CMYK color model implementation for four-color printing. More...

#include <CCmykColorModel.h>

Inheritance diagram for icmm::CCmykColorModel:

Public Types
typedef CCmyColorModel	BaseClass

Public Types inherited from icmm::IColorModel
enum	ModelType { MT_HSI , MT_HSV , MT_HSL , MI_YIQ , MI_YUV , MI_YCBCR , MT_RGB , MT_COLORANTS , MT_LUV , MT_LAB , MT_LCH , MT_XYZ , MT_YXY , MI_SPECTRAL , MI_USER = 1024 }

enum	ModelClass { MC_DEVICE_DEPENDENT , MC_DEVICE_INDEPENDENT }

enum	ColorSpaceClass { CSC_ADDITIVE , CSC_SUBSTRACTIVE , CSC_PERCEPTUAL }

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

Public Types inherited from icmm::IColorantList
typedef QString	ColorantId

typedef QStringList	ColorantIds

Public Member Functions
virtual ColorantIds	GetColorantIds () const override
	Get the list of colorant-IDs.

virtual icmm::ColorantUsage	GetColorantUsage (const ColorantId &colorantId) const override
	Get type of the colorant with the given ID.

virtual std::unique_ptr< ISubstractiveColorModel >	CreateSubspaceModel (const QStringList &colorantIds) const override
	Create ColorModel of the subspace.

virtual istd::IChangeableUniquePtr	CloneMe (CompatibilityMode mode=CM_WITHOUT_REFS) const override
	Make a copy of this object.

Public Member Functions inherited from icmm::CSubstractiveColorModelBase
	CSubstractiveColorModelBase ()

const icmm::CTristimulusSpecification &	GetPreviewSpec () const

void	SetPreviewSpec (const ITristimulusSpecification &previewSpec)

void	SetColorantPreview (const ColorantId &colorantId, const icmm::CLab &preview)

virtual ModelType	GetModelType () const override
	Gets the type of the color model.

virtual ModelClass	GetModelClass () const override
	Gets the classification of the color model.

virtual ColorSpaceClass	GetColorSpaceClass () const override
	Gets the classification of the color space defined by this model.

virtual int	GetColorSpaceDimensionality () const override
	Gets the dimensionality (number of components) of the color space.

virtual const imath::IUnitInfo *	GetColorSpaceComponentInfo (int componentIndex) const override
	Gets mathematical unit information for a color model component.

virtual QString	GetColorSpaceComponentName (int componentIndex) const override
	Gets the human-readable name of a color model component.

virtual const icmm::IColorTransformation *	CreateColorTranformation (const IColorModel &otherColorModel, const QByteArray &transformationId=QByteArray()) const override
	Creates a color transformation for conversion to another color model.

virtual bool	GetColorantVisualInfo (const ColorantId &colorantId, icmm::ICieLabColor &preview) const override
	Get visual information/preview for the given colorant.

virtual int	GetSupportedOperations () const override
	Get set of flags for supported operations.

virtual bool	CopyFrom (const istd::IChangeable &object, CompatibilityMode mode=CM_WITHOUT_REFS) override
	Copy this object from another one.

Public Member Functions inherited from icmm::IColorModel
virtual IColorSpecification::ConstColorSpecPtr	GetSpecification () const
	Gets the color specification for this model, if available.

Public Member Functions inherited from istd::IChangeable
virtual bool	IsEqual (const IChangeable &object) const
	Compare this object with another 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 ()

Static Public Member Functions
static ColorantId	GetBlack ()
	Gets the colorant ID for the black (K) component.

Static Public Member Functions inherited from icmm::CCmyColorModel
static ColorantId	GetCyan ()

static ColorantId	GetMagenta ()

static ColorantId	GetYellow ()

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.

Additional Inherited Members
Protected Types inherited from icmm::CSubstractiveColorModelBase
typedef QMap< ColorantId, icmm::CLab >	ColorantPreviewMap
	Mapping between a colorant and corresponding Lab value for its solid value.

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.

Protected Attributes inherited from icmm::CSubstractiveColorModelBase
icmm::CTristimulusSpecification	m_previewSpec
	Tristimulus specification used for all colorants in the color model.

ColorantPreviewMap	m_colorantPreviewMap

Detailed Description

CMYK color model implementation for four-color printing.

Purpose

CCmykColorModel extends CCmyColorModel to represent the full CMYK (Cyan, Magenta, Yellow, Black) color model used in printing. The addition of black (K) ink provides better shadow detail, reduced ink consumption, and improved print quality compared to CMY alone.

Design

CCmykColorModel provides:

Four colorants: Cyan, Magenta, Yellow, Black (K)
Colorant management: Query and manipulate individual ink channels
Subspace creation: Create models with subset of colorants
Printing optimization: Black generation and ink limiting

Usage Examples

// Example 1: Basic CMYK model usage
icmm::CCmykColorModel cmykModel;
 
// Query model properties
IColorModel::ModelType type = cmykModel.GetModelType();  // MT_CMYK
int dims = cmykModel.GetColorSpaceDimensionality();      // 4
 
// Get colorant IDs
icmm::ColorantIds colorants = cmykModel.GetColorantIds();
// Returns list: ["Cyan", "Magenta", "Yellow", "Black"]
 
// Example 2: Querying colorant information
void InspectCmykColorants(const icmm::CCmykColorModel& model)
{
       icmm::ColorantIds ids = model.GetColorantIds();
       
       for (const icmm::ColorantId& id : ids) {
              icmm::ColorantUsage usage = model.GetColorantUsage(id);
              
              qDebug() << "Colorant:" << id;
              qDebug() << "Usage:" << (int)usage;
              
              // Usage indicates if colorant is process, spot, etc.
       }
}
 
// Example 3: Getting black colorant specifically
icmm::ColorantId GetBlackColorant()
{
       // Static method to get black colorant ID
       return icmm::CCmykColorModel::GetBlack();
}
 
// Example 4: Creating subspace models
icmm::ISubstractiveColorModel* CreateCmyOnly()
{
       icmm::CCmykColorModel cmykModel;
       
       // Create subspace with only CMY (no black)
       QStringList cmyColorants;
       cmyColorants << "Cyan" << "Magenta" << "Yellow";
       
       std::unique_ptr<icmm::ISubstractiveColorModel> cmyModel = 
              cmykModel.CreateSubspaceModel(cmyColorants);
       
       return cmyModel.release();
}
 
// Example 5: Converting RGB to CMYK
void ConvertRgbToCmyk(const icmm::CVarColor& rgb)
{
       icmm::CRgbColorModel rgbModel;
       icmm::CCmykColorModel cmykModel;
       
       // Create transformation
       const icmm::IColorTransformation* transform = 
              rgbModel.CreateColorTranformation(cmykModel);
       
       if (transform) {
              icmm::CVarColor cmyk;
              if (transform->Calculate(rgb, cmyk)) {
                     double c = cmyk.GetElement(0);  // Cyan
                     double m = cmyk.GetElement(1);  // Magenta
                     double y = cmyk.GetElement(2);  // Yellow
                     double k = cmyk.GetElement(3);  // Black
                     
                     qDebug() << "CMYK:" << c << m << y << k;
              }
              delete transform;
       }
}
 
// Example 6: Checking ink coverage
double CalculateInkCoverage(const icmm::CVarColor& cmyk)
{
       // Total Area Coverage (TAC) - sum of all ink percentages
       double tac = 0.0;
       
       for (int i = 0; i < cmyk.GetElementsCount(); ++i) {
              tac += cmyk.GetElement(i);
       }
       
       // TAC typically should not exceed 300-400% depending on press
       return tac * 100.0;  // Convert to percentage
}
 
// Example 7: Working with spot colors
void AddSpotColorant(icmm::CCmykColorModel& model)
{
       // CMYK model can be extended with spot colors
       // for special printing applications (metallic, varnish, etc.)
       
       // Get current colorants
       icmm::ColorantIds ids = model.GetColorantIds();
       
       // Could add additional colorants for extended gamut printing
       // (e.g., Orange, Green for 6-color CMYK+OG)
}
 
// Example 8: Comparing CMYK models
bool ModelsSupportSameColorants(const icmm::CCmykColorModel& model1,
                               const icmm::CCmykColorModel& model2)
{
       icmm::ColorantIds ids1 = model1.GetColorantIds();
       icmm::ColorantIds ids2 = model2.GetColorantIds();
       
       if (ids1.size() != ids2.size()) {
              return false;
       }
       
       // Check if all colorants match
       for (const auto& id : ids1) {
              if (!ids2.contains(id)) {
                     return false;
              }
       }
       
       return true;
}

Black Generation

The "K" component provides several benefits:

Better shadows: Pure black ink creates deeper blacks than CMY mix
Reduced ink: Replacing CMY with K saves expensive color inks
Faster drying: Less total ink on paper
Registration: Easier to align (K carries most shadow detail)

Common strategies:

GCR (Gray Component Replacement): Replace CMY gray with K
UCR (Under Color Removal): Remove CMY under blacks
Maximum K: Use K for all neutral tones
Minimum K: Use K only in deep shadows

Applications

Commercial printing: Offset, digital, screen printing
Desktop publishing: Print preparation and proofing
Color separation: Converting RGB artwork to print
Ink optimization: Reducing costs and improving quality
Spot color: Extended gamut and special inks

Best Practices

Monitor total ink coverage (TAC) - typically max 300-400%
Use appropriate black generation for content type
Consider paper type (coated vs uncoated affects ink limits)
Proof on actual print device when possible
Use ICC profiles for accurate RGB->CMYK conversion
Check registration and trapping requirements

See also: icmm::CCmyColorModel, icmm::ISubstractiveColorModel, icmm::CCmyk, icmm::CRgbToCmykTransformation, icmm::IColorantList

Definition at line 185 of file CCmykColorModel.h.

Member Typedef Documentation

◆ BaseClass

typedef CCmyColorModel icmm::CCmykColorModel::BaseClass

Definition at line 188 of file CCmykColorModel.h.

Member Function Documentation

◆ CloneMe()

virtual istd::IChangeableUniquePtr icmm::CCmykColorModel::CloneMe ( CompatibilityMode mode = CM_WITHOUT_REFS ) const

overridevirtual

Make a copy of this object.

Returns: new instance or NULL, if this operation is not supported.

Reimplemented from icmm::CCmyColorModel.

◆ CreateSubspaceModel()

virtual std::unique_ptr< ISubstractiveColorModel > icmm::CCmykColorModel::CreateSubspaceModel ( const QStringList & colorantIds ) const

overridevirtual

Create ColorModel of the subspace.

Reimplemented from icmm::CCmyColorModel.

◆ GetBlack()

static ColorantId icmm::CCmykColorModel::GetBlack ( )

static

Gets the colorant ID for the black (K) component.

Static method to retrieve the standard identifier for the black colorant in CMYK printing. Useful for querying or manipulating the black channel specifically.

Returns: ColorantId for black component

See also: GetColorantIds()

◆ GetColorantIds()

virtual ColorantIds icmm::CCmykColorModel::GetColorantIds ( ) const

overridevirtual

Get the list of colorant-IDs.

Reimplemented from icmm::CCmyColorModel.

◆ GetColorantUsage()

virtual icmm::ColorantUsage icmm::CCmykColorModel::GetColorantUsage ( const ColorantId & colorantId ) const

overridevirtual

Get type of the colorant with the given ID.

Reimplemented from icmm::CCmyColorModel.

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

Acf/Include/icmm/CCmykColorModel.h

Public Types

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Purpose

Design

Usage Examples

Black Generation

Applications

Best Practices

Member Typedef Documentation

◆ BaseClass

Member Function Documentation

◆ CloneMe()

◆ CreateSubspaceModel()

◆ GetBlack()

◆ GetColorantIds()

◆ GetColorantUsage()