SampleValue Class Reference

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 List of all members.

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 ( void   ) 

SampleValue::~SampleValue ( void   )  [virtual]


Member Function Documentation

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:
t the 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.

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

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

Parameters:
s a sample value of the same type as this
Returns:
the distance

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

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.

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.

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

UWORD32 SampleValue::getKey ( void   )  const [inline]

get the key for this sample

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

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

two sample values are equal iff their keys are equal

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

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

UWORD32 SampleValue::getNumEdges ( EmbValue  t  )  const [inline]

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

void SampleValue::incNumEdges ( EmbValue  t  ) 

void SampleValue::decNumEdges ( EmbValue  t  ) 

void SampleValue::setLabel ( unsigned long  l  )  [inline]

unsigned long SampleValue::getLabel ( void   )  const [inline]

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


Member Data Documentation

EmbValue SampleValue::EValue [protected]

UWORD32 SampleValue::Key [protected]

unsigned long SampleValue::Label [private]

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:
Generated on Fri Feb 2 09:19:56 2007 for steghide by  doxygen 1.5.1