icmm::IWhitePointProvider Class Reference

Interface providing white point information for color spaces. More...

#include <IWhitePointProvider.h>

Inheritance diagram for icmm::IWhitePointProvider:

Public Member Functions
virtual icmm::CVarColor	GetWhitePoint () const =0
	Gets the white point as a color value.
Public Member Functions inherited from istd::IChangeable
virtual int	GetSupportedOperations () const
	Get set of flags for supported operations.
virtual bool	CopyFrom (const IChangeable &object, CompatibilityMode mode=CM_WITHOUT_REFS)
	Copy this object from another one.
virtual bool	IsEqual (const IChangeable &object) const
	Compare this object with another object.
virtual istd::TUniqueInterfacePtr< istd::IChangeable >	CloneMe (CompatibilityMode mode=CM_WITHOUT_REFS) const
	Make a copy of this object.
virtual bool	ResetData (CompatibilityMode mode=CM_WITHOUT_REFS)
	Reset data to its default state.
virtual void	BeginChanges (const ChangeSet &changeSet)
	Starts the change transaction.
virtual void	EndChanges (const ChangeSet &changeSet)
	Ends the change transaction.
virtual void	BeginChangeGroup (const ChangeSet &changeSet)
	Starts group of changes.
virtual void	EndChangeGroup (const ChangeSet &changeSet)
	Ends group of changes.
Public Member Functions inherited from istd::IPolymorphic
virtual	~IPolymorphic ()

Additional Inherited Members
Public Types inherited from istd::IChangeable
enum	ChangeFlags {   CF_ACF_INTERNAL = 0 , CF_ALL_DATA , CF_ANY , CF_DESTROYING ,   CF_DELEGATED , CF_NO_UNDO }
	Data model change notification flags. More...
enum	SupportedOperations {   SO_NONE = 0 , SO_OBSERVE = 1 << 0 , SO_COPY = 1 << 1 , SO_CLONE = 1 << 2 ,   SO_COMPARE = 1 << 3 , SO_RESET = 1 << 4 }
	Flags for supported operations. More...
enum	CompatibilityMode { CM_STRICT , CM_WITHOUT_REFS , CM_WITH_REFS , CM_CONVERT }
	Control how relationship betweeen objects are interpreted. More...
typedef QMultiMap< QByteArray, QVariant >	ChangeInfoMap
Static Public Member Functions inherited from istd::IChangeable
static const ChangeSet &	GetNoChanges ()
	Get empty set of changes.
static const ChangeSet &	GetAnyChange ()
	Get anonymous change set.
static const ChangeSet &	GetAllChanges ()
	Get anonymous change set.
static const ChangeSet &	GetDelegatedChanges ()
	Get delegated change set.
Protected Member Functions inherited from istd::IChangeable
virtual void	OnBeginChanges ()
	Callback function for begin change event.
virtual void	OnEndChanges (const ChangeSet &changeSet)
	Callback function for end change event.

Detailed Description

Interface providing white point information for color spaces.

Purpose

IWhitePointProvider defines an interface for objects that supply white point information. The white point represents the color that should appear as "white" in a color space, and is essential for chromatic adaptation and color space conversions. Different viewing conditions and illuminants produce different white points (D65, D50, A, etc.).

White Point Concept

A white point defines:

• Reference White: The color considered as "neutral" or "white"
• Illuminant: The light source characteristics (daylight, tungsten, etc.)
• Adaptation: How colors appear under different lighting conditions
• XYZ Coordinates: Typically expressed as XYZ tristimulus values

Standard Illuminants

Common standard white points:

• D65: Daylight at 6500K - standard for sRGB, most displays
• D50: Daylight at 5000K - standard for printing (ICC profiles)
• A: Tungsten lamp at 2856K - incandescent lighting
• F2: Cool white fluorescent - office lighting
• E: Equal energy - theoretical reference

Usage Examples

// Example 1: Getting white point from provider
void InspectWhitePoint(const icmm::IWhitePointProvider* provider)
{
       icmm::CVarColor whitePoint = provider->GetWhitePoint();
       
       // White point typically in XYZ coordinates
       if (whitePoint.GetElementsCount() >= 3) {
              double X = whitePoint.GetElement(0);
              double Y = whitePoint.GetElement(1);
              double Z = whitePoint.GetElement(2);
              
              qDebug() << "White Point XYZ:" << X << Y << Z;
       }
}
 
// Example 2: Comparing white points
bool SameWhitePoint(const icmm::IWhitePointProvider* provider1,
                   const icmm::IWhitePointProvider* provider2,
                   double tolerance = 0.001)
{
       icmm::CVarColor wp1 = provider1->GetWhitePoint();
       icmm::CVarColor wp2 = provider2->GetWhitePoint();
       
       return wp1.IsSimilar(wp2, tolerance);
}
 
// Example 3: Chromatic adaptation
// When converting between color spaces with different white points,
// chromatic adaptation is needed
icmm::CVarColor AdaptColor(const icmm::CVarColor& color,
                          const icmm::IWhitePointProvider* sourceWP,
                          const icmm::IWhitePointProvider* destWP)
{
       icmm::CVarColor sourceWhite = sourceWP->GetWhitePoint();
       icmm::CVarColor destWhite = destWP->GetWhitePoint();
       
       // Apply chromatic adaptation transform (simplified)
       // Real implementation would use Bradford, von Kries, etc.
       // ...
       
       return color;  // Adapted color
}
 
// Example 4: Checking if adaptation is needed
bool NeedsAdaptation(const icmm::IWhitePointProvider* source,
                    const icmm::IWhitePointProvider* dest)
{
       return !SameWhitePoint(source, dest);
}

Applications

White points are used for:

• Color space conversion: Ensuring colors appear consistent
• Chromatic adaptation: Simulating how colors look under different lights
• Display calibration: Matching screen white to desired standard
• Print preparation: Converting from D65 (screen) to D50 (print)
• Color appearance modeling: Advanced perceptual color models

See also

icmm::IIlluminant, icmm::IColorSpecification, icmm::ITristimulusSpecification, icmm::CXyzToCieLabTransformation

Definition at line 105 of file IWhitePointProvider.h.

Member Function Documentation

GetWhitePoint()

virtual icmm::CVarColor icmm::IWhitePointProvider::GetWhitePoint ( ) const

pure virtual

Gets the white point as a color value.

Returns the white point typically as XYZ tristimulus values in a CVarColor. The white point defines what color should be considered as "white" or "neutral" in the color space.

Returns

CVarColor containing the white point, typically XYZ coordinates

Note

White point is usually normalized so Y component = 1.0

Common white points: D65 (X=0.95047, Y=1.0, Z=1.08883)

See also

IIlluminant::GetWhitePoint()

Implemented in icmm::CIlluminant.

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

• Acf/Include/icmm/IWhitePointProvider.h