Libs/Alignment/Procrustes3D.h

Classes

	Name
struct	SimilarityTransform3D
class	Procrustes3D

Source code

```cpp

pragma once

include

struct SimilarityTransform3D { vnl_matrix_fixed rotation; double scale; vnl_vector_fixed translation; };

class Procrustes3D { public: typedef double RealType; typedef vnl_vector_fixed PointType; typedef std::vector ShapeType; typedef ShapeType::iterator ShapeIteratorType;

typedef std::vector ShapeListType; typedef ShapeListType::iterator ShapeListIteratorType;

typedef std::vector SimilarityTransformListType; typedef SimilarityTransformListType::iterator SimilarityTransformListIteratorType;

typedef vnl_matrix_fixed TransformMatrixType; typedef std::vector TransformMatrixListType; typedef TransformMatrixListType::iterator TransformMatrixIteratorType;

public: Procrustes3D() : m_Scaling(true), m_RotationTranslation(true) {} Procrustes3D(bool do_scaling, bool do_rotation_translation) : m_Scaling(do_scaling), m_RotationTranslation(do_rotation_translation) {}

bool GetScaling() const { return m_Scaling; } void ScalingOn() { m_Scaling = true; } void ScalingOff() { m_Scaling = false; }

bool GetRotationTranslation() const { return m_RotationTranslation; } void RotationTranslationOn() { m_RotationTranslation = true; } void RotationTranslationOff() { m_RotationTranslation = false; }

// Align a list of shapes using Generalized Procrustes Analysis void AlignShapes(SimilarityTransformListType& transforms, ShapeListType& shapes);

void RemoveTranslation(SimilarityTransformListType& transforms, ShapeListType& shapes);

// Helper function to transform a shape by a similarity transform static void TransformShape(ShapeType& shape, SimilarityTransform3D& transform);

// Helper function to transform a list of shapes by a list of transforms static void TransformShapes(ShapeListType& shapes, SimilarityTransformListType& transforms);

static RealType ComputeSumOfSquares(ShapeListType& shapes);

// Transform from Configuration space to Procrustes space. Translation // followed by rotation and scaling. void ConstructTransformMatrices(SimilarityTransformListType& transforms, TransformMatrixListType& transformMatrices); void ConstructTransformMatrix(SimilarityTransform3D& transform, TransformMatrixType& transformMatrix);

void ComputeMeanShape(ShapeType& mean, ShapeListType& shapeList); void ComputeCenterOfMass(ShapeType& shape, PointType& center); void CenterShape(ShapeType& shape);

// this is the center which needed for translation of the shapes to coincide on the image origin // so that the whole object is in the image and won't go outside void ComputeCommonCenter(SimilarityTransformListType& transforms, PointType& center);

// Align source shape to target using Ordinary Procrustes Analysis (translation, scaling and rotation) // the target shape is assumed to be centered at the origin void AlignSourceToTarget(SimilarityTransform3D& transform, ShapeType& target, ShapeType& source);

/ The median shape is defined as the shape with the minimum sum of Euclidean L1 norms to all other shapes in that group. / int ComputeMedianShape(ShapeListType& shapeList);

private: // Align two shapes (rotation & scale) using Ordinary Procrustes Analysis void AlignTwoShapes(SimilarityTransform3D& transform, ShapeType& shape1, ShapeType& shape2);

bool m_Scaling; // a flag to factor out scaling bool m_RotationTranslation; // a flag for rotation + translation + (scale depending on m_Scaling), if false, the // transformation will only be scaling }; ```

Updated on 2026-03-31 at 16:02:10 +0000