Class supporting color space conversions from and to CIELab. More...

Static Public Member Functions
static void	dicomLab2RGB (double &R, double &G, double &B, double LDicom, double aDicom, double bDicom)
	Convert CIELab color representation as found in DICOM to sRGB value representation. More...

static void	rgb2DicomLab (double &LDicom, double &aDicom, double &bDicom, double R, double G, double B)
	Convert sRGB color representation to CIELab color representation as found in DICOM. More...

static void	dicomlab2Lab (double &L, double &a, double &b, double LDicom, double aDicom, double bDicom)
	Convert CIELab color representation as found in DICOM to CIELab representation. More...

static void	lab2DicomLab (double &LDicom, double &aDicom, double &bDicom, double L, double a, double b)
	Convert CIELab color representation to CIELab color representation found in DICOM. More...

static void	rgb2Lab (double &L, double &a, double &b, double R, double G, double B)
	Convert sRGB color representation to CIELab representation. More...

static void	rgb2Xyz (double &X, double &Y, double &Z, double R, double G, double B)
	Convert sRGB color representation to CIE XYZ representation. More...

static void	xyz2Lab (double &L, double &a, double &b, double X, double Y, double Z)
	Convert CIELAB XYZ color representation to CIELab representation. More...

static void	lab2Rgb (double &R, double &G, double &B, double L, double a, double b)
	Convert CIELab color representation to sRGB representation. More...

static void	lab2Xyz (double &X, double &Y, double &Z, double L, double a, double b)
	Convert CIELab color representation to CIE XYZ representation. More...

static void	xyz2Rgb (double &R, double &G, double &B, double X, double Y, double Z)
	Convert CIE XYZ color representation to sRGB representation. More...

Static Public Attributes
static const double	D65_WHITEPOINT_X
	D65 standard lightpoint X component for conversion from CIEXYZ to CIELab.

static const double	D65_WHITEPOINT_Y
	D65 standard lightpoint Y component for conversion from CIEXYZ to CIELab.

static const double	D65_WHITEPOINT_Z
	D65 standard lightpoint Z component for conversion from CIEXYZ to CIELab.

Static Protected Member Functions
static double	gammaCorrection (double n)
	Perform sRGB gamma correction, transforms R to R'. More...

static double	invGammaCorrection (double n)
	Perform inverse sRGB gamma correction, transforms R' to R. More...

static double	labf (double n)
	CIE Lab* f function (used to convert XYZ to Lab*) More...

static double	labfInv (double n)
	CIE Lab* inverse f function. More...

static double	min2 (double a, double b)
	Get the minimum of two numbers. More...

static double	min3 (double a, double b, double c)
	Get the minimum of three numbers. More...

Detailed Description

Class supporting color space conversions from and to CIELab.

In some IODs DICOM stores CIELab color values which must often be converted to RGB for display or other purposes. This is supported by the functions dicomLab2RGB() and rgb2DicomLab(). The CIELab value range in DICOM is [0,65535] for all three values. The RGB value range in this class is [0;1]. Further functions are available in order to convert between RGB, "normal" CIELab value range as well as CIEXYZ. The class uses double floating point precision for calculations.

Member Function Documentation

static void IODCIELabUtil::dicomlab2Lab	(	double &	L,
		double &	a,
		double &	b,
		double	LDicom,
		double	aDicom,
		double	bDicom
	)

static

Convert CIELab color representation as found in DICOM to CIELab representation.

See DICOM part 3 for details.

Parameters

L	Output CIELab luminance component with 0 <= L <= 100
a	Output CIELab "a" component (red<->green) with -127 <= a <= 128
b	Output CIELab "b" component (blue<->yellow) with -127 <= b <= 128
LDicom	Input CIELab luminance component with 0 <= L <= 65535 as found in DICOM
aDicom	Input CIELab "a" component (red<->green) with 0 <= a <= 65535 as found in DICOM
bDicom	Input CIELab "b" component (blue<->yellow) with 0 <= b <= 65535 as found in DICOM

static void IODCIELabUtil::dicomLab2RGB	(	double &	R,
		double &	G,
		double &	B,
		double	LDicom,
		double	aDicom,
		double	bDicom
	)

static

Convert CIELab color representation as found in DICOM to sRGB value representation.

See DICOM part 3 for details.

Parameters

R	Output sRGB "R" component (red) with 0 <= R <= 1
G	Output sRGB "G" component (green) with 0 <= G <= 1
B	Output sRGB "R" component (blue) with 0 <= B <= 1
LDicom	Input DICOM CIELab luminance component with 0 <= L <= 65535
aDicom	Input DICOM CIELab "a" component (red<->green) with 0 <= a <= 65535
bDicom	Input DIOCM CIELab "b" component (blue<->yellow) with 0 <= a <= 65535

static double IODCIELabUtil::gammaCorrection ( double n )

staticprotected

Perform sRGB gamma correction, transforms R to R'.

Parameters

n	The value to correct

Returns: The gamma-corrected value

static double IODCIELabUtil::invGammaCorrection ( double n )

staticprotected

Perform inverse sRGB gamma correction, transforms R' to R.

Parameters

n	The value to invert

Returns: The gamma-inverted value

static void IODCIELabUtil::lab2DicomLab	(	double &	LDicom,
		double &	aDicom,
		double &	bDicom,
		double	L,
		double	a,
		double	b
	)

static

Convert CIELab color representation to CIELab color representation found in DICOM.

See DICOM part 3 for details.

Parameters

LDicom	Output CIELab luminance component with 0 <= L <= 65535 as found in DICOM
aDicom	Output CIELab "a" component (red<->green) with 0 <= a <= 65535 as found in DICOM
bDicom	Output CIELab "b" component (blue<->yellow) with 0 <= b <= 65535 as found in DICOM
L	Input CIELab luminance component with 0 <= L <= 100
a	Input CIELab "a" component (red<->green) with -127 <= a <= 128
b	Input CIELab "b" component (blue<->yellow) with -127 <= b <= 128

static void IODCIELabUtil::lab2Rgb	(	double &	R,
		double &	G,
		double &	B,
		double	L,
		double	a,
		double	b
	)

static

Convert CIELab color representation to sRGB representation.

Parameters

R	Output sRGB "R" component (red) with 0 <= R <= 1
G	Output sRGB "G" component (green) with 0 <= G <= 1
B	Output sRGB "R" component (blue) with 0 <= B <= 1
L	Input CIELab luminance component with 0 <= L <= 100
a	Input CIELab "a" component (red<->green) with -127 <= a <= 128
b	Input CIELab "b" component (blue<->yellow) with -127 <= b <= 128

static void IODCIELabUtil::lab2Xyz	(	double &	X,
		double &	Y,
		double &	Z,
		double	L,
		double	a,
		double	b
	)

static

Convert CIELab color representation to CIE XYZ representation.

Parameters

X	Output CIELab XYZ "X" component with 0 <= X <= 1
Y	Output CIELab XYZ "Y" component with 0 <= Y <= 1
Z	Output CIELab XYZ "Z" component with 0 <= Z <= 1
L	Input CIELab luminance component with 0 <= L <= 100
a	Input CIELab "a" component (red<->green) with -127 <= a <= 128
b	Input CIELab "b" component (blue<->yellow) with -127 <= b <= 128

static double IODCIELabUtil::labf ( double n )

staticprotected

CIE L*a*b* f function (used to convert XYZ to L*a*b*)

Parameters

n	value to convert

Returns: The converted value

static double IODCIELabUtil::labfInv ( double n )

staticprotected

CIE L*a*b* inverse f function.

Parameters

n	The value to compute the inverse for

Returns: The resulting inverse

static double IODCIELabUtil::min2	(	double	a,
		double	b
	)

staticprotected

Get the minimum of two numbers.

Parameters

a	First number
b	Second number

Returns: The minimum of a, b. a if a and b are equal.

static double IODCIELabUtil::min3	(	double	a,
		double	b,
		double	c
	)

staticprotected

Get the minimum of three numbers.

Parameters

a	First number
b	Second number
c	Third number

Returns: The minimum of a, b and c. If a value occurs more than once, then preference order then a is preferred if possible, b otherwise

static void IODCIELabUtil::rgb2DicomLab	(	double &	LDicom,
		double &	aDicom,
		double &	bDicom,
		double	R,
		double	G,
		double	B
	)

static

Convert sRGB color representation to CIELab color representation as found in DICOM.

See DICOM part 3 for details.

Parameters

LDicom	Output CIELab luminance component with 0 <= L <= 65535 as found in DICOM
aDicom	Output CIELab "a" component (red<->green) with 0 <= a <= 65535 as found in DICOM
bDicom	Output CIELab "b" component (blue<->yellow) with 0 <= b <= 65535 as found in DICOM
R	Input sRGB "R" component (red) with 0 <= R <= 1
G	Input sRGB "G" component (green) with 0 <= G <= 1
B	Input sRGB "R" component (blue) with 0 <= B <= 1

static void IODCIELabUtil::rgb2Lab	(	double &	L,
		double &	a,
		double &	b,
		double	R,
		double	G,
		double	B
	)

static

Convert sRGB color representation to CIELab representation.

Parameters

L	Output CIELab luminance component with 0 <= L <= 100
a	Output CIELab "a" component (red<->green) with -127 <= a <= 128
b	Output CIELab "b" component (blue<->yellow) with -127 <= b <= 128
R	Input sRGB "R" component (red) with 0 <= R <= 1
G	Input sRGB "G" component (green) with 0 <= G <= 1
B	Input sRGB "R" component (blue) with 0 <= B <= 1

static void IODCIELabUtil::rgb2Xyz	(	double &	X,
		double &	Y,
		double &	Z,
		double	R,
		double	G,
		double	B
	)

static

Convert sRGB color representation to CIE XYZ representation.

Parameters

X	Output CIELab XYZ "X" component with 0 <= X <= 1
Y	Output CIELab XYZ "Y" component with 0 <= Y <= 1
Z	Output CIELab XYZ "Z" component with 0 <= Z <= 1
R	Input sRGB "R" component (red) with 0 <= R <= 1
G	Input sRGB "G" component (green) with 0 <= G <= 1
B	Input sRGB "R" component (blue) with 0 <= B <= 1

static void IODCIELabUtil::xyz2Lab	(	double &	L,
		double &	a,
		double &	b,
		double	X,
		double	Y,
		double	Z
	)

static

Convert CIELAB XYZ color representation to CIELab representation.

Parameters

L	Output CIELab luminance component with 0 <= L <= 100
a	Output CIELab "a" component (red<->green) with -127 <= a <= 128
b	Output CIELab "b" component (blue<->yellow) with -127 <= b <= 128
X	Input CIELab XYZ "X" component with 0 <= X <= 1
Y	Input CIELab XYZ "Y" component with 0 <= Y <= 1
Z	Input CIELab XYZ "Z" component with 0 <= Z <= 1

static void IODCIELabUtil::xyz2Rgb	(	double &	R,
		double &	G,
		double &	B,
		double	X,
		double	Y,
		double	Z
	)

static

Convert CIE XYZ color representation to sRGB representation.

Parameters

R	Output sRGB "R" component (red) with 0 <= R <= 1
G	Output sRGB "G" component (green) with 0 <= G <= 1
B	Output sRGB "R" component (blue) with 0 <= B <= 1
X	Output CIELab XYZ "X" component with 0 <= X <= 1
Y	Output CIELab XYZ "Y" component with 0 <= Y <= 1
Z	Output CIELab XYZ "Z" component with 0 <= Z <= 1

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

dcmiod/include/dcmtk/dcmiod/cielabutil.h

Static Public Member Functions

Static Public Attributes

Static Protected Member Functions

Detailed Description

Member Function Documentation