; |
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kp2.y -= 0.5 * features2.img_size.height; |
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double len1 = sqrt(kp1.x * kp1.x + kp1.y * kp1.y + f1 * f1); |
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double len2 = sqrt(kp2.x * kp2.x + kp2.y * kp2.y + f2 * f2); |
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Point3d p1(kp1.x / len1, kp1.y / len1, f1 / len1); |
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Point3d p2(kp2.x / len2, kp2.y / len2, f2 / len2); |
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Point3d d1(p1.x * R1[0] + p1.y * R1[1] + p1.z * R1[2], |
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p1.x * R1[3] + p1.y * R1[4] + p1.z * R1[5], |
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p1.x * R1[6] + p1.y * R1[7] + p1.z * R1[8]); |
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Point3d d2(p2.x * R2[0] + p2.y * R2[1] + p2.z * R2[2], |
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p2.x * R2[3] + p2.y * R2[4] + p2.z * R2[5], |
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p2.x * R2[6] + p2.y * R2[7] + p2.z * R2[8]); |
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double mult = 1; // For cost_space_ == RAY_SPACE |
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if (cost_space_ == FOCAL_RAY_SPACE) |
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mult = sqrt(f1 * f2); |
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err.at<double>(3 * match_idx, 0) = mult * (d1.x - d2.x); |
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err.at<double>(3 * match_idx + 1, 0) = mult * (d1.y - d2.y); |
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err.at<double>(3 * match_idx + 2, 0) = mult * (d1.z - d2.z); |
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match_idx++; |
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} |
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} |
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} |
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void calcDeriv(const Mat &err1, const Mat &err2, double h, Mat res) |
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{ |
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for (int i = 0; i < err1.rows; ++i) |
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res.at<double>(i, 0) = (err2.at<double>(i, 0) - err1.at<double>(i, 0)) / h; |
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} |
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void BundleAdjuster::calcJacobian() |
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{ |
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J_.create(total_num_matches_ * 3, num_images_ * 4, CV_64F); |
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double f, r; |
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const double df = 0.001; // Focal length step |
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const double dr = 0.001; // Angle step |
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for (int i = 0; i < num_images_; ++i) |
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{ |
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f = cameras_.at<double>(i * 4, 0); |
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cameras_.at<double>(i * 4, 0) = f - df; |
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calcError(err1_); |
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cameras_.at<double>(i * 4, 0) = f + df; |
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calcError(err2_); |
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calcDeriv(err1_, err2_, 2 * df, J_.col(i * 4)); |
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cameras_.at<double>(i * 4, 0) = f; |
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r = cameras_.at<double>(i * 4 + 1, 0); |
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cameras_.at<double>(i * 4 + 1, 0) = r - dr; |
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calcError(err1_); |
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cameras_.at<double>(i * 4 + 1, 0) = r + dr; |
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calcError(err2_); |
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calcDeriv(err1_, err2_, 2 * dr, J_.col(i * 4 + 1)); |
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cameras_.at<double>(i * 4 + 1, 0) = r; |
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r = cameras_.at<double>(i * 4 + 2, 0); |
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cameras_.at<double>(i * 4 + 2, 0) = r - dr; |
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calcError(err1_); |
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cameras_.at<double>(i * 4 + 2, 0) = r + dr; |
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calcError(err2_); |
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calcDeriv(err1_, err2_, 2 * dr, J_.col(i * 4 + 2)); |
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cameras_.at<double>(i * 4 + 2, 0) = r; |
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r = cameras_.at<double>(i * 4 + 3, 0); |
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cameras_.at<double>(i * 4 + 3, 0) = r - dr; |
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calcError(err1_); |
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cameras_.at<double>(i * 4 + 3, 0) = r + dr; |
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calcError(err2_); |
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calcDeriv(err1_, err2_, 2 * dr, J_.col(i * 4 + 3)); |
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cameras_.at<double>(i * 4 + 3, 0) = r; |
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} |
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} |
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////////////////////////////////////////////////////////////////////////////// |
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void waveCorrect(vector<Mat> &rmats) |
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{ |
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LOGLN("Wave correcting..."); |
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int64 t = getTickCount(); |
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float data[9]; |
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Mat r0(1, 3, CV_32F, data); |
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Mat r1(1, 3, CV_32F, data + 3); |
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Mat r2(1, 3, CV_32F, data + 6); |
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Mat R(3, 3, CV_32F, data); |
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Mat cov = Mat::zeros(3, 3, CV_32F); |
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for (size_t i = 0; i < rmats.size(); ++i) |
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{ |
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Mat r0 = rmats[i].col(0); |
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cov += r0 * r0.t(); |
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} |
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SVD svd; |
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svd(cov, SVD::FULL_UV); |
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svd.vt.row(2).copyTo(r1); |
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if (determinant(svd.vt) < 0) r1 *= -1; |
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Mat avgz = Mat::zeros(3, 1, CV_32F); |
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for (size_t i = 0; i < rmats.size(); ++i) |
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avgz += rmats[i].col(2); |
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r1.cross(avgz.t()).copyTo(r0); |
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normalize(r0, r0); |
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r1.cross(r0).copyTo(r2); |
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if (determinant(R) < 0) R *= -1; |
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for (size_t i = 0; i < rmats.size(); ++i) |
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rmats[i] = R * rmats[i]; |
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LOGLN("Wave correcting, time: " << ((getTickCount() - t) / getTickFrequency()) << " sec"); |
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} |
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////////////////////////////////////////////////////////////////////////////// |
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string matchesGraphAsString(vector<string> &pathes, vector<MatchesInfo> &pairwise_matches, |
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float conf_threshold) |
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{ |
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stringstream str; |
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str << "graph matches_graph{\n"; |
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const int num_images = static_cast<int>(pathes.size()); |
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set<pair<int,int> > span_tree_edges; |
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DisjointSets comps(num_images); |
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for (int i = 0; i < num_images; ++i) |
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{ |
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for (int j = 0; j < num_images; ++j) |
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{ |
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if (pairwise_matches[i*num_images + j].confidence < conf_threshold) |
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continue; |
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int comp1 = comps.findSetByElem(i); |
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int comp2 = comps.findSetByElem(j); |
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if (comp1 != comp2) |
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{ |
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comps.mergeSets(comp1, comp2); |
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span_tree_edges.insert(make_pair(i, j)); |
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} |
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} |
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} |
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for (set<pair<int,int> >::const_iterator itr = span_tree_edges.begin(); |
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itr != span_tree_edges.end(); ++itr) |
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{ |
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pair<int,int> edge = *itr; |
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if (span_tree_edges.find(edge) != span_tree_edges.end()) |
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{ |
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string name_src = pathes[edge.first]; |
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size_t prefix_len = name_src.find_last_of("/\\"); |
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if (prefix_len != string::npos) prefix_len++; else prefix_len = 0; |
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name_src = name_src.substr(prefix_len, name_src.size() - prefix_len); |
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string name_dst = pathes[edge.second]; |
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prefix_len = name_dst.find_last_of("/\\"); |
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if (prefix_len != string::npos) prefix_len++; else prefix_len = 0; |
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name_dst = name_dst.substr(prefix_len, name_dst.size() - prefix_len); |
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int pos = edge.first*num_images + edge.second; |
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str << "\"" << name_src << "\" -- \"" << name_dst << "\"" |
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<< "[label=\"Nm=" << pairwise_matches[pos].matches.size() |
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<< ", Ni=" << pairwise_matches[pos].num_inliers |
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<< ", C=" << pairwise_matches[pos].confidence << "\"];\n"; |
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} |
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} |
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for (size_t i = 0; i < comps.size.size(); ++i) |
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{ |
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if (comps.size[comps.findSetByElem(i)] == 1) |
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{ |
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string name = pathes[i]; |
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size_t prefix_len = name.find_last_of("/\\"); |
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if (prefix_len != string::npos) prefix_len++; else prefix_len = 0; |
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name = name.substr(prefix_len, name.size() - prefix_len); |
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str << "\"" << name << "\";\n"; |
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} |
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} |
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str << "}"; |
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return str.str(); |
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} |
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vector<int> leaveBiggestComponent(vector<ImageFeatures> &features, vector<MatchesInfo> &pairwise_matches, |
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float conf_threshold) |
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{ |
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const int num_images = static_cast<int>(features.size()); |
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DisjointSets comps(num_images); |
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for (int i = 0; i < num_images; ++i) |
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{ |
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for (int j = 0; j < num_images; ++j) |
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{ |
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if (pairwise_matches[i*num_images + j].confidence < conf_threshold) |
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continue; |
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int comp1 = comps.findSetByElem(i); |
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int comp2 = comps.findSetByElem(j); |
|
if (comp1 != comp2) |
|
comps.mergeSets(comp1, comp2); |
|
} |
|
} |
|
|
|
int max_comp = static_cast<int>(max_element(comps.size.begin(), comps.size.end()) - comps.size.begin()); |
|
|
|
vector<int> indices; |
|
vector<int> indices_removed; |
|
for (int i = 0; i < num_images; ++i) |
|
if (comps.findSetByElem(i) == max_comp) |
|
indices.push_back(i); |
|
else |
|
indices_removed.push_back(i); |
|
|
|
vector<ImageFeatures> features_subset; |
|
vector<MatchesInfo> pairwise_matches_subset; |
|
for (size_t i = 0; i < indices.size(); ++i) |
|
{ |
|
features_subset.push_back(features[indices[i]]); |
|
for (size_t j = 0; j < indices.size(); ++j) |
|
{ |
|
pairwise_matches_subset.push_back(pairwise_matches[indices[i]*num_images + indices[j]]); |
|
pairwise_matches_subset.back().src_img_idx = static_cast<int>(i); |
|
pairwise_matches_subset.back().dst_img_idx = static_cast<int>(j); |
|
} |
|
} |
|
|
|
if (static_cast<int>(features_subset.size()) == num_images) |
|
return indices; |
|
|
|
LOG("Removed some images, because can't match them: ("); |
|
LOG(indices_removed[0]+1); |
|
for (size_t i = 1; i < indices_removed.size(); ++i) |
|
LOG(", " << indices_removed[i]+1); |
|
LOGLN("). Try decrease --match_conf value."); |
|
|
|
features = features_subset; |
|
pairwise_matches = pairwise_matches_subset; |
|
|
|
return indices; |
|
} |
|
|
|
|
|
void findMaxSpanningTree(int num_images, const vector<MatchesInfo> &pairwise_matches, |
|
Graph &span_tree, vector<int> ¢ers) |
|
{ |
|
Graph graph(num_images); |
|
vector<GraphEdge> edges; |
|
|
|
// Construct images graph and remember its edges |
|
for (int i = 0; i < num_images; ++i) |
|
{ |
|
for (int j = 0; j < num_images; ++j) |
|
{ |
|
if (pairwise_matches[i * num_images + j].H.empty()) |
|
continue; |
|
float conf = static_cast<float>(pairwise_matches[i * num_images + j].num_inliers); |
|
graph.addEdge(i, j, conf); |
|
edges.push_back(GraphEdge(i, j, conf)); |
|
} |
|
} |
|
|
|
DisjointSets comps(num_images); |
|
span_tree.create(num_images); |
|
vector<int> span_tree_powers(num_images, 0); |
|
|
|
// Find maximum spanning tree |
|
sort(edges.begin(), edges.end(), greater<GraphEdge>()); |
|
for (size_t i = 0; i < edges.size(); ++i) |
|
{ |
|
int comp1 = comps.findSetByElem(edges[i].from); |
|
int comp2 = comps.findSetByElem(edges[i].to); |
|
if (comp1 != comp2) |
|
{ |
|
comps.mergeSets(comp1, comp2); |
|
span_tree.addEdge(edges[i].from, edges[i].to, edges[i].weight); |
|
span_tree.addEdge(edges[i].to, edges[i].from, edges[i].weight); |
|
span_tree_powers[edges[i].from]++; |
|
span_tree_powers[edges[i].to]++; |
|
} |
|
} |
|
|
|
// Find spanning tree leafs |
|
vector<int> span_tree_leafs; |
|
for (int i = 0; i < num_images; ++i) |
|
if (span_tree_powers[i] == 1) |
|
span_tree_leafs.push_back(i); |
|
|
|
// Find maximum distance from each spanning tree vertex |
|
vector<int> max_dists(num_images, 0); |
|
vector<int> cur_dists; |
|
for (size_t i = 0; i < span_tree_leafs.size(); ++i) |
|
{ |
|
cur_dists.assign(num_images, 0); |
|
span_tree.walkBreadthFirst(span_tree_leafs[i], IncDistance(cur_dists)); |
|
for (int j = 0; j < num_images; ++j) |
|
max_dists[j] = max(max_dists[j], cur_dists[j]); |
|
} |
|
|
|
// Find min-max distance |
|
int min_max_dist = max_dists[0]; |
|
for (int i = 1; i < num_images; ++i) |
|
if (min_max_dist > max_dists[i]) |
|
min_max_dist = max_dists[i]; |
|
|
|
// Find spanning tree centers |
|
centers.clear(); |
|
for (int i = 0; i < num_images; ++i) |
|
if (max_dists[i] == min_max_dist) |
|
centers.push_back(i); |
|
CV_Assert(centers.size() > 0 && centers.size() <= 2); |
|
}
|
|
|