LeastSignificantBit Class Reference

Inheritance diagram for LeastSignificantBit:

Collaboration diagram for LeastSignificantBit:

Public Member Functions
	LeastSignificantBit (const boost::filesystem::path &image_path)
void	Encode (const boost::filesystem::path &)
void	Decode ()
Public Member Functions inherited from Steganography
	Steganography (const boost::filesystem::path &image_path)

Private Member Functions
void	EncodeChunk (const int &start, std::vector< unsigned char >::iterator it, std::vector< unsigned char >::iterator en)
void	EncodeChunkLength (const int &start, const unsigned int &chunk_length)
void	DecodeChunk (const int start, std::vector< unsigned char >::iterator it, std::vector< unsigned char >::iterator en)
unsigned int	DecodeChunkLength (const int &start)

Private Attributes
int	image_capacity

Additional Inherited Members
Protected Member Functions inherited from Steganography
std::vector< unsigned char >	ReadPayload (const boost::filesystem::path &payload_path)
void	WritePayload (const boost::filesystem::path &payload_path, const std::vector< unsigned char > &payload)
template<class T >
void	SetBit (T *target, const int &bit, const int &value)
template<class T >
int	GetBit (const T &target, const int &bit)
Protected Attributes inherited from Steganography
boost::filesystem::path	image_path
cv::Mat	image

Constructor & Destructor Documentation

LeastSignificantBit()

LeastSignificantBit::LeastSignificantBit ( const boost::filesystem::path &  image_path )

inline

Default constructor for LeastSignificantBit class overrides the default constructor for the Steganography class.

Parameters

image_path

The path to the input carrier image.

Member Function Documentation

Decode()

void LeastSignificantBit::Decode ( )

virtual

Decode the payload from the steganographic image by reading from one or more least significant bits.

Implements Steganography.

DecodeChunk()

void LeastSignificantBit::DecodeChunk ( const int  start, std::vector< unsigned char >::iterator  it, std::vector< unsigned char >::iterator  en  )

private

Attempt to decode a chunk of information from the steganographic image.

Parameters

start	The bit index to start decoding at.
it	An iterator to a start position in the payload_bytes vector.
en	An iterator to an end position in the payload_bytes vector.

Exceptions

DecodeException

Thrown when decoding fails.

DecodeChunkLength()

unsigned int LeastSignificantBit::DecodeChunkLength ( const int &  start )

private

Attempt to decode the 32bit integer stating the length of the following chunk.

Parameters

start

The bit index to start decoding at.

Returns

The length of the following chunk.

Exceptions

DecodeException

Thrown when decoding fails.

Encode()

void LeastSignificantBit::Encode ( const boost::filesystem::path &  payload_path )

virtual

Encode the payload file into the carrier image by embedding into one or more least significant bits.

Parameters

payload_path

Path to the file we are encoding.

Exceptions

EncodeException

Thrown when encoding fails.

Implements Steganography.

EncodeChunk()

void LeastSignificantBit::EncodeChunk ( const int &  start, std::vector< unsigned char >::iterator  it, std::vector< unsigned char >::iterator  en  )

private

Encode a chunk of information into the carrier image.

Before encoding a chunk of information you "should" first encode its length using the EncodeChunkLength function.

Parameters

start	The bit index to start encoding at.
it	The position in the chunk of information to start encoding.
en	The position in the chunk of information to stop encoding.

EncodeChunkLength()

void LeastSignificantBit::EncodeChunkLength ( const int &  start, const unsigned int &  chunk_length  )

private

Encode a 32bit integer stating the length of the following chunk into the carrier image.

Parameters

start	The bit index to start encoding at.
chunk_length	The length of the next chunk in bytes.

Member Data Documentation

image_capacity

LeastSignificantBit::image_capacity

private

The total capacity of the carrier image in bits.

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

• include/least_significant_bit.hpp
• src/least_significant_bit.cpp