steghide 0.5.1
Public Member Functions | Protected Attributes | Private Attributes | List of all members
SampleValue Class Referenceabstract

the value of a sample in a CvrStgFile More...

#include <SampleValue.h>

Inheritance diagram for SampleValue:
AudioSampleValue< Type, ValueType > BmpSampleValue DummySampleValue JpegSampleValue WavPCMSampleValue BmpPaletteSampleValue BmpRGBSampleValue

Public Member Functions

 SampleValue (void)
 
virtual ~SampleValue (void)
 
virtual SampleValuegetNearestTargetSampleValue (EmbValue t) const =0
 
virtual UWORD32 calcDistance (const SampleValue *s) const =0
 
virtual std::string getName (void) const =0
 
virtual bool isNeighbour (const SampleValue *s) const
 
EmbValue getEmbeddedValue (void) const
 
UWORD32 getKey (void) const
 
bool operator== (const SampleValue &sv) const
 
bool operator!= (const SampleValue &sv) const
 
bool operator< (const SampleValue &sv) const
 
UWORD32 getNumEdges (EmbValue t) const
 
void setNumEdges (EmbValue t, UWORD32 ne)
 
void incNumEdges (EmbValue t)
 
void decNumEdges (EmbValue t)
 
void setLabel (unsigned long l)
 
unsigned long getLabel (void) const
 
void print (unsigned short spc=0) const
 

Protected Attributes

EmbValue EValue
 the bit that is embedded in this sample value - must be set in constructor of derived class
 
UWORD32 Key
 the key of this sample value - must be different for two different sample values - must be set in constructor of derived class
 

Private Attributes

unsigned long Label
 
UWORD32NumEdges
 

Detailed Description

This is the abstract base class for all AuSampleValue, BmpSampleValue, etc. classes

For two sample values s1 and s2:

s1->calcDistance(s2) == s2->calcDistance(s1) is always true.

s1->isNeighbour(s2) == s2->isNeighbour(s1) is always true.

s1 and s2 are called opposite if s1->getBit() != s2->getBit()

s1 and s2 are called neighbours if s1->isNeighbour(s2) is true

s1->getKey() == s2->getKey() iff s1 == s2

s1 == s2 implies s1->getDistance(s2) == 0 BUT: s1->getDistance(s2) == 0 does not imply s1 == s2 example: 8-bit bmp palette image - same color value for two different indices

s1 == s2 implies s1->getBit() == s2->getBit()

s1->getDistance(s2) == 0 implies s1->getBit() == s2->getBit()

NOTE: SampleValue and all derived classes rely on the Globals object pointed to by the Globs pointer. This means that it must be set correctly before using any method of a SampleValue (or derived) object.

Constructor & Destructor Documentation

◆ SampleValue()

SampleValue::SampleValue ( void  )

◆ ~SampleValue()

SampleValue::~SampleValue ( void  )
virtual

Member Function Documentation

◆ calcDistance()

virtual UWORD32 SampleValue::calcDistance ( const SampleValue s) const
pure virtual

calculate the distance between the sample value s and this sample value

Parameters
sa sample value of the same type as this
Returns
the distance

Implemented in AudioSampleValue< Type, ValueType >, BmpRGBSampleValue, BmpSampleValue, JpegSampleValue, WavPCMSampleValue, and DummySampleValue.

◆ decNumEdges()

void SampleValue::decNumEdges ( EmbValue  t)

◆ getEmbeddedValue()

EmbValue SampleValue::getEmbeddedValue ( void  ) const
inline

get the value that is embedded in this sample value (must be >=0 and <EmbValueModulus)

Returns
the embedded value

◆ getKey()

UWORD32 SampleValue::getKey ( void  ) const
inline

get the key for this sample

Returns
a key which must be different for two different samples values.

◆ getLabel()

unsigned long SampleValue::getLabel ( void  ) const
inline

◆ getName()

virtual std::string SampleValue::getName ( void  ) const
pure virtual

return a short name uniquely identifying this sample value

Implemented in AudioSampleValue< Type, ValueType >, BmpPaletteSampleValue, BmpRGBSampleValue, JpegSampleValue, WavPCMSampleValue, and DummySampleValue.

◆ getNearestTargetSampleValue()

virtual SampleValue * SampleValue::getNearestTargetSampleValue ( EmbValue  t) const
pure virtual

get the nearest (with the least distance to this sample value) sample value whose embedded value equals the specified target

Parameters
tthe target embedded value

If two or more target sample values have equal distance each of them should be returned with equal probability.

The returned SampleValue object should be deleted by the callser.

Implemented in AudioSampleValue< Type, ValueType >, BmpPaletteSampleValue, BmpRGBSampleValue, JpegSampleValue, WavPCMSampleValue, and DummySampleValue.

◆ getNumEdges()

UWORD32 SampleValue::getNumEdges ( EmbValue  t) const
inline

◆ incNumEdges()

void SampleValue::incNumEdges ( EmbValue  t)

◆ isNeighbour()

bool SampleValue::isNeighbour ( const SampleValue s) const
virtual

is the sample value s a neighbour of this sample value ?

Returns
true iff this and s are neighbours

This is implemented as (calcDistance() <= Radius) but may be overridden by derived classes.

Reimplemented in DummySampleValue.

◆ operator!=()

bool SampleValue::operator!= ( const SampleValue sv) const
inline

◆ operator<()

bool SampleValue::operator< ( const SampleValue sv) const
inline

◆ operator==()

bool SampleValue::operator== ( const SampleValue sv) const
inline

two sample values are equal iff their keys are equal

◆ print()

void SampleValue::print ( unsigned short  spc = 0) const

◆ setLabel()

void SampleValue::setLabel ( unsigned long  l)
inline

◆ setNumEdges()

void SampleValue::setNumEdges ( EmbValue  t,
UWORD32  ne 
)
inline

Member Data Documentation

◆ EValue

EmbValue SampleValue::EValue
protected

◆ Key

UWORD32 SampleValue::Key
protected

◆ Label

unsigned long SampleValue::Label
private

◆ NumEdges

UWORD32* SampleValue::NumEdges
private

NumEdges[t] contains the number of edges that are added to a vertex if this sample value with corresponding target value t is added to the vertex


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