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