qualpal::colors::Lab Class Reference

Lab color space representation (CIE L*a*b*). More...

#include <colors.h>

Public Member Functions
	Lab ()
	Default constructor initializes Lab to black (0,0,0)
	Lab (const double l, const double a, const double b)
	Construct Lab from component values.
	Lab (const RGB &rgb)
	Construct Lab from RGB color.
	Lab (const HSL &hsl)
	Construct Lab from HSL color.
	Lab (const XYZ &xyz, const std::array< double, 3 > &white_point={ 0.95047, 1, 1.08883 })
	Construct Lab from XYZ color.
	Lab (const LCHab &lch)
	Construct Lab from LCHab color.
bool	operator== (const Lab &other) const
	Equality operator for Lab colors.
double	l () const
	Get lightness [0,100].
double	a () const
	Get green-red component.
double	b () const
	Get blue-yellow component.

Detailed Description

Lab color space representation (CIE L*a*b*).

Perceptually uniform color space where Euclidean distance approximates perceived color difference.

• L: Lightness [0, 100] (0 = black, 100 = white)
• a: Green-red axis [-128, 127] (negative = green, positive = red)
• b: Blue-yellow axis [-128, 127] (negative = blue, positive = yellow)

Provides conversion constructors for RGB, HSL, XYZ, and LCHab. Most conversions use the D65 reference white point by default.

See also

RGB, HSL, XYZ, LCHab for conversions.

Definition at line 492 of file colors.h.

Constructor & Destructor Documentation

Lab() [1/5]

qualpal::colors::Lab::Lab	(	const double	l,
		const double	a,
		const double	b
	)

Construct Lab from component values.

Parameters

l	Lightness [0,100]
a	Green-red axis [-128,127]
b	Blue-yellow axis [-128,127]

Lab() [2/5]

qualpal::colors::Lab::Lab

(

const RGB &

rgb

)

Construct Lab from RGB color.

Parameters

rgb	RGB color to convert from

Lab() [3/5]

qualpal::colors::Lab::Lab

(

const HSL &

hsl

)

Construct Lab from HSL color.

Parameters

hsl	HSL color to convert from

Lab() [4/5]

qualpal::colors::Lab::Lab	(	const XYZ &	xyz,
		const std::array< double, 3 > &	white_point = { 0.95047, 1, 1.08883 }
	)

Construct Lab from XYZ color.

Parameters

xyz	XYZ color to convert from
white_point	Reference white point (default: D65)

Lab() [5/5]

qualpal::colors::Lab::Lab

(

const LCHab &

lch

)

Construct Lab from LCHab color.

Parameters

lch	LCHab color to convert from

Member Function Documentation

a()

double qualpal::colors::Lab::a ( ) const

inline

Get green-red component.

Definition at line 553 of file colors.h.

b()

double qualpal::colors::Lab::b ( ) const

inline

Get blue-yellow component.

Definition at line 555 of file colors.h.

l()

double qualpal::colors::Lab::l ( ) const

inline

Get lightness [0,100].

Definition at line 551 of file colors.h.

operator==()

bool qualpal::colors::Lab::operator== ( const Lab &  other ) const

inline

Equality operator for Lab colors.

Parameters

other

Other Lab color to compare with

Returns

true if both Lab colors are equal, false otherwise

Definition at line 544 of file colors.h.

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

• include/qualpal/colors.h