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CSJ2K.j2k.entropy.encoder.EntropyCoder

EntropyCoder Class

This abstract class provides the general interface for block-based entropy encoders. The input to the entropy coder is the quantized wavelet coefficients, or codewords, represented in sign magnitude. The output is a compressed code-block with rate-distortion information.

       <p>The source of data for objects of this class are 'CBlkQuantDataSrcEnc'
       objects.</p><p>For more details on the sign magnitude representation used see the
       Quantizer class.</p><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 entropy
       coder. If that is not the case for a particular implementation then the
       methods should be overriden.</p>
Inheritance
object
ImgDataAdapter
EntropyCoder
StdEntropyCoder
Implements
Namespace: CSJ2K.j2k.entropy.encoder
Assembly: C1.WPF.PdfViewer.4.6.2.dll
Syntax
public abstract class EntropyCoder : ImgDataAdapter, CodedCBlkDataSrcEnc, ForwWTDataProps, ImgData

Constructors

Name Description
EntropyCoder(CBlkQuantDataSrcEnc)

Initializes the source of quantized wavelet coefficients.

Fields

Name Description
OPT_PREFIX

The prefix for entropy coder options: 'C'
src

The source of quantized wavelet coefficients

Properties

Name Description
CbULX

Returns the horizontal offset of the code-block partition. Allowable values are 0 and 1, nothing else.
CbULY

Returns the vertical offset of the code-block partition. 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, 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.

Methods

Name Description
createInstance(CBlkQuantDataSrcEnc, ParameterList, CBlkSizeSpec, PrecinctSizeSpec, StringSpec, StringSpec, StringSpec, StringSpec, StringSpec, StringSpec, StringSpec)

Creates a EntropyCoder object for the appropriate entropy coding parameters in the parameter list 'pl', and having 'src' as the source of quantized data.
getAnSubbandTree(int, int)

Returns a reference to the root of subband tree structure representing the subband decomposition for the specified tile-component.
getCBlkHeight(int, int)

Returns the code-block height for the specified tile and component.
getCBlkWidth(int, int)

Returns the code-block width for the specified tile and component.
getNextCodeBlock(int, CBlkRateDistStats)

Returns the next coded 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'.

       <p>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.</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.</p>
getPPX(int, int, int)

Returns the width of a packet for the specified tile-component and resolution level.
getPPY(int, int, int)

Returns the height of a packet for the specified tile-component and resolution level.
isReversible(int, int)

Returns the reversibility of the given tile-component. Data is reversible when it is suitable for lossless and lossy-to-lossless compression.
precinctPartitionUsed(int, int)

Returns true if the precinct partition is used for the specified component and tile, returns false otherwise

See Also