class with tools for image intensity remapping using histograms, like histogram matching and histogram equalization More...

#include <HistogramTools.h>

Public Member Functions
	HistogramTools ()
	constructor

	~HistogramTools ()
	destructor

Static Public Member Functions
static void	RemapHistogramInROI (ArrayGrid< double > pInGrid, common::RectangularROI< int > rroi, histogram::IntHistogram fhCumulativeInput, histogram::FloatHistogram *fhCumulativeReference)
	remap intensities in an image ROI to follow a target histogram References http://en.wikipedia.org/wiki/Histogram_equalization -> Backprojection http://en.wikipedia.org/wiki/Histogram_matching More...

static double	MatchHistogramValue (double inValue, histogram::IntHistogram fhIncomingCumulativeHistogram, histogram::FloatHistogram fhCumulativeReferenceHistogram)
	matches an intensity from an image with ihIncomingCumulativeHistogram to transform it to ihCumulativeReferenceHistogram More...

static Image *	RobustLinearRescale (Image *pSourceImage, double lowerFraction=0.01, double upperFraction=0.99)
	Performs robust linear intensity rescaling, creating a new object as result A new image is created, which becomes the responsability of the caller. More...

static bool	RobustLinearRescaleNoNew (Image *pSourceImage, double lowerFraction=0.01, double upperFraction=0.99)
	Performs robust linear intensity rescaling on the image itself, creating no new object (No new image is created; old values are overwritten) More...

static void	HistogramEqualizeSingleBand (ArrayGrid< double > *pInOutGrid)
	performs histogram equalization on a single band More...

static Image *	HistogramEqualizePerBand (Image *pInImage)
	performs histogram equalization on an image, but for all bands independantly More...

static Image *	HistogramEqualizeHSI (Image *pInImage)
	performs histogram equalization on an RGB image using transformation to HSI color space RGB colors are transformed to HSI, and only the I component is equalized; after that, the result is transformed back to RGB More...

static Image *	ColorHistogramEqualize (Image *pInImage)
	performs histogram equalization on an RGB image using transformation to CIE-Lab color space RGB colors are transformed to CIE-Lab, and only the L component is equalized; after that, the result is transformed back to RGB (values are clipped to range 0-255) More...

Detailed Description

class with tools for image intensity remapping using histograms, like histogram matching and histogram equalization

Member Function Documentation

Image * stira::contrastenhance::HistogramTools::ColorHistogramEqualize ( Image * pInImage )

static

performs histogram equalization on an RGB image using transformation to CIE-Lab color space RGB colors are transformed to CIE-Lab, and only the L component is equalized; after that, the result is transformed back to RGB (values are clipped to range 0-255)

Parameters

pInImage the input image

References stira::imagedata::Image::Clone(), stira::imagedata::Image::GetBands(), stira::imagedata::Image::GetImageName(), stira::imagedata::Image::GetNumberOfBands(), stira::imagedata::Image::LabTosRGB(), stira::imagedata::Image::SetImageName(), and stira::imagedata::Image::sRGBToLab().

Image * stira::contrastenhance::HistogramTools::HistogramEqualizeHSI ( Image * pInImage )

static

performs histogram equalization on an RGB image using transformation to HSI color space RGB colors are transformed to HSI, and only the I component is equalized; after that, the result is transformed back to RGB

Parameters

pInImage the input image

References stira::imagedata::Image::Clone(), stira::imagedata::Image::GetBands(), stira::imagedata::Image::GetImageName(), stira::imagedata::Image::GetNumberOfBands(), stira::imagedata::Image::HSIToRGB(), stira::imagedata::Image::RGBToHSI(), and stira::imagedata::Image::SetImageName().

Image * stira::contrastenhance::HistogramTools::HistogramEqualizePerBand ( Image * pInImage )

static

performs histogram equalization on an image, but for all bands independantly

Parameters

pInImage the input image

References stira::imagedata::Image::Clone(), stira::imagedata::Image::GetBands(), stira::imagedata::Image::GetImageName(), stira::imagedata::Image::GetNumberOfBands(), and stira::imagedata::Image::SetImageName().

void stira::contrastenhance::HistogramTools::HistogramEqualizeSingleBand ( ArrayGrid< double > * pInOutGrid )

static

performs histogram equalization on a single band

Parameters

pInOutGrid the input grid; values are changed on source data

References stira::histogram::IntHistogram::ConvertInCumulativeHistogram(), stira::histogram::HistogramMaster< T >::GetBinValue(), stira::imagedata::ArrayGrid< T >::GetHeight(), stira::imagedata::GridStatistics< T >::GetMinMax(), stira::histogram::HistogramMaster< T >::GetNrOfBins(), stira::imagedata::ArrayGrid< T >::GetValue(), stira::imagedata::ArrayGrid< T >::GetWidth(), stira::histogram::FloatHistogram::InitializeWithNormalizedCumulativeHistogram(), and stira::imagedata::ArrayGrid< T >::SetValue().

double stira::contrastenhance::HistogramTools::MatchHistogramValue	(	double	inValue,
		histogram::IntHistogram *	fhIncomingCumulativeHistogram,
		histogram::FloatHistogram *	fhCumulativeReferenceHistogram
	)

static

matches an intensity from an image with ihIncomingCumulativeHistogram to transform it to ihCumulativeReferenceHistogram

Parameters

inValue	incoming intensity value to be remapped
fhIncomingCumulativeHistogram	incoming cumulative histogram before remapping (not normalized)
fhCumulativeReferenceHistogram	target cumulative histogram after remapping (not normalized)

References stira::common::MathUtils::ClipValue(), stira::histogram::HistogramMaster< T >::GetBinValue(), and stira::histogram::HistogramMaster< T >::GetNrOfBins().

void stira::contrastenhance::HistogramTools::RemapHistogramInROI	(	ArrayGrid< double > *	pInGrid,
		common::RectangularROI< int >	rroi,
		histogram::IntHistogram *	fhCumulativeInput,
		histogram::FloatHistogram *	fhCumulativeReference
	)

static

remap intensities in an image ROI to follow a target histogram References http://en.wikipedia.org/wiki/Histogram_equalization -> Backprojection http://en.wikipedia.org/wiki/Histogram_matching

Parameters

pInGrid	source image grid with intensity values to be remapped
rroi	the rectangular region of interest within which values are to be remapped
ihCumulativeReferenceHistogram	target cumulative histogram after remapping (not normalized)

References stira::common::MathUtils::ClipValue(), stira::common::RectangularROI< T >::GetBottomRightCorner(), stira::imagedata::ArrayGrid< T >::GetHeight(), stira::common::RectangularROI< T >::GetTopLeftCorner(), stira::imagedata::ArrayGrid< T >::GetValue(), stira::imagedata::ArrayGrid< T >::GetWidth(), stira::imagedata::ArrayGrid< T >::SetValue(), stira::common::Point< T >::x, and stira::common::Point< T >::y.

Image * stira::contrastenhance::HistogramTools::RobustLinearRescale	(	Image *	pSourceImage,
		double	lowerFraction = `0.01`,
		double	upperFraction = `0.99`
	)

static

Performs robust linear intensity rescaling, creating a new object as result A new image is created, which becomes the responsability of the caller.

Parameters

pSourceImage	input image
lowerFraction	fraction of darkest pixels to ignore
upperFraction	fraction of pixels to take into account (1-upperFraction is fraction to be discarded)

References stira::imagedata::Image::Clone().

bool stira::contrastenhance::HistogramTools::RobustLinearRescaleNoNew	(	Image *	pSourceImage,
		double	lowerFraction = `0.01`,
		double	upperFraction = `0.99`
	)

static

Performs robust linear intensity rescaling on the image itself, creating no new object (No new image is created; old values are overwritten)

Parameters

pSourceImage	input image; contains result as well
lowerFraction	fraction of darkest pixels to ignore
upperFraction	fraction of pixels to take into account (1-upperFraction is fraction to be discarded)

References stira::common::MathUtils::ClipValue(), stira::imagedata::Image::GetBands(), stira::imagedata::Image::GetHeight(), stira::histogram::IntHistogram::GetLowerBound(), stira::imagedata::GridStatistics< T >::GetMinMax(), stira::imagedata::Image::GetNumberOfBands(), stira::histogram::IntHistogram::GetUpperBound(), stira::imagedata::ArrayGrid< T >::GetValue(), stira::imagedata::Image::GetWidth(), and stira::imagedata::ArrayGrid< T >::SetValue().

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

contrastenhance/contrastenhance/HistogramTools.h
contrastenhance/contrastenhance/HistogramTools.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Member Function Documentation