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: sameeragarwal (at) google.com (Sameer Agarwal) 30 // 31 // Templated struct implementing the camera model and residual 32 // computation for bundle adjustment used by Noah Snavely's Bundler 33 // SfM system. This is also the camera model/residual for the bundle 34 // adjustment problems in the BAL dataset. It is templated so that we 35 // can use Ceres's automatic differentiation to compute analytic 36 // jacobians. 37 // 38 // For details see: http://phototour.cs.washington.edu/bundler/ 39 // and http://grail.cs.washington.edu/projects/bal/ 40 41 #ifndef CERES_EXAMPLES_SNAVELY_REPROJECTION_ERROR_H_ 42 #define CERES_EXAMPLES_SNAVELY_REPROJECTION_ERROR_H_ 43 44 #include "ceres/rotation.h" 45 46 namespace ceres { 47 namespace examples { 48 49 // Templated pinhole camera model for used with Ceres. The camera is 50 // parameterized using 9 parameters: 3 for rotation, 3 for translation, 1 for 51 // focal length and 2 for radial distortion. The principal point is not modeled 52 // (i.e. it is assumed be located at the image center). 53 struct SnavelyReprojectionError { 54 SnavelyReprojectionError(double observed_x, double observed_y) 55 : observed_x(observed_x), observed_y(observed_y) {} 56 57 template <typename T> 58 bool operator()(const T* const camera, 59 const T* const point, 60 T* residuals) const { 61 // camera[0,1,2] are the angle-axis rotation. 62 T p[3]; 63 ceres::AngleAxisRotatePoint(camera, point, p); 64 65 // camera[3,4,5] are the translation. 66 p[0] += camera[3]; 67 p[1] += camera[4]; 68 p[2] += camera[5]; 69 70 // Compute the center of distortion. The sign change comes from 71 // the camera model that Noah Snavely's Bundler assumes, whereby 72 // the camera coordinate system has a negative z axis. 73 const T& focal = camera[6]; 74 T xp = - p[0] / p[2]; 75 T yp = - p[1] / p[2]; 76 77 // Apply second and fourth order radial distortion. 78 const T& l1 = camera[7]; 79 const T& l2 = camera[8]; 80 T r2 = xp*xp + yp*yp; 81 T distortion = T(1.0) + r2 * (l1 + l2 * r2); 82 83 // Compute final projected point position. 84 T predicted_x = focal * distortion * xp; 85 T predicted_y = focal * distortion * yp; 86 87 // The error is the difference between the predicted and observed position. 88 residuals[0] = predicted_x - T(observed_x); 89 residuals[1] = predicted_y - T(observed_y); 90 91 return true; 92 } 93 94 double observed_x; 95 double observed_y; 96 }; 97 98 // Templated pinhole camera model for used with Ceres. The camera is 99 // parameterized using 10 parameters. 4 for rotation, 3 for 100 // translation, 1 for focal length and 2 for radial distortion. The 101 // principal point is not modeled (i.e. it is assumed be located at 102 // the image center). 103 struct SnavelyReprojectionErrorWithQuaternions { 104 // (u, v): the position of the observation with respect to the image 105 // center point. 106 SnavelyReprojectionErrorWithQuaternions(double observed_x, double observed_y) 107 : observed_x(observed_x), observed_y(observed_y) {} 108 109 template <typename T> 110 bool operator()(const T* const camera_rotation, 111 const T* const camera_translation_and_intrinsics, 112 const T* const point, 113 T* residuals) const { 114 const T& focal = camera_translation_and_intrinsics[3]; 115 const T& l1 = camera_translation_and_intrinsics[4]; 116 const T& l2 = camera_translation_and_intrinsics[5]; 117 118 // Use a quaternion rotation that doesn't assume the quaternion is 119 // normalized, since one of the ways to run the bundler is to let Ceres 120 // optimize all 4 quaternion parameters unconstrained. 121 T p[3]; 122 QuaternionRotatePoint(camera_rotation, point, p); 123 124 p[0] += camera_translation_and_intrinsics[0]; 125 p[1] += camera_translation_and_intrinsics[1]; 126 p[2] += camera_translation_and_intrinsics[2]; 127 128 // Compute the center of distortion. The sign change comes from 129 // the camera model that Noah Snavely's Bundler assumes, whereby 130 // the camera coordinate system has a negative z axis. 131 T xp = - p[0] / p[2]; 132 T yp = - p[1] / p[2]; 133 134 // Apply second and fourth order radial distortion. 135 T r2 = xp*xp + yp*yp; 136 T distortion = T(1.0) + r2 * (l1 + l2 * r2); 137 138 // Compute final projected point position. 139 T predicted_x = focal * distortion * xp; 140 T predicted_y = focal * distortion * yp; 141 142 // The error is the difference between the predicted and observed position. 143 residuals[0] = predicted_x - T(observed_x); 144 residuals[1] = predicted_y - T(observed_y); 145 146 return true; 147 } 148 149 double observed_x; 150 double observed_y; 151 }; 152 153 } // namespace examples 154 } // namespace ceres 155 156 #endif // CERES_EXAMPLES_SNAVELY_REPROJECTION_ERROR_H_ 157
