DGtal::MeaningfulScaleAnalysis< TProfile > Class Template Reference

Aim: This class implements different methods used to define the meaningful scale analysis as proposed in [63] . In particular, it uses the Profile class to represent a multi-scale profile and to compute a meaningful scale. It also permits to get a noise estimation from the given profile. More...

#include <DGtal/math/MeaningfulScaleAnalysis.h>

Public Types
typedef TProfile	Profile

Public Member Functions
	MeaningfulScaleAnalysis (ConstAlias< Profile > aProfile)
	~MeaningfulScaleAnalysis ()
void	computeMeaningfulScales (std::vector< std::pair< unsigned int, unsigned int > > &intervals, const unsigned int minSize=1, const double maxSlope=-0.2, const double minSlope=-1e10) const
std::pair< bool, double >	getSlopeFromMeaningfulScales (const double maxSlope=-0.2, const double minSlope=-1e10, const unsigned int minSize=2) const
unsigned int	noiseLevel (const unsigned int minSize=1, const double maxSlope=-0.2, const double minSlope=-1e10) const
unsigned int	lowerBoundedNoiseLevel (const unsigned int minSize=1, const double maxSlope=-0.2, const double minSlope=-1e10, const double lowerBoundAtScale1=1.0, const double lowerBoundSlope=-2.0) const
void	selfDisplay (std::ostream &out) const
bool	isValid () const

Protected Member Functions
	MeaningfulScaleAnalysis ()

Protected Attributes
const Profile &	myProfile

Private Member Functions
	MeaningfulScaleAnalysis (const MeaningfulScaleAnalysis &other)
MeaningfulScaleAnalysis &	operator= (const MeaningfulScaleAnalysis &other)

Detailed Description

template<typename TProfile>
class DGtal::MeaningfulScaleAnalysis< TProfile >

Aim: This class implements different methods used to define the meaningful scale analysis as proposed in [63] . In particular, it uses the Profile class to represent a multi-scale profile and to compute a meaningful scale. It also permits to get a noise estimation from the given profile.

Description of class 'MeaningfulScaleAnalysis'

A typical example is for instance the length of maximal segments obtained at different scales.

First we construct a Profile:

// we need to have the Profile header:
#include "DGtal/math/Profile.h"
 
// with a log functor to obtain log scale profile:
struct LogFct{
  float operator()(const float &a) const {
   return log(a);
   }
};
 
...
 
Profile<LogFct> sp (Profile<LogFct>::MEAN);
sp.init(6);

Then, we can add values to the profile:

sp.addValue(0,22);
sp.addValue(1,15);
sp.addValue(2,8);
sp.addValue(3,17);
sp.addValue(4,7);
sp.addValue(5,2);      

Finally we can construct the MeaningfulScaleAnalysis object and obtain the meaningful scale:

MeaningfulScaleAnalysis<Profile<LogFct>> msa(sp);
std::vector< std::pair<uint, uint> > intervals;      
msa.computeMeaningfulScales(intervals, 1);
unsigned int n = msa.noiseLevel();

See also

testMeaningfulScaleAnalysis

Template Parameters

TProfile

the type of the profile class.

Definition at line 112 of file MeaningfulScaleAnalysis.h.

Member Typedef Documentation

Profile

template<typename TProfile >

typedef TProfile DGtal::MeaningfulScaleAnalysis< TProfile >::Profile

Definition at line 117 of file MeaningfulScaleAnalysis.h.

Constructor & Destructor Documentation

MeaningfulScaleAnalysis() [1/3]

template<typename TProfile >

DGtal::MeaningfulScaleAnalysis< TProfile >::MeaningfulScaleAnalysis

(

ConstAlias< Profile >

aProfile

)

Constructor

~MeaningfulScaleAnalysis()

template<typename TProfile >

DGtal::MeaningfulScaleAnalysis< TProfile >::~MeaningfulScaleAnalysis

(

)

Destructor.

MeaningfulScaleAnalysis() [2/3]

template<typename TProfile >

DGtal::MeaningfulScaleAnalysis< TProfile >::MeaningfulScaleAnalysis ( )

protected

Constructor. Forbidden by default (protected to avoid g++ warnings).

MeaningfulScaleAnalysis() [3/3]

template<typename TProfile >

DGtal::MeaningfulScaleAnalysis< TProfile >::MeaningfulScaleAnalysis ( const MeaningfulScaleAnalysis< TProfile > &  other )

private

Copy constructor.

Parameters

other

the object to clone. Forbidden by default.

Member Function Documentation

computeMeaningfulScales()

template<typename TProfile >

void DGtal::MeaningfulScaleAnalysis< TProfile >::computeMeaningfulScales	(	std::vector< std::pair< unsigned int, unsigned int > > &	intervals,
		const unsigned int	minSize = 1,
		const double	maxSlope = -0.2,
		const double	minSlope = -1e10
	)		const

A meaningful scale is an interval of scales of length no smaller than [min_width] and in which the profile has slopes below [max_slope] and above [min_slope]. This method computes the sequence of meaningful scales for surfel [idx].

Parameters

[out]	intervals	(returns) a list of meaningful scales.
[in]	minSize	the minimum length for the meaningful scales.
[in]	maxSlope	the maximum allowed slope for length evolution.
[in]	minSlope	the minimum allowed slope for length evolution.

Referenced by TEST_CASE().

getSlopeFromMeaningfulScales()

template<typename TProfile >

std::pair< bool, double > DGtal::MeaningfulScaleAnalysis< TProfile >::getSlopeFromMeaningfulScales	(	const double	maxSlope = -0.2,
		const double	minSlope = -1e10,
		const unsigned int	minSize = 2
	)		const

Compute the profile slope of the first meaningful scale interval computed by a simple linear regression model.

Returns

a pair<bool, double> giving the slope and indicating if a meaningful scale was found or not. If no meaningful scale interval was found, it simply return the slope obtained from the linear regression.

Parameters

[in]	maxSlope	the maximum allowed slope for length evolution.
[in]	minSlope	the minimum allowed slope for length evolution.
[in]	minSize	the minimum length for the meaningful scales.

Referenced by TEST_CASE().

isValid()

template<typename TProfile >

bool DGtal::MeaningfulScaleAnalysis< TProfile >::isValid

(

)

const

Checks the validity/consistency of the object.

Returns

'true' if the object is valid, 'false' otherwise.

lowerBoundedNoiseLevel()

template<typename TProfile >

unsigned int DGtal::MeaningfulScaleAnalysis< TProfile >::lowerBoundedNoiseLevel	(	const unsigned int	minSize = 1,
		const double	maxSlope = -0.2,
		const double	minSlope = -1e10,
		const double	lowerBoundAtScale1 = 1.0,
		const double	lowerBoundSlope = -2.0
	)		const

The noise level is the first scale of the first meaningful scale. A meaningful scale is an interval of scales of length no smaller than [minWidth] and in which the profile has slopes below [maxSlope]. The lower bounded noise level also requires minimum lenghs for different scales. Therefore the profile must be greater that [lower_bound_at_scale_1]+[lower_bound_slope]*scale.

Parameters

[in]	minSize	the minimum length for the meaningful scales.
[in]	maxSlope	the maximum allowed slope for length evolution.
[in]	minSlope	the minimum allowed slope for length evolution.
[in]	lowerBoundAtScale1	the lower bound for the profile at scale 1.
[in]	lowerBoundSlope	the slope of the lower bound for the profile (for instance -1 for digital contours, -3 for digital image graphs since area values are divided by (scale)^3.

Returns

the noise level or zero is none was found.

See also

meaningfulScales

Referenced by TEST_CASE().

noiseLevel()

template<typename TProfile >

unsigned int DGtal::MeaningfulScaleAnalysis< TProfile >::noiseLevel	(	const unsigned int	minSize = 1,
		const double	maxSlope = -0.2,
		const double	minSlope = -1e10
	)		const

The noise level is the first scale of the first meaningful scale. A meaningful scale is an interval of scales of length no smaller than [min_width] and in which the profile has slopes below [max_slope].

Parameters

[in]	minSize	the minimum length for the meaningful scales.
[in]	maxSlope	the maximum allowed slope for length evolution.
[in]	minSlope	the minimum allowed slope for length evolution.

Returns

the noise level or zero is none was found.

See also

meaningfulScales

Referenced by TEST_CASE().

operator=()

template<typename TProfile >

MeaningfulScaleAnalysis & DGtal::MeaningfulScaleAnalysis< TProfile >::operator= ( const MeaningfulScaleAnalysis< TProfile > &  other )

private

Assignment.

Parameters

other

the object to copy.

Returns

a reference on 'this'. Forbidden by default.

selfDisplay()

template<typename TProfile >

void DGtal::MeaningfulScaleAnalysis< TProfile >::selfDisplay

(

std::ostream &

out

)

const

Writes/Displays the object on an output stream.

Parameters

out	the output stream where the object is written.

Field Documentation

myProfile

template<typename TProfile >

const Profile& DGtal::MeaningfulScaleAnalysis< TProfile >::myProfile

protected

Definition at line 234 of file MeaningfulScaleAnalysis.h.

---

The documentation for this class was generated from the following file:

• MeaningfulScaleAnalysis.h