DGtal 1.4.0
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Aim: Implements Digital Surface Regularization as described in [31]. More...
#include <DGtal/geometry/surfaces/DigitalSurfaceRegularization.h>
Public Types | |
typedef TDigitalSurface | DigSurface |
DigitalSurface type. | |
typedef TDigitalSurface::DigitalSurfaceContainer | DigitalSurfaceContainer |
Digital Surface Container type. | |
typedef Shortcuts< Z3i::KSpace > | SH3 |
We rely on the Shortcuts 3D types. | |
typedef ShortcutsGeometry< Z3i::KSpace > | SHG3 |
We rely on the ShortcutsGeometry 3D types. | |
typedef std::vector< Z3i::RealPoint > | Positions |
Pointels position container. | |
typedef std::vector< Z3i::RealVector > | Normals |
Pointels position container. | |
Public Member Functions | |
BOOST_CONCEPT_ASSERT ((concepts::CDigitalSurfaceContainer< DigitalSurfaceContainer >)) | |
DigitalSurfaceRegularization (CountedPtr< DigSurface > aDigSurf) | |
~DigitalSurfaceRegularization ()=default | |
DigitalSurfaceRegularization (const DigitalSurfaceRegularization &other)=delete | |
DigitalSurfaceRegularization (DigitalSurfaceRegularization &&other)=delete | |
DigitalSurfaceRegularization & | operator= (const DigitalSurfaceRegularization &other)=delete |
DigitalSurfaceRegularization & | operator= (DigitalSurfaceRegularization &&other)=delete |
void | attachNormalVectors (const std::function< SHG3::RealVector(SH3::SCell &)> &normalFunc) |
void | attachConvolvedTrivialNormalVectors (const Parameters someParams=SH3::defaultParameters()|SHG3::defaultParameters()) |
void | init (const double alpha=0.001, const double beta=1.0, const double gamma=0.05) |
Initialize the parameters of the energy function. | |
void | init (ConstAlias< std::vector< double > > alphas, ConstAlias< std::vector< double > > betas, ConstAlias< std::vector< double > > gammas) |
Initialize the parameters of the energy function. | |
double | computeGradient () |
double | computeGradientLocalWeights () |
template<typename AdvectionFunction > | |
double | regularize (const unsigned int nbIters, const double dt, const double epsilon, const AdvectionFunction &advectionFunc) |
Main regularization loop. | |
double | regularize (const unsigned int nbIters=200, const double dt=1.0, const double epsilon=0.0001) |
Main regularization loop. | |
SHG3::RealPoint | getRegularizedPosition (const SH3::Cell &aPointel) |
const Positions & | getRegularizedPositions () const |
const Positions & | getOriginalPositions () const |
const SH3::Cell2Index & | getCellIndex () const |
const Normals & | getNormalVectors () const |
const SH3::Surfel2Index & | getSurfelIndex () const |
void | reset () |
void | selfDisplay (std::ostream &out) const |
bool | isValid () const |
void | enableVerbose () |
void | disasbleVerbose () |
Static Public Member Functions | |
static void | clampedAdvection (SHG3::RealPoint &p, const SHG3::RealPoint &orig, const SHG3::RealVector &v) |
Private Member Functions | |
void | cacheInit () |
Private Attributes | |
double | myAlpha |
Data attachment term coefficient. | |
double | myBeta |
Alignment term coefficient. | |
double | myGamma |
Fairness term coefficient. | |
const std::vector< double > * | myAlphas |
Data attachment term local coefficients. | |
const std::vector< double > * | myBetas |
Alignment attachment term local coefficients. | |
const std::vector< double > * | myGammas |
Fairness attachment term local coefficients. | |
bool | myConstantCoeffs |
Flag if the gradient has constant weights for the init method and gradient. | |
bool | myInit |
Flag if the object has been set up properly. | |
bool | myVerbose |
Flag for verbose messages. | |
CountedPtr< DigSurface > | myDigitalSurface |
Input DigitalSurface to regularize. | |
Positions | myOriginalPositions |
Copy of the input pointels positions. | |
Positions | myRegularizedPositions |
Regularized vertices. | |
Normals | myNormals |
Normals. | |
Positions | myGradient |
Gradient of the energy w.r.t. vertex positons. | |
Positions | myGradientAlign |
Internal members to store precomputed topological informations. | |
SH3::KSpace | myK |
Instance of the KSpace. | |
SH3::SurfelRange | mySurfels |
Indexed surface elements. | |
SH3::Surfel2Index | mySurfelIndex |
Surfel Index. | |
SH3::Cell2Index | myPointelIndex |
Indices for pointels. | |
std::vector< SH3::Idx > | myAlignPointelsIdx |
Indices of adjacent pointels for the Alignement energy term. | |
std::vector< SH3::Cell > | myAlignPointels |
Adjacent pointels for the Alignement energy term. | |
std::vector< unsigned char > | myNumberAdjEdgesToPointel |
Number of adjacent edges to pointels. | |
std::vector< SH3::Idx > | myFairnessPointelsIdx |
Indices of cells foor the Fairness term. | |
std::vector< unsigned char > | myNbAdjacent |
Number of adjacent faces to given vertex. | |
SH3::PolygonalSurface::FaceRange | myFaces |
All faces of the dual digital surfacce. | |
Aim: Implements Digital Surface Regularization as described in [31].
Description of template class 'DigitalSurfaceRegularization'
Given a digital surface and a normal vector field attached to the surfels, this class performs a regularization of the digital surface vertices to obtain a piecewise smooth surface such that each quad of the output surface is as perpendicular as possible to the given input normal vector field.
If \(P\) denotes the vertices of the input digital surface, \(F\) the set of (quadrilateral) faces and \(n_f\) an estimated normal vector on the face \(f\), we want the quad surface vertex positions \(P^*\) that minimizes the following energy function:
\[\mathcal{E}(P) := \alpha \sum_{i=1}^{n} \|p_i - \hat{p}_i\|^2 + \beta \sum_{f\in F} \sum_{{e_j} \in \partial{f} } ( e_j \cdot n_{f} )^2 + \gamma \sum_{i=1}^{n} \|\hat{p}_i - \hat{b}_i\|^2\,.\]
where \("\cdot"\) is the standard \(\mathbb{R}^3\) scalar product, \(e_j\in \partial{f}\) is an edge of the face \(f\) (and is equal to some \(p_k - p_l\)) and \( \hat{b}_i\) is the barycenter of the vertices adjacent to \(\hat{p}_i\).
To minimize this energy, instead of solving the associated sparse linear system as described in [31], we perform a gradient descent strategy which allows us a finer control over the vertices displacement (see advection methods).
TDigitalSurface | a Digital Surface type (see DigitalSurface). |
Definition at line 88 of file DigitalSurfaceRegularization.h.
typedef TDigitalSurface::DigitalSurfaceContainer DGtal::DigitalSurfaceRegularization< TDigitalSurface >::DigitalSurfaceContainer |
Digital Surface Container type.
Definition at line 96 of file DigitalSurfaceRegularization.h.
typedef TDigitalSurface DGtal::DigitalSurfaceRegularization< TDigitalSurface >::DigSurface |
DigitalSurface type.
Definition at line 94 of file DigitalSurfaceRegularization.h.
typedef std::vector<Z3i::RealVector> DGtal::DigitalSurfaceRegularization< TDigitalSurface >::Normals |
Pointels position container.
Definition at line 109 of file DigitalSurfaceRegularization.h.
typedef std::vector<Z3i::RealPoint> DGtal::DigitalSurfaceRegularization< TDigitalSurface >::Positions |
Pointels position container.
Definition at line 106 of file DigitalSurfaceRegularization.h.
typedef Shortcuts<Z3i::KSpace> DGtal::DigitalSurfaceRegularization< TDigitalSurface >::SH3 |
We rely on the Shortcuts 3D types.
Definition at line 100 of file DigitalSurfaceRegularization.h.
typedef ShortcutsGeometry<Z3i::KSpace> DGtal::DigitalSurfaceRegularization< TDigitalSurface >::SHG3 |
We rely on the ShortcutsGeometry 3D types.
Definition at line 103 of file DigitalSurfaceRegularization.h.
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Default constructor.
Definition at line 114 of file DigitalSurfaceRegularization.h.
References DGtal::Shortcuts< TKSpace >::getKSpace(), DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myDigitalSurface, and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myK.
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Destructor.
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Copy constructor.
other | the object to clone. |
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Move constructor.
other | the object to move. |
void DGtal::DigitalSurfaceRegularization< TDigitalSurface >::attachConvolvedTrivialNormalVectors | ( | const Parameters | someParams = SH3::defaultParameters()|SHG3::defaultParameters() | ) |
Attach convolved trivial normal vectors to the digital surface (cf ShortCutsGeometry::getCTrivialNormalVectors).
An important parameter is the radius used to estimate the normal vectors (t-ring, default=3.0).
someParams | the parameters (t-ring, default=3.0 used in the local convolution). |
Referenced by main(), and TEST_CASE().
void DGtal::DigitalSurfaceRegularization< TDigitalSurface >::attachNormalVectors | ( | const std::function< SHG3::RealVector(SH3::SCell &)> & | normalFunc | ) |
Attach normal vectors from a generic function that associates a normal vector to each surfel.
normalFunc | a function (or a lambda, or a functor) that maps surfels (SH3::SCell) to normal vectors (SH3::RealVector). |
Referenced by TEST_CASE().
DGtal::DigitalSurfaceRegularization< TDigitalSurface >::BOOST_CONCEPT_ASSERT | ( | (concepts::CDigitalSurfaceContainer< DigitalSurfaceContainer >) | ) |
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Internal init method to set up topological caches.
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Static method to be used in regularize() that clamps to regularized point p when shifted by v in the unit cube centered at orig.
[in,out] | p | the point to advect. |
[in] | orig | the associated point in the original surface. |
[in] | v | the advection vector. |
Definition at line 292 of file DigitalSurfaceRegularization.h.
double DGtal::DigitalSurfaceRegularization< TDigitalSurface >::computeGradient | ( | ) |
Compute the energy gradient vector and return the energy value.
Referenced by TEST_CASE().
double DGtal::DigitalSurfaceRegularization< TDigitalSurface >::computeGradientLocalWeights | ( | ) |
Compute the energy gradient vector and return the energy value.
This method assumes that you have local alpha, beta and gamma weights.
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Disable verbose messages.
Definition at line 404 of file DigitalSurfaceRegularization.h.
References DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myVerbose.
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Enable verbose messages.
Definition at line 399 of file DigitalSurfaceRegularization.h.
References DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myVerbose.
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Definition at line 343 of file DigitalSurfaceRegularization.h.
References DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myInit, and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myPointelIndex.
Referenced by TEST_CASE().
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Definition at line 353 of file DigitalSurfaceRegularization.h.
References DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myInit, and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myNormals.
Referenced by TEST_CASE().
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Definition at line 333 of file DigitalSurfaceRegularization.h.
References DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myInit, and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myOriginalPositions.
Referenced by TEST_CASE().
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[in] | aPointel | the digital surface pointel. |
Definition at line 311 of file DigitalSurfaceRegularization.h.
References DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myInit, DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myK, DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myPointelIndex, and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myRegularizedPositions.
Referenced by TEST_CASE().
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Definition at line 323 of file DigitalSurfaceRegularization.h.
References DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myInit, and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myRegularizedPositions.
Referenced by main(), and TEST_CASE().
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Definition at line 364 of file DigitalSurfaceRegularization.h.
References DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myInit, and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::mySurfelIndex.
Referenced by TEST_CASE().
void DGtal::DigitalSurfaceRegularization< TDigitalSurface >::init | ( | const double | alpha = 0.001, |
const double | beta = 1.0, | ||
const double | gamma = 0.05 ) |
Initialize the parameters of the energy function.
This init() method attaches the same weights to all vertices.
[in] | alpha | the data attachment term coeff. (default=0.001) |
[in] | beta | the alignemnt term coeff. (default=1.0) |
[in] | gamma | the fairness term coeef. (default=0.05) |
Referenced by main(), and TEST_CASE().
void DGtal::DigitalSurfaceRegularization< TDigitalSurface >::init | ( | ConstAlias< std::vector< double > > | alphas, |
ConstAlias< std::vector< double > > | betas, | ||
ConstAlias< std::vector< double > > | gammas ) |
Initialize the parameters of the energy function.
This init() method considers local weights per vertex (all verctors must have the same size: the number of pointels of the original surface).
[in] | alphas | the data attachment term coeff. |
[in] | betas | the alignemnt term coeff. |
[in] | gammas | the fairness term coeef. |
bool DGtal::DigitalSurfaceRegularization< TDigitalSurface >::isValid | ( | ) | const |
Checks the validity/consistency of the object.
Referenced by TEST_CASE().
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Copy assignment operator.
other | the object to copy. |
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Move assignment operator.
other | the object to move. |
double DGtal::DigitalSurfaceRegularization< TDigitalSurface >::regularize | ( | const unsigned int | nbIters, |
const double | dt, | ||
const double | epsilon, | ||
const AdvectionFunction & | advectionFunc ) |
Main regularization loop.
This method performs the main minimization loop of the energy using a gradient descent scheme (with automatic update of the learning step). The iterative process stops either when the number of steps reaches nbIters, or when the \(l_\infty\) norm of the energy gradient is below epsilon.
The last parameter is a function that describes how regularized points are advected during the gradient descent. By default, points are shifted by a fraction of the energy gradient vector (and the default function is thus \( p \leftarrow p + v\) with \( v = -dt \nabla E_p\)). See
The energy at the final step is returned.
[in] | nbIters | maxium number of steps |
[in] | dt | initial learning rate |
[in] | epsilon | minimum l_infity norm of the gradient vector |
[in] | advectionFunc | advection function/functor/lambda to move a regularized point &a p associated with the original point o w.r.t to a displacement vector v (default = p+v) |
AdvectionFunction | type of advection function, functor or lambda (RealPoint, RealPoint, RealVector)->RealPoint. |
Referenced by main(), DGtal::DigitalSurfaceRegularization< TDigitalSurface >::regularize(), and TEST_CASE().
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Main regularization loop.
This method performs the main minimization loop of the energy using a gradient descent scheme (with automatic update of the learning step). The iterative process stops either when the number of steps reaches nbIters, or when the \(l_\infty\) norm of the energy gradient is below epsilon.
This methods uses the default advection function \( p = p + v\).
The energy at the final step is returned.
[in] | nbIters | maxium number of steps (default=200) |
[in] | dt | initial learning rate (default = 1.0) |
[in] | epsilon | minimum l_infity norm of the gradient vector (default = 0.0001) |
Definition at line 273 of file DigitalSurfaceRegularization.h.
References dt, and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::regularize().
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Reset the regularized vertices positions to the original one.
Definition at line 374 of file DigitalSurfaceRegularization.h.
References DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myInit, DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myOriginalPositions, and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::myRegularizedPositions.
Referenced by TEST_CASE().
void DGtal::DigitalSurfaceRegularization< TDigitalSurface >::selfDisplay | ( | std::ostream & | out | ) | const |
Writes/Displays the object on an output stream.
out | the output stream where the object is written. |
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Adjacent pointels for the Alignement energy term.
Definition at line 479 of file DigitalSurfaceRegularization.h.
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Indices of adjacent pointels for the Alignement energy term.
Definition at line 477 of file DigitalSurfaceRegularization.h.
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Data attachment term coefficient.
Definition at line 419 of file DigitalSurfaceRegularization.h.
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Data attachment term local coefficients.
Definition at line 426 of file DigitalSurfaceRegularization.h.
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Alignment term coefficient.
Definition at line 421 of file DigitalSurfaceRegularization.h.
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Alignment attachment term local coefficients.
Definition at line 428 of file DigitalSurfaceRegularization.h.
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Flag if the gradient has constant weights for the init method and gradient.
Definition at line 433 of file DigitalSurfaceRegularization.h.
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Input DigitalSurface to regularize.
Definition at line 442 of file DigitalSurfaceRegularization.h.
Referenced by DGtal::DigitalSurfaceRegularization< TDigitalSurface >::DigitalSurfaceRegularization().
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All faces of the dual digital surfacce.
Definition at line 487 of file DigitalSurfaceRegularization.h.
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Indices of cells foor the Fairness term.
Definition at line 483 of file DigitalSurfaceRegularization.h.
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Fairness term coefficient.
Definition at line 423 of file DigitalSurfaceRegularization.h.
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Fairness attachment term local coefficients.
Definition at line 430 of file DigitalSurfaceRegularization.h.
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Gradient of the energy w.r.t. vertex positons.
Definition at line 454 of file DigitalSurfaceRegularization.h.
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Internal members to store precomputed topological informations.
Gradient of the quad alignement w.r.t. vertex positons
Definition at line 462 of file DigitalSurfaceRegularization.h.
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Flag if the object has been set up properly.
Definition at line 436 of file DigitalSurfaceRegularization.h.
Referenced by DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getCellIndex(), DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getNormalVectors(), DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getOriginalPositions(), DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getRegularizedPosition(), DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getRegularizedPositions(), DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getSurfelIndex(), and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::reset().
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Instance of the KSpace.
Definition at line 465 of file DigitalSurfaceRegularization.h.
Referenced by DGtal::DigitalSurfaceRegularization< TDigitalSurface >::DigitalSurfaceRegularization(), and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getRegularizedPosition().
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Number of adjacent faces to given vertex.
Definition at line 485 of file DigitalSurfaceRegularization.h.
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Normals.
Definition at line 451 of file DigitalSurfaceRegularization.h.
Referenced by DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getNormalVectors().
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Number of adjacent edges to pointels.
Definition at line 481 of file DigitalSurfaceRegularization.h.
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Copy of the input pointels positions.
Definition at line 445 of file DigitalSurfaceRegularization.h.
Referenced by DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getOriginalPositions(), and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::reset().
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Indices for pointels.
Definition at line 474 of file DigitalSurfaceRegularization.h.
Referenced by DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getCellIndex(), and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getRegularizedPosition().
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Regularized vertices.
Definition at line 448 of file DigitalSurfaceRegularization.h.
Referenced by DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getRegularizedPosition(), DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getRegularizedPositions(), and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::reset().
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Surfel Index.
Definition at line 471 of file DigitalSurfaceRegularization.h.
Referenced by DGtal::DigitalSurfaceRegularization< TDigitalSurface >::getSurfelIndex().
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Indexed surface elements.
Definition at line 468 of file DigitalSurfaceRegularization.h.
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Flag for verbose messages.
Definition at line 439 of file DigitalSurfaceRegularization.h.
Referenced by DGtal::DigitalSurfaceRegularization< TDigitalSurface >::disasbleVerbose(), and DGtal::DigitalSurfaceRegularization< TDigitalSurface >::enableVerbose().