Estimates a 3D similarity transformation from two point sets. More...
#include <EstimateSimilarityTransformation3D.hpp>
Public Types | |
typedef super::VectorXT | VectorXT |
Column vector of arbitrary size with value type T. | |
typedef super::MatrixXT | MatrixXT |
Matrix of arbitrary size with value type T. | |
typedef super::Vector2T | Vector2T |
2D column vector with value type T. | |
typedef super::Vector3T | Vector3T |
3D column vector with value type T. | |
typedef super::Vector4T | Vector4T |
4D column vector with value type T. | |
typedef super::RowVector2T | RowVector2T |
2D row vector with value type T. | |
typedef super::RowVector3T | RowVector3T |
3D row vector with value type T. | |
typedef super::Matrix2T | Matrix2T |
2 x 2 matrix with value type T. | |
typedef super::Matrix3T | Matrix3T |
3 x 3 matrix with value type T. | |
typedef super::Matrix4T | Matrix4T |
4 x 4 matrix with value type T. | |
typedef super::ArrayXT | ArrayXT |
General-purpose array of arbitrary size with value type T. | |
enum | Error { NOT_ENOUGH_POINTS, UNEQUAL_NUMBER_OF_POINTS, UNKNOWN_ERROR, WRONG_POINT_SIZE } |
Public Member Functions | |
EstimateSimilarityTransformation3D () | |
Constructs a new instance of this class. | |
EstimateSimilarityTransformation3D (const std::vector< Coordinate< T > > &source_points, const std::vector< Coordinate< T > > &target_points) | |
Constructs a new instance of this class. | |
EstimateSimilarityTransformation3D (const std::vector< Vector3T > &source_points, const std::vector< Vector3T > &target_points) | |
Constructs a new instance of this class. | |
EstimateSimilarityTransformation3D (const std::vector< Vector4T, Eigen::aligned_allocator< Vector4T > > &source_points, const std::vector< Vector4T, Eigen::aligned_allocator< Vector4T > > &target_points) | |
Constructs a new instance of this class. | |
virtual | ~EstimateSimilarityTransformation3D () |
Deletes the instance. | |
virtual void | compute () |
Computes the transformation estimation. | |
Matrix3T | getRotationMatrix () const |
Vector3T | getTranslationVector () const |
value_type | getScalingFactor () const |
virtual value_type | getRMS () const |
Returns the root mean square (RMS) error of the estimated transformation. | |
virtual const Matrix4T & | getTransformationMatrix () const |
void | setSourcePoints (const std::vector< Coordinate< T > > &) |
Sets the source points. | |
void | setSourcePoints (const std::vector< Vector3T > &) |
Sets the source points. | |
void | setSourcePoints (const std::vector< Vector4T, Eigen::aligned_allocator< Vector4T > > &) |
Sets the source points. | |
void | setTargetPoints (const std::vector< Coordinate< T > > &) |
Sets the target points. | |
void | setTargetPoints (const std::vector< Vector3T > &) |
Sets the target points. | |
void | setTargetPoints (const std::vector< Vector4T, Eigen::aligned_allocator< Vector4T > > &) |
Sets the target points. | |
Public Attributes | |
EIGEN_MAKE_ALIGNED_OPERATOR_NEW typedef T | value_type |
Internally used value type (should be a floating point type). | |
Protected Attributes | |
MatrixXT | m_source_points |
MatrixXT | m_target_points |
Matrix4T | m_transformation_matrix |
Estimates a 3D similarity transformation from two point sets.
This class estimates a 3D similarity transformation between two point sets in terms of least squares. The point sets must have the same cardinality, and the points must correspond to each other. There must be at least two corresponding point pairs.
The algorithm estimates a transformation matrix as shown below:
\[ \begin{pmatrix} y_1 \\ y_2 \\ y_3 \\ 1 \end{pmatrix} = \begin{pmatrix} r_{11} & r_{12} & r_{13} & b_1 \\ r_{21} & r_{22} & r_{23} & b_2 \\ r_{31} & r_{32} & r_{33} & b_3 \\ 0 & 0 & 0 & 1 \end{pmatrix} \begin{pmatrix} x_1 \\ x_2 \\ x_3 \\ 1 \end{pmatrix} \qquad \qquad \text{or} \qquad \qquad y = Rx + b \quad \wedge \quad RR^T = \alpha^2 I \]
The source points are the set of all \( x \) and the target points are the set of all \( y \).
Here is an more elaborate example to see, how to use the class:
#include <iostream> #include <vector> #include <TRTK/Coordinate.hpp> #include <TRTK/Transform3D.hpp> #include <TRTK/EstimateSimilarityTransformation3D.hpp> using std::cout; using std::endl; using std::vector; using namespace TRTK; int main() { // Construct a transformation which rotates 90 degrees counter-clockwise // in the x-y plane with a center of rotation of (1, 3, 0) and a uniform // scaling of 2. Transform3D<double> transform; const double pi = Transform3D<double>::pi; transform.translate(-1, -3, 0).rotateZ(pi/2).scale(2, 2, 2).translate(1, 3, 0); // Construct two sets with source and target points, respectively. vector<Coordinate<double> > source_points; vector<Coordinate<double> > target_points; Coordinate<double> source_point1( 1, 2, 0); Coordinate<double> source_point2( 3, -2, 0); Coordinate<double> source_point3(-1, 1, 1); Coordinate<double> source_point4( 2, 0, -1); source_points.push_back(source_point1); source_points.push_back(source_point2); source_points.push_back(source_point3); source_points.push_back(source_point4); Coordinate<double> target_point1 = transform * source_point1; Coordinate<double> target_point2 = transform * source_point2; Coordinate<double> target_point3 = transform * source_point3; Coordinate<double> target_point4 = transform * source_point4; target_points.push_back(target_point1); target_points.push_back(target_point2); target_points.push_back(target_point3); target_points.push_back(target_point4); // Perform the transformation estimation. EstimateSimilarityTransformation3D<double> estimateSimilarityTransformation3D(source_points, target_points); estimateSimilarityTransformation3D.compute(); // Display the results. cout.precision(4); cout << std::fixed; cout << "Original transformation matrix:" << endl << endl << transform.getTransformationMatrix() << endl << endl; cout << "Estimated transformation matrix:" << endl << endl << estimateSimilarityTransformation3D.getTransformationMatrix() << endl << endl; // Example of how to use the result. Transform3D<double> transform2 = estimateSimilarityTransformation3D.getTransformationMatrix(); cout << "Source point 1: " << source_point1 << endl << "Target point 1: " << target_point1 << endl << "Target point 1: " << transform2 * source_point1 << endl; return 0; }
Output:
Original transformation matrix: 0.0000 -2.0000 0.0000 7.0000 2.0000 0.0000 0.0000 1.0000 0.0000 0.0000 2.0000 0.0000 0.0000 0.0000 0.0000 1.0000 Estimated transformation matrix: -0.0000 -2.0000 -0.0000 7.0000 2.0000 0.0000 -0.0000 1.0000 -0.0000 0.0000 2.0000 0.0000 0.0000 0.0000 0.0000 1.0000 Source point 1: (1.0000, 2.0000, 0.0000) Target point 1: (3.0000, 3.0000, 0.0000) Target point 1: (3.0000, 3.0000, 0.0000)
Definition at line 205 of file EstimateSimilarityTransformation3D.hpp.
enum TRTK::EstimateTransformation::Error [inherited] |
Definition at line 62 of file EstimateTransformation.hpp.
TRTK::EstimateSimilarityTransformation3D< T >::EstimateSimilarityTransformation3D | ( | ) |
Constructs a new instance of this class.
T | scalar type of the coordinates |
Definition at line 264 of file EstimateSimilarityTransformation3D.hpp.
TRTK::EstimateSimilarityTransformation3D< T >::EstimateSimilarityTransformation3D | ( | const std::vector< Coordinate< T > > & | source_points, |
const std::vector< Coordinate< T > > & | target_points | ||
) |
Constructs a new instance of this class.
T | scalar type of the coordinates |
[in] | source_points | The points can either be plain 3D or 4D homogeneous coordinates. |
[in] | target_points | The points can either be plain 3D or 4D homogeneous coordinates. |
No transformation estimation is done. To do so, please call compute().
ErrorObj | If there are any coordinates other than 3D or 4D coordinates, an error object is thrown and its error code is set to WRONG_POINT_SIZE . |
Definition at line 291 of file EstimateSimilarityTransformation3D.hpp.
TRTK::EstimateSimilarityTransformation3D< T >::EstimateSimilarityTransformation3D | ( | const std::vector< Vector3T > & | source_points, |
const std::vector< Vector3T > & | target_points | ||
) |
Constructs a new instance of this class.
T | scalar type of the coordinates |
[in] | source_points | 3D coordinates. |
[in] | target_points | 3D coordinates. |
No transformation estimation is done. To do so, please call compute().
Definition at line 314 of file EstimateSimilarityTransformation3D.hpp.
TRTK::EstimateSimilarityTransformation3D< T >::EstimateSimilarityTransformation3D | ( | const std::vector< Vector4T, Eigen::aligned_allocator< Vector4T > > & | source_points, |
const std::vector< Vector4T, Eigen::aligned_allocator< Vector4T > > & | target_points | ||
) |
Constructs a new instance of this class.
T | scalar type of the coordinates |
[in] | source_points | 4D homogeneous coordinates. |
[in] | target_points | 4D homogeneous coordinates. |
No transformation estimation is done. To do so, please call compute().
Definition at line 337 of file EstimateSimilarityTransformation3D.hpp.
TRTK::EstimateSimilarityTransformation3D< T >::~EstimateSimilarityTransformation3D | ( | ) | [virtual] |
Deletes the instance.
T | scalar type of the coordinates |
Definition at line 352 of file EstimateSimilarityTransformation3D.hpp.
void TRTK::EstimateSimilarityTransformation3D< T >::compute | ( | ) | [virtual] |
Computes the transformation estimation.
T | scalar type of the coordinates |
The transformation estimation is a least square scheme which decomposes a correlation matrix between the two point sets using the singular value decomposition. For a more detailed explanation of the algorithm, please have a look at the source code. (A link should be below.)
The direction of the transformation is from the source points to the target points: \( p_{target} = \cal{T} \; \{ p_{source} \} \).
ErrorObj | If the point sets do not have the same cardinality, an error object is thrown and its error code is set to UNEQUAL_NUMBER_OF_POINTS . |
ErrorObj | If there are not enough points (at least two) to perform the transformation estimation, an error object is thrown and its error code is set to NOT_ENOUGH_POINTS . |
Implements TRTK::EstimateTransformation3D< T >.
Definition at line 379 of file EstimateSimilarityTransformation3D.hpp.
EstimateTransformation3D< T >::value_type TRTK::EstimateTransformation3D< T >::getRMS | ( | ) | const [virtual, inherited] |
Returns the root mean square (RMS) error of the estimated transformation.
T | scalar type of the coordinates |
It is assumed, that the computation was done before.
The value type T
must provide a function T sqrt(T value)
which yields the square root of value
.
ErrorObj | If the point sets do not have the same cardinality, an error object is thrown and its error code is set to UNEQUAL_NUMBER_OF_POINTS . |
Implements TRTK::EstimateTransformation< T >.
Definition at line 149 of file EstimateTransformation3D.hpp.
EstimateSimilarityTransformation3D< T >::Matrix3T TRTK::EstimateSimilarityTransformation3D< T >::getRotationMatrix | ( | ) | const |
T | scalar type of the coordinates |
Definition at line 529 of file EstimateSimilarityTransformation3D.hpp.
EstimateSimilarityTransformation3D< T >::value_type TRTK::EstimateSimilarityTransformation3D< T >::getScalingFactor | ( | ) | const |
T | scalar type of the coordinates |
Definition at line 544 of file EstimateSimilarityTransformation3D.hpp.
const EstimateTransformation3D< T >::Matrix4T & TRTK::EstimateTransformation3D< T >::getTransformationMatrix | ( | ) | const [virtual, inherited] |
T | scalar type of the coordinates |
Definition at line 195 of file EstimateTransformation3D.hpp.
EstimateSimilarityTransformation3D< T >::Vector3T TRTK::EstimateSimilarityTransformation3D< T >::getTranslationVector | ( | ) | const |
T | scalar type of the coordinates |
Definition at line 559 of file EstimateSimilarityTransformation3D.hpp.
void TRTK::EstimateTransformation3D< T >::setSourcePoints | ( | const std::vector< Vector3T > & | source_points ) | [inherited] |
Sets the source points.
T | scalar type of the coordinates |
[in] | source_points | 3D coordinates. |
Definition at line 247 of file EstimateTransformation3D.hpp.
void TRTK::EstimateTransformation3D< T >::setSourcePoints | ( | const std::vector< Vector4T, Eigen::aligned_allocator< Vector4T > > & | source_points ) | [inherited] |
Sets the source points.
T | scalar type of the coordinates |
[in] | source_points | 4D homogeneous coordinates. |
Definition at line 265 of file EstimateTransformation3D.hpp.
void TRTK::EstimateTransformation3D< T >::setSourcePoints | ( | const std::vector< Coordinate< T > > & | source_points ) | [inherited] |
Sets the source points.
T | scalar type of the coordinates |
[in] | source_points | The points can either be plain 3D or 4D homogeneous coordinates. |
ErrorObj | If there are any coordinates other than 3D or 4D coordinates, an error object is thrown and its error code is set to WRONG_POINT_SIZE . |
Definition at line 215 of file EstimateTransformation3D.hpp.
void TRTK::EstimateTransformation3D< T >::setTargetPoints | ( | const std::vector< Vector3T > & | target_points ) | [inherited] |
Sets the target points.
T | scalar type of the coordinates |
[in] | target_points | 3D coordinates. |
Definition at line 325 of file EstimateTransformation3D.hpp.
void TRTK::EstimateTransformation3D< T >::setTargetPoints | ( | const std::vector< Vector4T, Eigen::aligned_allocator< Vector4T > > & | target_points ) | [inherited] |
Sets the target points.
T | scalar type of the coordinates |
[in] | target_points | 4D homogeneous coordinates. |
Definition at line 343 of file EstimateTransformation3D.hpp.
void TRTK::EstimateTransformation3D< T >::setTargetPoints | ( | const std::vector< Coordinate< T > > & | target_points ) | [inherited] |
Sets the target points.
T | scalar type of the coordinates |
[in] | target_points | The points can either be plain 3D or 4D homogeneous coordinates. |
ErrorObj | If there are any coordinates other than 3D or 4D coordinates, an error object is thrown and its error code is set to WRONG_POINT_SIZE . |
Definition at line 293 of file EstimateTransformation3D.hpp.
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