|  | // Ceres Solver - A fast non-linear least squares minimizer | 
|  | // Copyright 2015 Google Inc. All rights reserved. | 
|  | // http://ceres-solver.org/ | 
|  | // | 
|  | // Redistribution and use in source and binary forms, with or without | 
|  | // modification, are permitted provided that the following conditions are met: | 
|  | // | 
|  | // * Redistributions of source code must retain the above copyright notice, | 
|  | //   this list of conditions and the following disclaimer. | 
|  | // * Redistributions in binary form must reproduce the above copyright notice, | 
|  | //   this list of conditions and the following disclaimer in the documentation | 
|  | //   and/or other materials provided with the distribution. | 
|  | // * Neither the name of Google Inc. nor the names of its contributors may be | 
|  | //   used to endorse or promote products derived from this software without | 
|  | //   specific prior written permission. | 
|  | // | 
|  | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | 
|  | // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | 
|  | // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | 
|  | // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE | 
|  | // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | 
|  | // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | 
|  | // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | 
|  | // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | 
|  | // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | 
|  | // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | 
|  | // POSSIBILITY OF SUCH DAMAGE. | 
|  | // | 
|  | // Author: sameeragarwal@google.com (Sameer Agarwal) | 
|  | // | 
|  | // Templated struct implementing the camera model and residual | 
|  | // computation for bundle adjustment used by Noah Snavely's Bundler | 
|  | // SfM system. This is also the camera model/residual for the bundle | 
|  | // adjustment problems in the BAL dataset. It is templated so that we | 
|  | // can use Ceres's automatic differentiation to compute analytic | 
|  | // jacobians. | 
|  | // | 
|  | // For details see: http://phototour.cs.washington.edu/bundler/ | 
|  | // and http://grail.cs.washington.edu/projects/bal/ | 
|  |  | 
|  | #ifndef CERES_EXAMPLES_SNAVELY_REPROJECTION_ERROR_H_ | 
|  | #define CERES_EXAMPLES_SNAVELY_REPROJECTION_ERROR_H_ | 
|  |  | 
|  | #include "ceres/rotation.h" | 
|  |  | 
|  | namespace ceres { | 
|  | namespace examples { | 
|  |  | 
|  | // Templated pinhole camera model for used with Ceres.  The camera is | 
|  | // parameterized using 9 parameters: 3 for rotation, 3 for translation, 1 for | 
|  | // focal length and 2 for radial distortion. The principal point is not modeled | 
|  | // (i.e. it is assumed be located at the image center). | 
|  | struct SnavelyReprojectionError { | 
|  | SnavelyReprojectionError(double observed_x, double observed_y) | 
|  | : observed_x(observed_x), observed_y(observed_y) {} | 
|  |  | 
|  | template <typename T> | 
|  | bool operator()(const T* const camera, | 
|  | const T* const point, | 
|  | T* residuals) const { | 
|  | // camera[0,1,2] are the angle-axis rotation. | 
|  | T p[3]; | 
|  | AngleAxisRotatePoint(camera, point, p); | 
|  |  | 
|  | // camera[3,4,5] are the translation. | 
|  | p[0] += camera[3]; | 
|  | p[1] += camera[4]; | 
|  | p[2] += camera[5]; | 
|  |  | 
|  | // Compute the center of distortion. The sign change comes from | 
|  | // the camera model that Noah Snavely's Bundler assumes, whereby | 
|  | // the camera coordinate system has a negative z axis. | 
|  | const T xp = - p[0] / p[2]; | 
|  | const T yp = - p[1] / p[2]; | 
|  |  | 
|  | // Apply second and fourth order radial distortion. | 
|  | const T& l1 = camera[7]; | 
|  | const T& l2 = camera[8]; | 
|  | const T r2 = xp*xp + yp*yp; | 
|  | const T distortion = 1.0 + r2  * (l1 + l2  * r2); | 
|  |  | 
|  |  | 
|  | // Compute final projected point position. | 
|  | const T& focal = camera[6]; | 
|  | const T predicted_x = focal * distortion * xp; | 
|  | const T predicted_y = focal * distortion * yp; | 
|  |  | 
|  | // The error is the difference between the predicted and observed position. | 
|  | residuals[0] = predicted_x - observed_x; | 
|  | residuals[1] = predicted_y - observed_y; | 
|  |  | 
|  | return true; | 
|  | } | 
|  |  | 
|  | // Factory to hide the construction of the CostFunction object from | 
|  | // the client code. | 
|  | static ceres::CostFunction* Create(const double observed_x, | 
|  | const double observed_y) { | 
|  | return (new ceres::AutoDiffCostFunction<SnavelyReprojectionError, 2, 9, 3>( | 
|  | new SnavelyReprojectionError(observed_x, observed_y))); | 
|  | } | 
|  |  | 
|  | double observed_x; | 
|  | double observed_y; | 
|  | }; | 
|  |  | 
|  | // Templated pinhole camera model for used with Ceres.  The camera is | 
|  | // parameterized using 10 parameters. 4 for rotation, 3 for | 
|  | // translation, 1 for focal length and 2 for radial distortion. The | 
|  | // principal point is not modeled (i.e. it is assumed be located at | 
|  | // the image center). | 
|  | struct SnavelyReprojectionErrorWithQuaternions { | 
|  | // (u, v): the position of the observation with respect to the image | 
|  | // center point. | 
|  | SnavelyReprojectionErrorWithQuaternions(double observed_x, double observed_y) | 
|  | : observed_x(observed_x), observed_y(observed_y) {} | 
|  |  | 
|  | template <typename T> | 
|  | bool operator()(const T* const camera, | 
|  | const T* const point, | 
|  | T* residuals) const { | 
|  | // camera[0,1,2,3] is are the rotation of the camera as a quaternion. | 
|  | // | 
|  | // We use QuaternionRotatePoint as it does not assume that the | 
|  | // quaternion is normalized, since one of the ways to run the | 
|  | // bundle adjuster is to let Ceres optimize all 4 quaternion | 
|  | // parameters without a local parameterization. | 
|  | T p[3]; | 
|  | QuaternionRotatePoint(camera, point, p); | 
|  |  | 
|  | p[0] += camera[4]; | 
|  | p[1] += camera[5]; | 
|  | p[2] += camera[6]; | 
|  |  | 
|  | // Compute the center of distortion. The sign change comes from | 
|  | // the camera model that Noah Snavely's Bundler assumes, whereby | 
|  | // the camera coordinate system has a negative z axis. | 
|  | const T xp = - p[0] / p[2]; | 
|  | const T yp = - p[1] / p[2]; | 
|  |  | 
|  | // Apply second and fourth order radial distortion. | 
|  | const T& l1 = camera[8]; | 
|  | const T& l2 = camera[9]; | 
|  |  | 
|  | const T r2 = xp*xp + yp*yp; | 
|  | const T distortion = 1.0 + r2  * (l1 + l2  * r2); | 
|  |  | 
|  | // Compute final projected point position. | 
|  | const T& focal = camera[7]; | 
|  | const T predicted_x = focal * distortion * xp; | 
|  | const T predicted_y = focal * distortion * yp; | 
|  |  | 
|  | // The error is the difference between the predicted and observed position. | 
|  | residuals[0] = predicted_x - observed_x; | 
|  | residuals[1] = predicted_y - observed_y; | 
|  |  | 
|  | return true; | 
|  | } | 
|  |  | 
|  | // Factory to hide the construction of the CostFunction object from | 
|  | // the client code. | 
|  | static ceres::CostFunction* Create(const double observed_x, | 
|  | const double observed_y) { | 
|  | return (new ceres::AutoDiffCostFunction< | 
|  | SnavelyReprojectionErrorWithQuaternions, 2, 10, 3>( | 
|  | new SnavelyReprojectionErrorWithQuaternions(observed_x, | 
|  | observed_y))); | 
|  | } | 
|  |  | 
|  | double observed_x; | 
|  | double observed_y; | 
|  | }; | 
|  |  | 
|  | }  // namespace examples | 
|  | }  // namespace ceres | 
|  |  | 
|  | #endif  // CERES_EXAMPLES_SNAVELY_REPROJECTION_ERROR_H_ |