#include <vpColorHistogram.h>

Classes
class	Builder

Public Member Functions
	vpColorHistogram ()
	vpColorHistogram (unsigned int N)
void	setBinNumber (unsigned int N)
unsigned int	getBinNumber () const
unsigned int	getNumPixels () const
void	build (const vpImage< vpRGBa > &image, const vpImage< bool > &mask)
void	build (const std::vector< unsigned int > &counts)
void	merge (const vpColorHistogram &other, float alpha)
void	computeProbas (const vpImage< vpRGBa > &image, vpImage< float > &proba) const
void	computeProbas (const vpImage< vpRGBa > &image, vpImage< float > &proba, const vpRect &bb) const
unsigned int	colorToIndex (const vpRGBa &p) const
vpRGBa	indexToColor (unsigned int index) const
double	probability (const vpRGBa &color) const
double	kl (const vpColorHistogram &other) const
double	jsd (const vpColorHistogram &other) const
double	hellinger (const vpColorHistogram &other) const
std::vector< vpRGBa >	mostLikelyColors (unsigned int N) const

Static Public Member Functions
static void	computeSplitHistograms (const vpImage< vpRGBa > &image, const vpImage< bool > &mask, vpColorHistogram &inMask, vpColorHistogram &outsideMask)
static void	computeSplitHistograms (const vpImage< vpRGBa > &image, const vpImage< bool > &mask, const vpRect &bbInside, vpColorHistogram &insideMask, vpColorHistogram &outsideMask)

Detailed Description

Histogram representation of an RGB color distribution In this representation, probabilities are stored in evenly sized bins. It can then be used to compute the probability of a specific color given the approximated color distribution. The number of bins N should be a power of 2.

Definition at line 56 of file vpColorHistogram.h.

Constructor & Destructor Documentation

◆ vpColorHistogram() [1/2]

vpColorHistogram::vpColorHistogram ( )

Definition at line 54 of file vpColorHistogram.cpp.

Referenced by vpColorHistogram::Builder::build(), computeSplitHistograms(), computeSplitHistograms(), hellinger(), jsd(), kl(), and merge().

◆ vpColorHistogram() [2/2]

vpColorHistogram::vpColorHistogram ( unsigned int N )

Definition at line 57 of file vpColorHistogram.cpp.

References setBinNumber().

Member Function Documentation

◆ build() [1/2]

void vpColorHistogram::build ( const std::vector< unsigned int > & counts )

Intermediate method to build an histogram, from a vector containing the occurence counts of each color bins. The vector should have N^3 values, each corresponding to a color bin. To get the color to index correspondence, see colorToIndex.

Parameters

counts the color occurence counts

Definition at line 91 of file vpColorHistogram.cpp.

References vpException::dimensionError.

◆ build() [2/2]

void vpColorHistogram::build	(	const vpImage< vpRGBa > &	image,
		const vpImage< bool > &	mask )

Build the histogram representation and associated color probabilities given an image and a mask. From this image, only the pixels where the mask is true will be used to create the histogram.

Parameters

image	the input image
mask	the mask giving the pixels to use

Definition at line 73 of file vpColorHistogram.cpp.

References vpImage< Type >::bitmap, colorToIndex(), and vpImage< Type >::getSize().

Referenced by computeSplitHistograms(), and computeSplitHistograms().

◆ colorToIndex()

unsigned int vpColorHistogram::colorToIndex ( const vpRGBa & p ) const

inline

Convert an RGB color to an index that can be used to retrieve the probability of this color The alpha channel is ignored.

Parameters

p	the input color

Returns: unsigned int the index used to query the histogram vector

Definition at line 146 of file vpColorHistogram.h.

Referenced by build(), computeProbas(), computeProbas(), computeSplitHistograms(), computeSplitHistograms(), and probability().

◆ computeProbas() [1/2]

void vpColorHistogram::computeProbas	(	const vpImage< vpRGBa > &	image,
		vpImage< float > &	proba ) const

Compute the probabilities of every pixel according to this histogram.

Parameters

image	the input image
proba	Output probability map

Definition at line 124 of file vpColorHistogram.cpp.

References vpImage< Type >::bitmap, colorToIndex(), vpImage< Type >::getHeight(), vpImage< Type >::getSize(), vpImage< Type >::getWidth(), and vpImage< Type >::resize().

◆ computeProbas() [2/2]

void vpColorHistogram::computeProbas	(	const vpImage< vpRGBa > &	image,
		vpImage< float > &	proba,
		const vpRect &	bb ) const

Compute the probabilities of pixels according to this histogram. This version only scores the pixels in the input bounding box.

Parameters

image	the input image
proba	Output probability map
bb	The bounding box where to score the pixels

Definition at line 135 of file vpColorHistogram.cpp.

References colorToIndex(), vpImage< Type >::getHeight(), vpImage< Type >::getWidth(), and vpImage< Type >::resize().

◆ computeSplitHistograms() [1/2]

void vpColorHistogram::computeSplitHistograms	(	const vpImage< vpRGBa > &	image,
		const vpImage< bool > &	mask,
		const vpRect &	bbInside,
		vpColorHistogram &	insideMask,
		vpColorHistogram &	outsideMask )

static

Definition at line 222 of file vpColorHistogram.cpp.

References vpException::badValue, vpImage< Type >::bitmap, build(), colorToIndex(), vpRect::getBottom(), vpRect::getLeft(), vpRect::getRight(), vpImage< Type >::getSize(), vpRect::getTop(), vpImage< Type >::getWidth(), and vpColorHistogram().

◆ computeSplitHistograms() [2/2]

void vpColorHistogram::computeSplitHistograms	(	const vpImage< vpRGBa > &	image,
		const vpImage< bool > &	mask,
		vpColorHistogram &	inMask,
		vpColorHistogram &	outsideMask )

static

Definition at line 191 of file vpColorHistogram.cpp.

References vpException::badValue, vpImage< Type >::bitmap, build(), colorToIndex(), vpImage< Type >::getSize(), and vpColorHistogram().

Referenced by vpColorHistogramMask::updateMask().

◆ getBinNumber()

unsigned int vpColorHistogram::getBinNumber ( ) const

inline

Definition at line 86 of file vpColorHistogram.h.

Referenced by vpColorHistogram::Builder::build().

◆ getNumPixels()

unsigned int vpColorHistogram::getNumPixels ( ) const

inline

Get the number of pixels used to compute this histogram. Can be useful when merging different histograms.

Returns: unsigned int

Definition at line 93 of file vpColorHistogram.h.

◆ hellinger()

double vpColorHistogram::hellinger ( const vpColorHistogram & other ) const

Definition at line 180 of file vpColorHistogram.cpp.

References vpColorHistogram().

◆ indexToColor()

vpRGBa vpColorHistogram::indexToColor ( unsigned int index ) const

inline

Convert an index value to a color.

Parameters

index an index value that should be between 0 and N^3

Returns: vpRGBa a color in the bin corresponding to the index

Definition at line 156 of file vpColorHistogram.h.

References vpRGBa::A, vpRGBa::B, vpRGBa::G, and vpRGBa::R.

Referenced by mostLikelyColors().

◆ jsd()

double vpColorHistogram::jsd ( const vpColorHistogram & other ) const

Definition at line 169 of file vpColorHistogram.cpp.

References kl(), and vpColorHistogram().

◆ kl()

double vpColorHistogram::kl ( const vpColorHistogram & other ) const

Definition at line 155 of file vpColorHistogram.cpp.

References vpException::badValue, and vpColorHistogram().

Referenced by jsd().

◆ merge()

void vpColorHistogram::merge	(	const vpColorHistogram &	other,
		float	alpha )

Merge this histogram with an another. This histogram is modified. The probabilities are interpolated between this histogram's values and the other's.

Parameters

other	The histogram to merge with
alpha	the interpolation/importance factor of the other histogram. between 0 and 1. 1 completely replaces this histogram with other.

Definition at line 106 of file vpColorHistogram.cpp.

References vpException::badValue, and vpColorHistogram().

◆ mostLikelyColors()

std::vector< vpRGBa > vpColorHistogram::mostLikelyColors ( unsigned int N ) const

inline

Get the N most likely colors according to this histogram.

Parameters

N	the number of colors to retrieve

Returns: std::vector<vpRGBa> the most likely colors

Definition at line 191 of file vpColorHistogram.h.

References indexToColor().

◆ probability()

double vpColorHistogram::probability ( const vpRGBa & color ) const

inline

Get the probability of an RGB color according to this histogram.

Parameters

color the color

Returns: double the estimated probability (0-1)

Definition at line 172 of file vpColorHistogram.h.

References colorToIndex().

Referenced by vpProbaComputer::vpProbaComputer().

◆ setBinNumber()

void vpColorHistogram::setBinNumber ( unsigned int N )

Change the number of bins per color component that the histogram has After calling this method, the histogram will be reset and the values will not be kept.

Parameters

N	the number of bins per RGB component: the histogram will have N^3 bins in total. N should be a power of 2 between 1 and 128

Definition at line 62 of file vpColorHistogram.cpp.

References vpException::badValue.

Referenced by vpColorHistogram().

Classes

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ vpColorHistogram() [1/2]

◆ vpColorHistogram() [2/2]

Member Function Documentation

◆ build() [1/2]

◆ build() [2/2]

◆ colorToIndex()

◆ computeProbas() [1/2]

◆ computeProbas() [2/2]

◆ computeSplitHistograms() [1/2]

◆ computeSplitHistograms() [2/2]

◆ getBinNumber()

◆ getNumPixels()

◆ hellinger()

◆ indexToColor()

◆ jsd()

◆ kl()

◆ merge()

◆ mostLikelyColors()

◆ probability()

◆ setBinNumber()