jj2000.j2k.image.invcomptransf

Class InvCompTransf

java.lang.Object

jj2000.j2k.image.ImgDataAdapter

jj2000.j2k.image.invcomptransf.InvCompTransf

All Implemented Interfaces:

BlkImgDataSrc, ImgData

public class InvCompTransf
extends ImgDataAdapter
implements BlkImgDataSrc

This class apply inverse component transformations to the tiles depending on specification read from the codestream header. These transformations can be used to improve compression efficiency but are not related to colour transforms used to map colour values for display purposes. JPEG 2000 part I defines 2 component transformations: RCT (Reversible Component Transformation) and ICT (Irreversible Component Transformation).

See Also:

ModuleSpec

Field Summary

Fields

Modifier and Type	Field and Description
private DataBlk	block0 Block used to request component 0
private DataBlk	block1 Block used to request component 1
private DataBlk	block2 Block used to request component 2
private CompTransfSpec	cts The component transformations specifications
private DataBlkInt	dbi Data block used only to store coordinates and progressiveness of the buffered blocks
static int	INV_ICT Identifier for the Inverse Irreversible Component Transformation (INV_ICT).
static int	INV_RCT Identifier for the Inverse Reversible Component Transformation (INV_RCT).
private boolean	noCompTransf Flag indicating whether the decoder should skip the component transform
static int	NONE Identifier for no component transformation.
static char	OPT_PREFIX The prefix for inverse component transformation options: 'M'
private int[][]	outdata Buffer for each component of output data
private static String[][]	pinfo The list of parameters that is accepted by the inverse component transformation module.
private BlkImgDataSrc	src The source of image data
private int	transfType The type of the current component transformation JPEG 2000 part I only support NONE, FORW_RCT and FORW_ICT types
private int[]	utdepth The bit-depths of un-transformed components
private SynWTFilterSpec	wfs The wavelet filter specifications

Fields inherited from class jj2000.j2k.image.ImgDataAdapter

imgdatasrc, tIdx

Constructor Summary

Constructors

Constructor and Description
InvCompTransf(BlkImgDataSrc imgSrc, DecoderSpecs decSpec, int[] utdepth) Constructs a new ForwCompTransf object that operates on the specified source of image data.

Method Summary

Methods

Modifier and Type	Method and Description
static int[]	calcMixedBitDepths(int[] utdepth, int ttype, int[] tdepth) Calculates the bitdepths of the transformed components, given the bitdepth of the un-transformed components and the component tranformation type.
DataBlk	getCompData(DataBlk blk, int c) Apply inverse component transformation associated with the current tile.
int	getFixedPoint(int c) Returns the position of the fixed point in the specified component.
DataBlk	getInternCompData(DataBlk blk, int c) Apply the inverse component transformation associated with the current tile.
int	getNomRangeBits(int c) Returns the number of bits, referred to as the "range bits", corresponding to the nominal range of the data in the specified component.
static String[][]	getParameterInfo() Returns the parameters that are used in this class and implementing classes.
private DataBlk	invICT(DataBlk blk, int c) Apply inverse irreversible component transformation to obtain requested component from specified block of data.
private DataBlk	invRCT(DataBlk blk, int c) Apply inverse component transformation to obtain requested component from specified block of data.
boolean	isReversible() Returns true if this transform is reversible in current tile.
void	nextTile() Advances to the next tile, in standard scan-line order (by rows then columns).
void	setTile(int x, int y) Changes the current tile, given the new indexes.
String	toString() Returns a string with a descriptive text of which inverse component transformation is used.

Methods inherited from class jj2000.j2k.image.ImgDataAdapter

getCompImgHeight, getCompImgWidth, getCompSubsX, getCompSubsY, getCompULX, getCompULY, getImgHeight, getImgULX, getImgULY, getImgWidth, getNomTileHeight, getNomTileWidth, getNumComps, getNumTiles, getNumTiles, getTile, getTileCompHeight, getTileCompWidth, getTileHeight, getTileIdx, getTilePartULX, getTilePartULY, getTileWidth

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface jj2000.j2k.image.ImgData

getCompImgHeight, getCompImgWidth, getCompSubsX, getCompSubsY, getCompULX, getCompULY, getImgHeight, getImgULX, getImgULY, getImgWidth, getNomTileHeight, getNomTileWidth, getNumComps, getNumTiles, getNumTiles, getTile, getTileCompHeight, getTileCompWidth, getTileHeight, getTileIdx, getTilePartULX, getTilePartULY, getTileWidth

Field Detail

NONE

public static final int NONE

Identifier for no component transformation. Value is 0.

See Also:

Constant Field Values

OPT_PREFIX

public static final char OPT_PREFIX

The prefix for inverse component transformation options: 'M'

See Also:

Constant Field Values

pinfo

private static final String[][] pinfo

The list of parameters that is accepted by the inverse component transformation module. They start with 'M'.

INV_RCT

public static final int INV_RCT

Identifier for the Inverse Reversible Component Transformation (INV_RCT). Value is 1.

See Also:

Constant Field Values

INV_ICT

public static final int INV_ICT

Identifier for the Inverse Irreversible Component Transformation (INV_ICT). Value is 2

See Also:

Constant Field Values

src

private BlkImgDataSrc src

The source of image data

cts

private CompTransfSpec cts

The component transformations specifications

wfs

private SynWTFilterSpec wfs

The wavelet filter specifications

transfType

private int transfType

The type of the current component transformation JPEG 2000 part I only support NONE, FORW_RCT and FORW_ICT types

outdata

private int[][] outdata

Buffer for each component of output data

block0

private DataBlk block0

Block used to request component 0

block1

private DataBlk block1

Block used to request component 1

block2

private DataBlk block2

Block used to request component 2

dbi

private DataBlkInt dbi

Data block used only to store coordinates and progressiveness of the buffered blocks

utdepth

private int[] utdepth

The bit-depths of un-transformed components

noCompTransf

private boolean noCompTransf

Flag indicating whether the decoder should skip the component transform

Constructor Detail

InvCompTransf

public InvCompTransf(BlkImgDataSrc imgSrc,
             DecoderSpecs decSpec,
             int[] utdepth)

Constructs a new ForwCompTransf object that operates on the specified source of image data.

Parameters:

imgSrc - The source from where to get the data to be transformed

decSpec - The decoder specifications

See Also:

BlkImgDataSrc

Method Detail

getParameterInfo

public static String[][] getParameterInfo()

Returns the parameters that are used in this class and implementing classes. It returns a 2D String array. Each of the 1D arrays is for a different option, and they have 4 elements. The first element is the option name, the second one is the synopsis, the third one is a long description of what the parameter is and the fourth is its default value. The synopsis or description may be 'null', in which case it is assumed that there is no synopsis or description of the option, respectively. Null may be returned if no options are supported.

Returns:

the options name, their synopsis and their explanation, or null if no options are supported.

toString

public String toString()

Returns a string with a descriptive text of which inverse component transformation is used. This can be either "Inverse RCT" or "Inverse ICT" or "No component transformation" depending on the current tile.

Overrides:

toString in class Object

Returns:

A descriptive string

isReversible

public boolean isReversible()

Returns true if this transform is reversible in current tile. Reversible component transformations are those which operation can be completely reversed without any loss of information (not even due to rounding).

Returns:

Reversibility of component transformation in current tile

getFixedPoint

public int getFixedPoint(int c)

Returns the position of the fixed point in the specified component. This is the position of the least significant integral (i.e. non-fractional) bit, which is equivalent to the number of fractional bits. For instance, for fixed-point values with 2 fractional bits, 2 is returned. For floating-point data this value does not apply and 0 should be returned. Position 0 is the position of the least significant bit in the data.

This default implementation assumes that the number of fractional bits is not modified by the component mixer.

Specified by:

getFixedPoint in interface BlkImgDataSrc

Parameters:

c - The index of the component.

Returns:

The value of the fixed point position of the source since the color transform does not affect it.

calcMixedBitDepths

public static int[] calcMixedBitDepths(int[] utdepth,
                       int ttype,
                       int[] tdepth)

Calculates the bitdepths of the transformed components, given the bitdepth of the un-transformed components and the component tranformation type.

Parameters:

utdepth - The bitdepth of each un-transformed component

ttype - The type ID of the inverse component tranformation

tdepth - If not null the results are stored in this array, otherwise a new array is allocated and returned.

Returns:

The bitdepth of each transformed component.

getNomRangeBits

public int getNomRangeBits(int c)

Returns the number of bits, referred to as the "range bits", corresponding to the nominal range of the data in the specified component. If this number is b then for unsigned data the nominal range is between 0 and 2^b-1, and for signed data it is between -2^(b-1) and 2^(b-1)-1.

Specified by:

getNomRangeBits in interface ImgData

Overrides:

getNomRangeBits in class ImgDataAdapter

Parameters:

c - The index of the component.

Returns:

The bitdepth of un-transformed component 'c'.

getCompData

public DataBlk getCompData(DataBlk blk,
                  int c)

Apply inverse component transformation associated with the current tile. If no component transformation has been requested by the user, data are not modified.

This method calls the getInternCompData() method, but respects the definitions of the getCompData() method defined in the BlkImgDataSrc interface.

Specified by:

getCompData in interface BlkImgDataSrc

Parameters:

blk - Determines the rectangular area to return, and the data is returned in this object.

c - Index of the output component.

Returns:

The requested DataBlk

See Also:

BlkImgDataSrc.getCompData(jj2000.j2k.image.DataBlk, int)

getInternCompData

public DataBlk getInternCompData(DataBlk blk,
                        int c)

Apply the inverse component transformation associated with the current tile. If no component transformation has been requested by the user, data are not modified. Else, appropriate method is called (invRCT or invICT).

Specified by:

getInternCompData in interface BlkImgDataSrc

Parameters:

blk - Determines the rectangular area to return.

c - Index of the output component.

Returns:

The requested DataBlk

See Also:

invRCT(jj2000.j2k.image.DataBlk, int), invICT(jj2000.j2k.image.DataBlk, int)

invRCT

private DataBlk invRCT(DataBlk blk,
             int c)

Apply inverse component transformation to obtain requested component from specified block of data. Whatever the type of requested DataBlk, it always returns a DataBlkInt.

Parameters:

blk - Determine the rectangular area to return

c - The index of the requested component

Returns:

Data of requested component

invICT

private DataBlk invICT(DataBlk blk,
             int c)

Apply inverse irreversible component transformation to obtain requested component from specified block of data. Whatever the type of requested DataBlk, it always returns a DataBlkFloat.

Parameters:

blk - Determine the rectangular area to return

c - The index of the requested component

Returns:

Data of requested component

setTile

public void setTile(int x,
           int y)

Changes the current tile, given the new indexes. An IllegalArgumentException is thrown if the indexes do not correspond to a valid tile.

This default implementation changes the tile in the source and re-initializes properly component transformation variables..

Specified by:

setTile in interface ImgData

Overrides:

setTile in class ImgDataAdapter

Parameters:

x - The horizontal index of the tile.

y - The vertical index of the new tile.

nextTile

public void nextTile()

Advances to the next tile, in standard scan-line order (by rows then columns). An NoNextElementException is thrown if the current tile is the last one (i.e. there is no next tile).

This default implementation just advances to the next tile in the source and re-initializes properly component transformation variables.

Specified by:

nextTile in interface ImgData

Overrides:

nextTile in class ImgDataAdapter