#include <KoColorimetryUtils.h>

Public Member Functions
QMatrix4x4	absoluteColorimetricTo (const Colorimetry &other) const

Colorimetry	adaptedTo (xyY newWhitepoint) const

const XYZ &	blue () const

	Colorimetry (xy red, xy green, xy blue, xy white)

	Colorimetry (xyY red, xyY green, xyY blue, xyY white)

	Colorimetry (XYZ red, XYZ green, XYZ blue, XYZ white)

QMatrix4x4	fromLMS () const

const QMatrix4x4 &	fromXYZ () const

const XYZ &	green () const

Colorimetry	interpolateGamutTo (const Colorimetry &one, double factor) const

bool	operator== (const Colorimetry &other) const

const XYZ &	red () const

QMatrix4x4	relativeColorimetricTo (const Colorimetry &other) const

QMatrix4x4	toLMS () const

const QMatrix4x4 &	toXYZ () const

const XYZ &	white () const

Colorimetry	withWhitepoint (xyY newWhitePoint) const

Static Public Member Functions
static QMatrix4x4	calculateToXYZMatrix (XYZ red, XYZ green, XYZ blue, XYZ white)

static QMatrix4x4	chromaticAdaptationMatrix (XYZ sourceWhitepoint, XYZ destinationWhitepoint)

static bool	isReal (xy red, xy green, xy blue, xy white)

static bool	isValid (xy red, xy green, xy blue, xy white)

Static Public Attributes
static const Colorimetry	AdobeRGB

static const Colorimetry	BT2020

static const Colorimetry	BT709

static const Colorimetry	CIEXYZ

static const Colorimetry	DCIP3

static const Colorimetry	DisplayP3

static const Colorimetry	GenericFilm

static const Colorimetry	NTSC

static const Colorimetry	PAL

static const Colorimetry	PAL_M

Private Attributes
XYZ	m_blue

QMatrix4x4	m_fromXYZ

XYZ	m_green

XYZ	m_red

QMatrix4x4	m_toXYZ

XYZ	m_white

Detailed Description

Describes the definition of colors in a color space. Red, green and blue define the chromaticities ("absolute colors") of the red, green and blue LEDs on a display in xy coordinates White defines the the chromaticity of the reference white in xy coordinates

Definition at line 70 of file KoColorimetryUtils.h.

Constructor & Destructor Documentation

◆ Colorimetry() [1/3]

KoColorimetryUtils::Colorimetry::Colorimetry	(	XYZ	red,
		XYZ	green,
		XYZ	blue,
		XYZ	white )

explicit

Definition at line 247 of file KoColorimetryUtils.cpp.

    : m_red(red)
    , m_green(green)
    , m_blue(blue)
    , m_white(white)
    , m_toXYZ(calculateToXYZMatrix(red, green, blue, white))
    , m_fromXYZ(m_toXYZ.inverted())
{
}

◆ Colorimetry() [2/3]

KoColorimetryUtils::Colorimetry::Colorimetry	(	xyY	red,
		xyY	green,
		xyY	blue,
		xyY	white )

explicit

Definition at line 257 of file KoColorimetryUtils.cpp.

    : Colorimetry(red.toXYZ(), green.toXYZ(), blue.toXYZ(), white.toXYZ())
{
}

◆ Colorimetry() [3/3]

KoColorimetryUtils::Colorimetry::Colorimetry	(	xy	red,
		xy	green,
		xy	blue,
		xy	white )

explicit

Definition at line 262 of file KoColorimetryUtils.cpp.

    : m_white(xyY{white.x, white.y, 1.0}.toXYZ())
{
    const auto brightness = (matrixFromColumns(xyY{red.x, red.y, 1.0}.toXYZ().asVector(),
                                               xyY{green.x, green.y, 1.0}.toXYZ().asVector(),
                                               xyY{blue.x, blue.y, 1.0}.toXYZ().asVector()))
                                .inverted().map(
        xyY{white.x, white.y, 1.0}.toXYZ().asVector());
    m_red = xyY{red.x, red.y, brightness.x()}.toXYZ();
    m_green = xyY{green.x, green.y, brightness.y()}.toXYZ();
    m_blue = xyY{blue.x, blue.y, brightness.z()}.toXYZ();
    m_toXYZ = calculateToXYZMatrix(m_red, m_green, m_blue, m_white);
    m_fromXYZ = m_toXYZ.inverted();
}

References KoColorimetryUtils::XYZ::asVector(), blue(), calculateToXYZMatrix(), green(), m_blue, m_fromXYZ, m_green, m_red, m_toXYZ, m_white, KoColorimetryUtils::matrixFromColumns(), red(), and white().

Member Function Documentation

◆ absoluteColorimetricTo()

QMatrix4x4 KoColorimetryUtils::Colorimetry::absoluteColorimetricTo ( const Colorimetry & other ) const

Definition at line 340 of file KoColorimetryUtils.cpp.

{
    return other.fromXYZ() * toXYZ();
}

References fromXYZ(), and toXYZ().

◆ adaptedTo()

Colorimetry KoColorimetryUtils::Colorimetry::adaptedTo ( xyY newWhitepoint ) const

Returns: this colorimetry, adapted to the new whitepoint using the Bradford transform

Definition at line 313 of file KoColorimetryUtils.cpp.

{
    const auto mat = chromaticAdaptationMatrix(this->white(), newWhitepoint.toXYZ());
    return Colorimetry{
        XYZ::fromVector(mat.map(red().asVector())),
        XYZ::fromVector(mat.map(green().asVector())),
        XYZ::fromVector(mat.map(blue().asVector())),
        newWhitepoint.toXYZ(),
    };
}

References blue(), chromaticAdaptationMatrix(), KoColorimetryUtils::XYZ::fromVector(), green(), red(), KoColorimetryUtils::xyY::toXYZ(), and white().

◆ blue()

const XYZ & KoColorimetryUtils::Colorimetry::blue ( ) const

Definition at line 360 of file KoColorimetryUtils.cpp.

{
    return m_blue;
}

References m_blue.

◆ calculateToXYZMatrix()

QMatrix4x4 KoColorimetryUtils::Colorimetry::calculateToXYZMatrix	(	XYZ	red,
		XYZ	green,
		XYZ	blue,
		XYZ	white )

static

Definition at line 188 of file KoColorimetryUtils.cpp.

{
    const QVector3D r = red.asVector();
    const QVector3D g = green.asVector();
    const QVector3D b = blue.asVector();
    const auto component_scale = (matrixFromColumns(r, g, b)).inverted().map(white.asVector());
    return matrixFromColumns(r * component_scale.x(), g * component_scale.y(), b * component_scale.z());
}

References KoColorimetryUtils::XYZ::asVector(), blue(), green(), KoColorimetryUtils::matrixFromColumns(), red(), and white().

◆ chromaticAdaptationMatrix()

QMatrix4x4 KoColorimetryUtils::Colorimetry::chromaticAdaptationMatrix	(	XYZ	sourceWhitepoint,
		XYZ	destinationWhitepoint )

static

Returns: a matrix adapting XYZ values from the source whitepoint to the destination whitepoint with the Bradford transform

Definition at line 149 of file KoColorimetryUtils.cpp.

{
    static const QMatrix4x4 bradford = []() {
        QMatrix4x4 ret;
        ret(0, 0) = 0.8951;
        ret(0, 1) = 0.2664;
        ret(0, 2) = -0.1614;
        ret(1, 0) = -0.7502;
        ret(1, 1) = 1.7135;
        ret(1, 2) = 0.0367;
        ret(2, 0) = 0.0389;
        ret(2, 1) = -0.0685;
        ret(2, 2) = 1.0296;
        return ret;
    }();
    static const QMatrix4x4 inverseBradford = []() {
        QMatrix4x4 ret;
        ret(0, 0) = 0.9869929;
        ret(0, 1) = -0.1470543;
        ret(0, 2) = 0.1599627;
        ret(1, 0) = 0.4323053;
        ret(1, 1) = 0.5183603;
        ret(1, 2) = 0.0492912;
        ret(2, 0) = -0.0085287;
        ret(2, 1) = 0.0400428;
        ret(2, 2) = 0.9684867;
        return ret;
    }();
    if (sourceWhitepoint == destinationWhitepoint) {
        return QMatrix4x4{};
    }
    const QVector3D factors = (bradford.map(destinationWhitepoint.asVector())) / (bradford.map(sourceWhitepoint.asVector()));
    QMatrix4x4 adaptation{};
    adaptation(0, 0) = factors.x();
    adaptation(1, 1) = factors.y();
    adaptation(2, 2) = factors.z();
    return inverseBradford * adaptation * bradford;
}

References KoColorimetryUtils::XYZ::asVector().

◆ fromLMS()

QMatrix4x4 KoColorimetryUtils::Colorimetry::fromLMS ( ) const

Definition at line 308 of file KoColorimetryUtils.cpp.

{
    return m_fromXYZ * s_inverseDolbyLMS;
}

References m_fromXYZ, and KoColorimetryUtils::s_inverseDolbyLMS.

◆ fromXYZ()

const QMatrix4x4 & KoColorimetryUtils::Colorimetry::fromXYZ ( ) const

Returns: a matrix that transforms from the XYZ representation to the linear RGB representation of colors in this colorimetry

Definition at line 282 of file KoColorimetryUtils.cpp.

{
    return m_fromXYZ;
}

References m_fromXYZ.

◆ green()

const XYZ & KoColorimetryUtils::Colorimetry::green ( ) const

Definition at line 355 of file KoColorimetryUtils.cpp.

{
    return m_green;
}

References m_green.

◆ interpolateGamutTo()

Colorimetry KoColorimetryUtils::Colorimetry::interpolateGamutTo	(	const Colorimetry &	one,
		double	factor ) const

interpolates the primaries depending on the passed factor. The whitepoint stays unchanged

Definition at line 197 of file KoColorimetryUtils.cpp.

{
    return Colorimetry{
        m_red * (1 - factor) + one.red() * factor,
        m_green * (1 - factor) + one.green() * factor,
        m_blue * (1 - factor) + one.blue() * factor,
        m_white, // whitepoint should stay the same
    };
}

References blue(), green(), m_blue, m_green, m_red, m_white, and red().

◆ isReal()

bool KoColorimetryUtils::Colorimetry::isReal	(	xy	red,
		xy	green,
		xy	blue,
		xy	white )

static

checks if the colorimetry could be from a real display

Definition at line 233 of file KoColorimetryUtils.cpp.

{
    if (!isValid(red, green, blue, white)) {
        return false;
    }
    // outside of XYZ definitely can't be shown on a display
    // TODO maybe calculate if all values are within the human-visible gamut too?
    if (red.x < 0 || red.x > 1 || red.y < 0 || red.y > 1 || green.x < 0 || green.x > 1 || green.y < 0 || green.y > 1 || blue.x < 0 || blue.x > 1 || blue.y < 0
        || blue.y > 1 || white.x < 0 || white.x > 1 || white.y < 0 || white.y > 1) {
        return false;
    }
    return true;
}

References blue(), green(), isValid(), red(), and white().

◆ isValid()

bool KoColorimetryUtils::Colorimetry::isValid	(	xy	red,
		xy	green,
		xy	blue,
		xy	white )

static

checks if the colorimetry is sane and won't cause crashes or glitches

Definition at line 212 of file KoColorimetryUtils.cpp.

{
    // this is more of a heuristic than a hard rule
    // but if the gamut is too small, it's not really usable
    const double gamutArea = triangleArea(red.asVector(), green.asVector(), blue.asVector());
    if (gamutArea < 0.02) {
        return false;
    }
    // if the white point is inside the gamut triangle,
    // the three triangles made up between the primaries and the whitepoint
    // must have the same area as the gamut triangle
    const double area1 = triangleArea(white.asVector(), green.asVector(), blue.asVector());
    const double area2 = triangleArea(red.asVector(), white.asVector(), blue.asVector());
    const double area3 = triangleArea(red.asVector(), green.asVector(), white.asVector());
    if (std::abs(area1 + area2 + area3 - gamutArea) > 0.001) {
        // this would cause terrible glitches
        return false;
    }
    return true;
}

References KoColorimetryUtils::XYZ::asVector(), blue(), green(), red(), KoColorimetryUtils::triangleArea(), and white().

◆ operator==()

bool KoColorimetryUtils::Colorimetry::operator== ( const Colorimetry & other ) const

Definition at line 345 of file KoColorimetryUtils.cpp.

{
    return red() == other.red() && green() == other.green() && blue() == other.blue() && white() == other.white();
}

References blue(), green(), red(), and white().

◆ red()

const XYZ & KoColorimetryUtils::Colorimetry::red ( ) const

Definition at line 350 of file KoColorimetryUtils.cpp.

{
    return m_red;
}

References m_red.

◆ relativeColorimetricTo()

QMatrix4x4 KoColorimetryUtils::Colorimetry::relativeColorimetricTo ( const Colorimetry & other ) const

Definition at line 335 of file KoColorimetryUtils.cpp.

{
    return other.fromXYZ() * chromaticAdaptationMatrix(white(), other.white()) * toXYZ();
}

References chromaticAdaptationMatrix(), fromXYZ(), toXYZ(), and white().

◆ toLMS()

QMatrix4x4 KoColorimetryUtils::Colorimetry::toLMS ( ) const

Definition at line 303 of file KoColorimetryUtils.cpp.

{
    return s_xyzToDolbyLMS * m_toXYZ;
}

References m_toXYZ, and KoColorimetryUtils::s_xyzToDolbyLMS.

◆ toXYZ()

const QMatrix4x4 & KoColorimetryUtils::Colorimetry::toXYZ ( ) const

Returns: a matrix that transforms from the linear RGB representation of colors in this colorimetry to the XYZ representation

Definition at line 277 of file KoColorimetryUtils.cpp.

{
    return m_toXYZ;
}

References m_toXYZ.

◆ white()

const XYZ & KoColorimetryUtils::Colorimetry::white ( ) const

Definition at line 365 of file KoColorimetryUtils.cpp.

{
    return m_white;
}

References m_white.

◆ withWhitepoint()

Colorimetry KoColorimetryUtils::Colorimetry::withWhitepoint ( xyY newWhitePoint ) const

replaces the current whitepoint with the new one this does not do whitepoint adaptation!

Definition at line 324 of file KoColorimetryUtils.cpp.

{
    newWhitePoint.Y = 1;
    return Colorimetry{
        m_red,
        m_green,
        m_blue,
        newWhitePoint.toXYZ(),
    };
}

References m_blue, m_green, m_red, KoColorimetryUtils::xyY::toXYZ(), and KoColorimetryUtils::xyY::Y.

Member Data Documentation

◆ AdobeRGB

const Colorimetry KoColorimetryUtils::Colorimetry::AdobeRGB

static

Initial value:

= Colorimetry{
    xy{0.6400, 0.3300},
    xy{0.2100, 0.7100},
    xy{0.1500, 0.0600},
    xy{0.3127, 0.3290},
}

Definition at line 82 of file KoColorimetryUtils.h.

◆ BT2020

const Colorimetry KoColorimetryUtils::Colorimetry::BT2020

static

Initial value:

= Colorimetry{
    xy{0.708, 0.292},
    xy{0.170, 0.797},
    xy{0.131, 0.046},
    xy{0.3127, 0.3290},
}

Definition at line 78 of file KoColorimetryUtils.h.

◆ BT709

const Colorimetry KoColorimetryUtils::Colorimetry::BT709

static

Initial value:

= Colorimetry{
    xy{0.64, 0.33},
    xy{0.30, 0.60},
    xy{0.15, 0.06},
    xy{0.3127, 0.3290},
}

Definition at line 73 of file KoColorimetryUtils.h.

◆ CIEXYZ

const Colorimetry KoColorimetryUtils::Colorimetry::CIEXYZ

static

Initial value:

= Colorimetry{
    XYZ{1.0, 0.0, 0.0},
    XYZ{0.0, 1.0, 0.0},
    XYZ{0.0, 0.0, 1.0},
    xy{1.0 / 3.0, 1.0 / 3.0}.toXYZ(),
}

Definition at line 79 of file KoColorimetryUtils.h.

◆ DCIP3

const Colorimetry KoColorimetryUtils::Colorimetry::DCIP3

static

Initial value:

= Colorimetry{
    xy{0.680, 0.320},
    xy{0.265, 0.690},
    xy{0.150, 0.060},
    xy{0.314, 0.351},
}

Definition at line 80 of file KoColorimetryUtils.h.

◆ DisplayP3

const Colorimetry KoColorimetryUtils::Colorimetry::DisplayP3

static

Initial value:

= Colorimetry{
    xy{0.680, 0.320},
    xy{0.265, 0.690},
    xy{0.150, 0.060},
    xy{0.3127, 0.3290},
}

Definition at line 81 of file KoColorimetryUtils.h.

◆ GenericFilm

const Colorimetry KoColorimetryUtils::Colorimetry::GenericFilm

static

Initial value:

= Colorimetry{
    xy{0.681, 0.319},
    xy{0.243, 0.692},
    xy{0.145, 0.049},
    xy{0.310, 0.316},
}

Definition at line 77 of file KoColorimetryUtils.h.

◆ m_blue

XYZ KoColorimetryUtils::Colorimetry::m_blue

private

Definition at line 141 of file KoColorimetryUtils.h.

◆ m_fromXYZ

QMatrix4x4 KoColorimetryUtils::Colorimetry::m_fromXYZ

private

Definition at line 144 of file KoColorimetryUtils.h.

◆ m_green

XYZ KoColorimetryUtils::Colorimetry::m_green

private

Definition at line 140 of file KoColorimetryUtils.h.

◆ m_red

XYZ KoColorimetryUtils::Colorimetry::m_red

private

Definition at line 139 of file KoColorimetryUtils.h.

◆ m_toXYZ

QMatrix4x4 KoColorimetryUtils::Colorimetry::m_toXYZ

private

Definition at line 143 of file KoColorimetryUtils.h.

◆ m_white

XYZ KoColorimetryUtils::Colorimetry::m_white

private

Definition at line 142 of file KoColorimetryUtils.h.

◆ NTSC

const Colorimetry KoColorimetryUtils::Colorimetry::NTSC

static

Initial value:

= Colorimetry{
    xy{0.630, 0.340},
    xy{0.310, 0.595},
    xy{0.155, 0.070},
    xy{0.3127, 0.3290},
}

Definition at line 76 of file KoColorimetryUtils.h.

◆ PAL

const Colorimetry KoColorimetryUtils::Colorimetry::PAL

static

Initial value:

= Colorimetry{
    xy{0.640, 0.330},
    xy{0.290, 0.600},
    xy{0.150, 0.060},
    xy{0.3127, 0.3290},
}

Definition at line 75 of file KoColorimetryUtils.h.

◆ PAL_M

const Colorimetry KoColorimetryUtils::Colorimetry::PAL_M

static

Initial value:

= Colorimetry{
    xy{0.67, 0.33},
    xy{0.21, 0.71},
    xy{0.14, 0.08},
    xy{0.310, 0.316},
}

Definition at line 74 of file KoColorimetryUtils.h.

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

libs/pigment/KoColorimetryUtils.h
libs/pigment/KoColorimetryUtils.cpp

Public Member Functions

Static Public Member Functions

Static Public Attributes

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Colorimetry() [1/3]

◆ Colorimetry() [2/3]

◆ Colorimetry() [3/3]

Member Function Documentation

◆ absoluteColorimetricTo()

◆ adaptedTo()

◆ blue()

◆ calculateToXYZMatrix()

◆ chromaticAdaptationMatrix()

◆ fromLMS()

◆ fromXYZ()

◆ green()

◆ interpolateGamutTo()

◆ isReal()

◆ isValid()

◆ operator==()

◆ red()

◆ relativeColorimetricTo()

◆ toLMS()

◆ toXYZ()

◆ white()

◆ withWhitepoint()

Member Data Documentation

◆ AdobeRGB

◆ BT2020

◆ BT709

◆ CIEXYZ

◆ DCIP3

◆ DisplayP3

◆ GenericFilm

◆ m_blue

◆ m_fromXYZ

◆ m_green

◆ m_red

◆ m_toXYZ

◆ m_white

◆ NTSC

◆ PAL

◆ PAL_M