jj2000.j2k.wavelet.synthesis

Interface CBlkWTDataSrcDec

All Superinterfaces:

InvWTData, MultiResImgData

All Known Implementing Classes:

Dequantizer, StdDequantizer

public interface CBlkWTDataSrcDec
extends InvWTData

This abstract class defines methods to transfer wavelet data in a code-block by code-block basis, for the decoder side. In each call to 'getCodeBlock()' or 'getInternCodeBlock()' a new code-block is returned. The code-blocks are returned in no specific order.

This class is the source of data, in general, for the inverse wavelet transforms. See the 'InverseWT' class.

See Also:

InvWTData, WaveletTransform, CBlkQuantDataSrcDec, InverseWT

Method Summary

Modifier and Type	Method and Description
DataBlk	getCodeBlock(int c, int m, int n, SubbandSyn sb, DataBlk cblk) Returns the specified code-block in the current tile for the specified component, as a copy (see below).
int	getFixedPoint(int c) Returns the position of the fixed point in the specified component, or equivalently the number of fractional bits.
DataBlk	getInternCodeBlock(int c, int m, int n, SubbandSyn sb, DataBlk cblk) Returns the specified code-block in the current tile for the specified component (as a reference or copy).
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.

Methods inherited from interface jj2000.j2k.wavelet.synthesis.InvWTData

getCbULX, getCbULY, getSynSubbandTree

Methods inherited from interface jj2000.j2k.wavelet.synthesis.MultiResImgData

getCompImgHeight, getCompImgWidth, getCompSubsX, getCompSubsY, getImgHeight, getImgULX, getImgULY, getImgWidth, getNomTileHeight, getNomTileWidth, getNumComps, getNumTiles, getNumTiles, getResULX, getResULY, getTile, getTileCompHeight, getTileCompWidth, getTileHeight, getTileIdx, getTilePartULX, getTilePartULY, getTileWidth, nextTile, setTile

Method Detail

getNomRangeBits

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.

The returned value corresponds to the nominal dynamic range of the reconstructed image data, not of the wavelet coefficients themselves. This is because different subbands have different gains and thus different nominal ranges. To have an idea of the nominal range in each subband the subband analysis gain value from the subband tree structure, returned by the 'getSubbandTree()' method, can be used. See the 'Subband' class for more details.

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.

Parameters:

c - The index of the component

Returns:

The number of bits corresponding to the nominal range of the data.

See Also:

Subband

getFixedPoint

int getFixedPoint(int c)

Returns the position of the fixed point in the specified component, or equivalently the number of fractional bits. 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.

Parameters:

c - The index of the component.

Returns:

The position of the fixed-point, which is the same as the number of fractional bits. For floating-point data 0 is returned.

getCodeBlock

DataBlk getCodeBlock(int c,
                     int m,
                     int n,
                     SubbandSyn sb,
                     DataBlk cblk)

Returns the specified code-block in the current tile for the specified component, as a copy (see below).

The returned code-block may be progressive, which is indicated by the 'progressive' variable of the returned 'DataBlk' object. If a code-block is progressive it means that in a later request to this method for the same code-block it is possible to retrieve data which is a better approximation, since meanwhile more data to decode for the code-block could have been received. If the code-block is not progressive then later calls to this method for the same code-block will return the exact same data values.

The data returned by this method is always a copy of the internal data of this object, if any, and it can be modified "in place" without any problems after being returned. The 'offset' of the returned data is 0, and the 'scanw' is the same as the code-block width. See the 'DataBlk' class.

Parameters:

c - The component for which to return the next code-block.

m - The vertical index of the code-block to return, in the specified subband.

n - The horizontal index of the code-block to return, in the specified subband.

sb - The subband in which the code-block to return is.

cblk - If non-null this object will be used to return the new code-block. If null a new one will be allocated and returned. If the "data" array of the object is non-null it will be reused, if possible, to return the data.

Returns:

The next code-block in the current tile for component 'n', or null if all code-blocks for the current tile have been returned.

See Also:

DataBlk

getInternCodeBlock

DataBlk getInternCodeBlock(int c,
                           int m,
                           int n,
                           SubbandSyn sb,
                           DataBlk cblk)

Returns the specified code-block in the current tile for the specified component (as a reference or copy).

The returned code-block may be progressive, which is indicated by the 'progressive' variable of the returned 'DataBlk' object. If a code-block is progressive it means that in a later request to this method for the same code-block it is possible to retrieve data which is a better approximation, since meanwhile more data to decode for the code-block could have been received. If the code-block is not progressive then later calls to this method for the same code-block will return the exact same data values.

The data returned by this method can be the data in the internal buffer of this object, if any, and thus can not be modified by the caller. The 'offset' and 'scanw' of the returned data can be arbitrary. See the 'DataBlk' class.

Parameters:

c - The component for which to return the next code-block.

m - The vertical index of the code-block to return, in the specified subband.

n - The horizontal index of the code-block to return, in the specified subband.

sb - The subband in which the code-block to return is.

cblk - If non-null this object will be used to return the new code-block. If null a new one will be allocated and returned. If the "data" array of the object is non-null it will be reused, if possible, to return the data.

Returns:

The next code-block in the current tile for component 'n', or null if all code-blocks for the current tile have been returned.

See Also:

DataBlk