Dequantizer Class

This is the abstract class from which all dequantizers must inherit. This class has the concept of a current tile and all operations are performed on the current tile.

       <p>This class provides default implemenations for most of the methods
       (wherever it makes sense), under the assumption that the image and
       component dimensions, and the tiles, are not modifed by the dequantizer. If
       that is not the case for a particular implementation then the methods
       should be overriden.</p>

       <p>Sign magnitude representation is used (instead of two's complement) for
       the input data. The most significant bit is used for the sign (0 if
       positive, 1 if negative). Then the magnitude of the quantized coefficient
       is stored in the next most significat bits. The most significant magnitude
       bit corresponds to the most significant bit-plane and so on.</p>

       <p>The output data is either in floating-point, or in fixed-point two's
       complement. In case of floating-point data the the value returned by
       getFixedPoint() must be 0. If the case of fixed-point data the number of
       fractional bits must be defined at the constructor of the implementing
       class and all operations must be performed accordingly. Each component may
       have a different number of fractional bits.</p>

Inheritance

object

MultiResImgDataAdapter

Dequantizer

StdDequantizer

Implements

CBlkWTDataSrcDec

InvWTData

MultiResImgData

Namespace: CSJ2K.j2k.quantization.dequantizer

Assembly: C1.C1Pdf.4.8.dll

Syntax

public abstract class Dequantizer : MultiResImgDataAdapter, CBlkWTDataSrcDec, InvWTData, MultiResImgData

Public MustInherit Class Dequantizer
    Inherits MultiResImgDataAdapter
    Implements CBlkWTDataSrcDec, InvWTData, MultiResImgData

Constructors

Name	Description
Dequantizer(CBlkQuantDataSrcDec, int[], DecoderSpecs)	Initializes the source of compressed data.

Fields

Name	Description
OPT_PREFIX	The prefix for dequantizer options: 'Q'
rb	The "range bits" for each transformed component
src	The entropy decoder from where to get the quantized data (the source).
utrb	The "range bits" for each un-transformed component

Properties

Name	Description
CbULX	Returns the horizontal code-block partition origin. Allowable values are 0 and 1, nothing else.
CbULY	Returns the vertical code-block partition origin. Allowable values are 0 and 1, nothing else.
ParameterInfo	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 3 elements. The first element is the option name, the second one is the synopsis and the third one is a long description of what the parameter is. 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.

Methods

Name	Description
getCodeBlock(int, int, int, SubbandSyn, DataBlk)	Returns the specified code-block in the current tile for the specified component, as a copy (see below). <p>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.</p> <p>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.</p>
getFixedPoint(int)	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.
getInternCodeBlock(int, int, int, SubbandSyn, DataBlk)	Returns the specified code-block in the current tile for the specified component (as a reference or copy). <p>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.</p> <p>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.</p>
getNomRangeBits(int)
getSynSubbandTree(int, int)	Returns the specified synthesis subband tree
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). `<p>This default implementation just changes the tile in the source.</p>`
setTile(int, int)	Changes the current tile, given the new indexes. An IllegalArgumentException is thrown if the indexes do not correspond to a valid tile. `<p>This default implementation just changes the tile in the source.</p>`