Wavelet channel class. More...

#include <Subband.h>

Public Member Functions
	CSubband ()
	~CSubband ()
bool	AllocMemory ()
void	FreeMemory ()
void	ExtractTile (CEncoder &encoder, bool tile=false, UINT32 tileX=0, UINT32 tileY=0) THROW_
void	PlaceTile (CDecoder &decoder, int quantParam, bool tile=false, UINT32 tileX=0, UINT32 tileY=0) THROW_
void	Quantize (int quantParam)
void	Dequantize (int quantParam)
void	SetData (UINT32 pos, DataT v)
DataT *	GetBuffer ()
DataT	GetData (UINT32 pos) const
int	GetLevel () const
int	GetHeight () const
int	GetWidth () const
Orientation	GetOrientation () const
UINT32	BufferWidth () const
void	IncBuffRow (UINT32 pos)
Private Member Functions
void	Initialize (UINT32 width, UINT32 height, int level, Orientation orient)
void	WriteBuffer (DataT val)
void	SetBuffer (DataT *b)
DataT	ReadBuffer ()
UINT32	GetBuffPos () const
void	TilePosition (UINT32 tileX, UINT32 tileY, UINT32 &left, UINT32 &top, UINT32 &w, UINT32 &h) const
void	SetROI (CROIs *roi)
void	InitBuffPos (UINT32 left=0, UINT32 top=0)
Private Attributes
UINT32	m_width
UINT32	m_height
UINT32	m_size
int	m_level
Orientation	m_orientation
UINT32	m_dataPos
DataT *	m_data
CROIs *	m_ROIs
UINT32	m_dataWidth
Friends
class	CWaveletTransform

Detailed Description

Wavelet channel class.

PGF wavelet channel subband class.

Author:: C. Stamm, R. Spuler

Constructor & Destructor Documentation

CSubband::CSubband ( )

Standard constructor.

Definition at line 35 of file Subband.cpp.

                   : m_size(0), m_data(0)
#ifdef __PGFROISUPPORT__
, m_ROIs(0), m_dataWidth(0) 
#endif
{
}

CSubband::~CSubband ( )

Destructor.

Definition at line 44 of file Subband.cpp.

                    {
        FreeMemory();
}

Member Function Documentation

bool CSubband::AllocMemory ( )

Allocate a memory buffer to store all wavelet coefficients of this subband.

Returns:: True if the allocation did work without any problems

Definition at line 68 of file Subband.cpp.

                           {
        UINT32 oldSize = m_size;

#ifdef __PGFROISUPPORT__
        if (m_ROIs) {
                // reset dataWidth and size
                const PGFRect& roi = m_ROIs->GetROI(m_level);
                m_dataWidth = __min(m_width, roi.right) - roi.left;
                ASSERT(m_dataWidth > 0);
                m_size = m_dataWidth*(__min(m_height, roi.bottom) - roi.top);
        }
#endif
        ASSERT(m_size > 0);

        if (m_data) {
                if (oldSize >= m_size) {
                        return true;
                } else {
                        delete[] m_data;
                        m_data = new(std::nothrow) DataT[m_size];
                        return (m_data != 0);
                }
        } else {
                m_data = new(std::nothrow) DataT[m_size];
                return (m_data != 0);
        }
}

UINT32 CSubband::BufferWidth ( ) const [inline]

Return data buffer line width.

Definition at line 140 of file Subband.h.

{ return m_dataWidth; }

void CSubband::Dequantize ( int quantParam )

Perform subband dequantization with given quantization parameter. A scalar quantization (with dead-zone) is used. A large quantization value results in strong quantization and therefore in big quality loss.

Parameters:

quantParam A quantization parameter (larger or equal to 0)

Definition at line 151 of file Subband.cpp.

                                        {
        if (m_orientation == LL) {
                quantParam -= m_level + 1;
        } else if (m_orientation == HH) {
                quantParam -= m_level - 1;
        } else {
                quantParam -= m_level;
        }
        if (quantParam > 0) {
                for (UINT32 i=0; i < m_size; i++) {
                        m_data[i] <<= quantParam;
                }
        }
}

void CSubband::ExtractTile	(	CEncoder &	encoder,
		bool	tile = `false`,
		UINT32	tileX = `0`,
		UINT32	tileY = `0`
	)

Extracts a rectangular subregion of this subband. Write wavelet coefficients into buffer. It might throw an IOException.

Parameters:

encoder	An encoder instance
quant	A quantization value (linear scalar quantization)
tile	True if just a rectangular region is extracted, false if the entire subband is extracted.
tileX	Tile index in x-direction
tileY	Tile index in y-direction

Extracts a rectangular subregion of this subband. Write wavelet coefficients into buffer. It might throw an IOException.

Parameters:

encoder	An encoder instance
tile	True if just a rectangular region is extracted, false if the entire subband is extracted.
tileX	Tile index in x-direction
tileY	Tile index in y-direction

Definition at line 174 of file Subband.cpp.

                                                                                                {
#ifdef __PGFROISUPPORT__
        if (tile) {
                // compute tile position and size
                UINT32 xPos, yPos, w, h;
                TilePosition(tileX, tileY, xPos, yPos, w, h);

                // write values into buffer using partitiong scheme
                encoder.Partition(this, w, h, xPos + yPos*m_width, m_width);
        } else 
#endif
        {
                // write values into buffer using partitiong scheme
                encoder.Partition(this, m_width, m_height, 0, m_width);
        }
}

void CSubband::FreeMemory ( )

Delete the memory buffer of this subband.

Definition at line 98 of file Subband.cpp.

                          {
        if (m_data) {
                delete[] m_data; m_data = 0;
        }
}

DataT* CSubband::GetBuffer ( ) [inline]

Get a pointer to an array of all wavelet coefficients of this subband.

Returns:: Pointer to array of wavelet coefficients

Definition at line 107 of file Subband.h.

{ return m_data; }

UINT32 CSubband::GetBuffPos ( ) const [inline, private]

Definition at line 155 of file Subband.h.

{ return m_dataPos; }

DataT CSubband::GetData ( UINT32 pos ) const [inline]

Return wavelet coefficient at given position.

Parameters:

pos	A subband position (>= 0)

Returns:: Wavelet coefficient

Definition at line 113 of file Subband.h.

{ ASSERT(pos < m_size); return m_data[pos]; }

int CSubband::GetHeight ( ) const [inline]

Return height of this subband.

Returns:: Height of this subband (in pixels)

Definition at line 123 of file Subband.h.

{ return m_height; }

int CSubband::GetLevel ( ) const [inline]

Return level of this subband.

Returns:: Level of this subband

Definition at line 118 of file Subband.h.

{ return m_level; }

Orientation CSubband::GetOrientation ( ) const [inline]

Return orientation of this subband. LL LH HL HH

Returns:: Orientation of this subband (LL, HL, LH, HH)

Definition at line 135 of file Subband.h.

{ return m_orientation; }

int CSubband::GetWidth ( ) const [inline]

Return width of this subband.

Returns:: Width of this subband (in pixels)

Definition at line 128 of file Subband.h.

{ return m_width; }

void CSubband::IncBuffRow ( UINT32 pos ) [inline]

Set data buffer position to given position + one row.

Parameters:

pos	Given position

Definition at line 145 of file Subband.h.

{ m_dataPos = pos + m_dataWidth; }

void CSubband::InitBuffPos	(	UINT32	left = `0`,
		UINT32	top = `0`
	)		`[inline, private]`

Definition at line 161 of file Subband.h.

{ m_dataPos = top*m_dataWidth + left; ASSERT(m_dataPos < m_size); }

void CSubband::Initialize	(	UINT32	width,
		UINT32	height,
		int	level,
		Orientation	orient
	)		`[private]`

Definition at line 50 of file Subband.cpp.

                                                                                    {
        m_width = width;
        m_height = height;
        m_size = m_width*m_height;
        m_level = level;
        m_orientation = orient;
        m_data = 0;
        m_dataPos = 0;
#ifdef __PGFROISUPPORT__
        m_ROIs = 0;
        m_dataWidth = width;
#endif
}

void CSubband::PlaceTile	(	CDecoder &	decoder,
		int	quantParam,
		bool	tile = `false`,
		UINT32	tileX = `0`,
		UINT32	tileY = `0`
	)

Decoding and dequantization of this subband. It might throw an IOException.

Parameters:

decoder	A decoder instance
quantParam	Dequantization value
tile	True if just a rectangular region is placed, false if the entire subband is placed.
tileX	Tile index in x-direction
tileY	Tile index in y-direction

Definition at line 199 of file Subband.cpp.

                                                                                                              {
        // allocate memory
        if (!AllocMemory()) ReturnWithError(InsufficientMemory);

        // correct quantParam with normalization factor
        if (m_orientation == LL) {
                quantParam -= m_level + 1;
        } else if (m_orientation == HH) {
                quantParam -= m_level - 1;
        } else {
                quantParam -= m_level;
        }
        if (quantParam < 0) quantParam = 0;

#ifdef __PGFROISUPPORT__
        if (tile) {
                // compute tile position and size
                const PGFRect& roi = m_ROIs->GetROI(m_level);
                UINT32 xPos, yPos, w, h;
                TilePosition(tileX, tileY, xPos, yPos, w, h);

                // read values into buffer using partitiong scheme
                decoder.Partition(this, quantParam, w, h, (xPos - roi.left) + (yPos - roi.top)*m_dataWidth, m_dataWidth);
        } else 
#endif
        {
                // read values into buffer using partitiong scheme
                decoder.Partition(this, quantParam, m_width, m_height, 0, m_width);
        }
}

void CSubband::Quantize ( int quantParam )

Perform subband quantization with given quantization parameter. A scalar quantization (with dead-zone) is used. A large quantization value results in strong quantization and therefore in big quality loss.

Parameters:

quantParam A quantization parameter (larger or equal to 0)

Definition at line 109 of file Subband.cpp.

                                      {
        if (m_orientation == LL) {
                quantParam -= (m_level + 1);
                // uniform rounding quantization
                if (quantParam > 0) {
                        quantParam--;
                        for (UINT32 i=0; i < m_size; i++) {
                                if (m_data[i] < 0) {
                                        m_data[i] = -(((-m_data[i] >> quantParam) + 1) >> 1);
                                } else {
                                        m_data[i] = ((m_data[i] >> quantParam) + 1) >> 1;
                                }
                        }
                }
        } else {
                if (m_orientation == HH) {
                        quantParam -= (m_level - 1);
                } else {
                        quantParam -= m_level;
                }
                // uniform deadzone quantization
                if (quantParam > 0) {
                        int threshold = ((1 << quantParam) * 7)/5;      // good value
                        quantParam--;
                        for (UINT32 i=0; i < m_size; i++) {
                                if (m_data[i] < -threshold) {
                                        m_data[i] = -(((-m_data[i] >> quantParam) + 1) >> 1);
                                } else if (m_data[i] > threshold) {
                                        m_data[i] = ((m_data[i] >> quantParam) + 1) >> 1;
                                } else {
                                        m_data[i] = 0;
                                }
                        }
                }
        }
}

DataT CSubband::ReadBuffer ( ) [inline, private]

Definition at line 153 of file Subband.h.

{ ASSERT(m_dataPos < m_size); return m_data[m_dataPos++]; }

void CSubband::SetBuffer ( DataT * b ) [inline, private]

Definition at line 152 of file Subband.h.

{ ASSERT(b); m_data = b; }

void CSubband::SetData	(	UINT32	pos,
		DataT	v
	)		`[inline]`

Store wavelet coefficient in subband at given position.

Parameters:

pos	A subband position (>= 0)
v	A wavelet coefficient

Definition at line 102 of file Subband.h.

{ ASSERT(pos < m_size); m_data[pos] = v; }

void CSubband::SetROI ( CROIs * roi ) [inline, private]

Definition at line 160 of file Subband.h.

{ ASSERT(roi); m_ROIs = roi; }

void CSubband::TilePosition	(	UINT32	tileX,
		UINT32	tileY,
		UINT32 &	xPos,
		UINT32 &	yPos,
		UINT32 &	w,
		UINT32 &	h
	)		const `[private]`

Compute tile position and size.

Parameters:

tileX	Tile index in x-direction
tileY	Tile index in y-direction
xPos	[out] Offset to left
yPos	[out] Offset to top
w	[out] Tile width
h	[out] Tile height

Definition at line 241 of file Subband.cpp.

                                                                                                              {
        // example
        // band = HH, w = 30, ldTiles = 2 -> 4 tiles in a row/column
        // --> tile widths
        // 8 7 8 7
        // 
        // tile partitioning scheme
        // 0 1 2 3
        // 4 5 6 7
        // 8 9 A B
        // C D E F

        UINT32 nTiles = m_ROIs->GetNofTiles(m_level);
        ASSERT(tileX < nTiles); ASSERT(tileY < nTiles);
        UINT32 m;
        UINT32 left = 0, right = nTiles;
        UINT32 top = 0, bottom = nTiles;

        xPos = 0;
        yPos = 0;
        w = m_width;
        h = m_height;

        while (nTiles > 1) {
                // compute xPos and w with binary search
                m = (left + right) >> 1;
                if (tileX >= m) {
                        xPos += (w + 1) >> 1;
                        w >>= 1;
                        left = m;
                } else {
                        w = (w + 1) >> 1;
                        right = m;
                }
                // compute yPos and h with binary search
                m = (top + bottom) >> 1;
                if (tileY >= m) {
                        yPos += (h + 1) >> 1;
                        h >>= 1;
                        top = m;
                } else {
                        h = (h + 1) >> 1;
                        bottom = m;
                }
                nTiles >>= 1;
        }
        ASSERT(xPos < m_width && (xPos + w <= m_width));
        ASSERT(yPos < m_height && (yPos + h <= m_height));
}

void CSubband::WriteBuffer ( DataT val ) [inline, private]

Definition at line 151 of file Subband.h.

{ ASSERT(m_dataPos < m_size); m_data[m_dataPos++] = val; }

Friends And Related Function Documentation

friend class CWaveletTransform [friend]

Definition at line 43 of file Subband.h.

Member Data Documentation

DataT* CSubband::m_data [private]

Definition at line 182 of file Subband.h.

UINT32 CSubband::m_dataPos [private]

Definition at line 181 of file Subband.h.

UINT32 CSubband::m_dataWidth [private]

Definition at line 186 of file Subband.h.

UINT32 CSubband::m_height [private]

Definition at line 177 of file Subband.h.

int CSubband::m_level [private]

Definition at line 179 of file Subband.h.

Orientation CSubband::m_orientation [private]

Definition at line 180 of file Subband.h.

CROIs* CSubband::m_ROIs [private]

Definition at line 185 of file Subband.h.

UINT32 CSubband::m_size [private]

Definition at line 178 of file Subband.h.

UINT32 CSubband::m_width [private]

Definition at line 176 of file Subband.h.

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

Public Member Functions

Private Member Functions

Private Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation

Member Data Documentation