CBlkWTDataSrc

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jj2000.j2k.wavelet.analysis
Interface CBlkWTDataSrc

All Superinterfaces:: ForwWTDataProps, ImgData

All Known Implementing Classes:: ForwardWT

public interface CBlkWTDataSrc
extends ForwWTDataProps

This abstract class defines methods to transfer wavelet data in a code-block by code-block basis. In each call to 'getNextCodeBlock()' or 'getNextInternCodeBlock()' a new code-block is returned. The code-blocks are returned in no specific order.

This class is the source of data for the quantizer. See the 'Quantizer' class.

Note that no more of one object may request data, otherwise one object would get some of the data and another one another part, in no defined manner.

See Also:: ForwWTDataProps, WaveletTransform, CBlkQuantDataSrcEnc, Quantizer

Method Summary

int getDataType(int t, int c)
          Return the data type of this CBlkWTDataSrc for the given component in the current tile.

int getFixedPoint(int c)
          Returns the position of the fixed point in the specified component, or equivalently the number of fractional bits.

CBlkWTData getNextCodeBlock(int c, CBlkWTData cblk)
          Returns the next code-block in the current tile for the specified component, as a copy (see below).

CBlkWTData getNextInternCodeBlock(int c, CBlkWTData cblk)
          Returns the next code-block in the current tile for the specified component.

Methods inherited from interface jj2000.j2k.wavelet.analysis.ForwWTDataProps

getAnSubbandTree, getCbULX, getCbULY, isReversible

Methods inherited from interface jj2000.j2k.image.ImgData

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

Method Detail

getFixedPoint

public 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.

getDataType

public int getDataType(int t,
                       int c)

Return the data type of this CBlkWTDataSrc for the given component in the current tile. Its value should be either DataBlk.TYPE_INT or DataBlk.TYPE_FLOAT but can change according to the current tile-component.

Parameters:: t - Tile index; c - Component index
Returns:: Current data type

getNextCodeBlock

public CBlkWTData getNextCodeBlock(int c,
                                   CBlkWTData cblk)

Returns the next code-block in the current tile for the specified component, as a copy (see below). The order in which code-blocks are returned is not specified. However each code-block is returned only once and all code-blocks will be returned if the method is called 'N' times, where 'N' is the number of code-blocks in the tile. After all the code-blocks have been returned for the current tile calls to this method will return 'null'.

When changing the current tile (through 'setTile()' or 'nextTile()') this method will always return the first code-block, as if this method was never called before for the new current tile.

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. The 'magbits' of the returned data is not set by this method and should be ignored. See the 'CBlkWTData' class.

The 'ulx' and 'uly' members of the returned 'CBlkWTData' object contain the coordinates of the top-left corner of the block, with respect to the tile, not the subband.

Parameters:: c - The component for which to return the next code-block.; 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 'c', or null if all code-blocks for the current tile have been returned.
See Also:: CBlkWTData

getNextInternCodeBlock

public CBlkWTData getNextInternCodeBlock(int c,
                                         CBlkWTData cblk)

Returns the next code-block in the current tile for the specified component. The order in which code-blocks are returned is not specified. However each code-block is returned only once and all code-blocks will be returned if the method is called 'N' times, where 'N' is the number of code-blocks in the tile. After all the code-blocks have been returned for the current tile calls to this method will return 'null'.