TER.TERcoder.SegmentCoder
Class CodeBlockAC

java.lang.Object
  TER.TERcoder.SegmentCoder.CodeBlockAC

public class CodeBlockAC
extends java.lang.Object

This class codes as many bitplanes of a block of AC components as the user requires. Usage example:
construct
setParameters
run
get functions

Version:

1.1

Author:

Group on Interactive Coding of Images (GICI)

Field Summary

(package private) int	bitDepthAC_Block Determines, for each block, the number of bits needed to represent the magnitude of AC components
(package private) int	blockNumber Indicates the position of the gaggle inside the channel
(package private) byte[][][][]	blockStatus This array contains the status of each of the components in the block.
(package private) int[]	BP For each family and generation indicates the number of bitplanes that are necessary zero due the weighting stage
(package private) int	channel Indicates the channel where the block belongs
(package private) int[]	codeLength Stores for each of the entropy coder options the number of bits required to encode the gaggle.
(package private) boolean	computeDistortion Indicates whether the decrease of the distortion must be computed in order to stop coding process at a given point.
(package private) byte[]	D Indicate whether the descendants (all the components except the parents) are or have been significant for each of the families.
(package private) DistortionCompute	distortion Definition in SegmentCode2D.distortion
(package private) byte	Ds Indicate whether the descendants (all the components except the parents) are or have been significant.
(package private) int	entropyCode Indicates how the obtained code stream is going to be entropy encoded.
(package private) float[][][]	imageSamples Definition in Coder.imageSamplesFloat
(package private) boolean	parametersSet To know if parameters are set.
(package private) BitStream[]	refinementAC This array contains the refinement bits of the block in a bit plane.
(package private) int	resolutionLevels Definition in SegmentCode2D.resolutionLevels
(package private) byte[][]	significantPiramid Represents the significance of each subband of the block (significantPiramid[level of resolution][family])
(package private) ByteStream[][][]	sortingAC This array contains the significance (and its contexts if needed) of a block in a bitplane.
(package private) int	threshold
(package private) int[]	WTLevels Definition in ForwardWaveletTransform.WTLevels
(package private) int[][]	xInit Indicates the initial row of each of the subbands of the block inside the whole image.
(package private) int[][]	yInit Indicates the initial column of each of the subbands of the block inside the whole image.

Constructor Summary

CodeBlockAC(float[][][] imageSamples, int[] resolutionLevels)
Constructor that receives the values of the block to be further encoded.

Method Summary

private boolean	bitPlaneOfZeros(int rLevel, int subband, int bitPlane) This function indicates if the bits of the coefficients are necessarily zero due to the subband scaling operation
private void	codeSquare(int bitPlane, int rLevel, int subband) This function create the words needed to encode each of the squares (subbands) contained in a block.
private int[][]	codeWords(int[][] initialWords, int bitPlane, int rLevel, int subband, int pass) Given a set of words or transition words it encodes it for a given pass.
byte[][][][]	getBlockStatus()
int[]	getCodeLength()
byte[]	getD()
byte	getDs()
byte	getRecommededContext(int stage, int length, boolean impossiblePattern) This function indicates which context correspond to each coded word given its stage, lentgh, ...
BitStream[]	getRefinementAC()
private void	initBlockStatus() Initialize the array with contains the status of each AC component of the block
private void	initStreams(int bitPlane) Initialize the bit streams and the byte streams used to store the significance block and to store the the contexts of the encoded words to be further entropy encoded.
void	refinementCoding(int bitPlane) Perform the refinement of the components of the block for the given bitPlane
ByteStream[][][]	run(int bitPlane) Runs the block coder algorithm
void	setParameters(int[] WTLevels, int resolutionLevels, int channel, int blockNumber, byte[][][][] blockStatus, int bitDepthAC_Block, int entropyAC, int[] BP, DistortionCompute distortion, byte Ds, byte[] D, int[] codeLength) Set the parameters used to code a block
void	significanceCoding(int bitPlane) The significance of the block is encoded for the given bitPlane.
void	updateLeastSignificantBP(int bitPlane) This function update the blockStatus for the values that should not be further encoded due to the weighting step for a given bitplane
private void	updateLengthEntropyEncoder(int word, byte context) This function computes the lenght that would use any of the entropy encoding options.
private void	updateStreams(int rLevel, int subband, int pass, int word, int length, int stage, boolean impossiblePattern) Here are stored words and additional information which is needed to entropy encode each block

Methods inherited from class java.lang.Object

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

Field Detail

sortingAC

ByteStream[][][] sortingAC

This array contains the significance (and its contexts if needed) of a block in a bitplane. It is structured as follows: stream[resolution level][family][coding pass]

blockStatus

byte[][][][] blockStatus

This array contains the status of each of the components in the block. They are structured as follows: blockStatus[resolution level][family][y][x]

bitDepthAC_Block

int bitDepthAC_Block

Determines, for each block, the number of bits needed to represent the magnitude of AC components

resolutionLevels

int resolutionLevels

Definition in SegmentCode2D.resolutionLevels

entropyCode

int entropyCode

Indicates how the obtained code stream is going to be entropy encoded.

refinementAC

BitStream[] refinementAC

This array contains the refinement bits of the block in a bit plane. It is structured as follows: refinementAC[level of resolution]

distortion

DistortionCompute distortion

Definition in SegmentCode2D.distortion

Ds

byte Ds

Indicate whether the descendants (all the components except the parents) are or have been significant. Valid values are:

• 0 - Descendants are not significant
• 1 - Descendant become significant at this bitplane
• 2 - Descendant have been found significant in previous bitplanes

D

byte[] D

Indicate whether the descendants (all the components except the parents) are or have been significant for each of the families. That means, D[i] indicate the significance of the descendant in the family 'i'. Valid values are:

• 0 - Descendants are not significant
• 1 - Descendant become significant at this bitplane
• 2 - Descendant have been found significant in previous bitplanes

BP

int[] BP

For each family and generation indicates the number of bitplanes that are necessary zero due the weighting stage

Negative values are not allowed.

parametersSet

boolean parametersSet

To know if parameters are set.

True indicates that they are set otherwise false.

codeLength

int[] codeLength

Stores for each of the entropy coder options the number of bits required to encode the gaggle.

Negative values are not allowed.

imageSamples

float[][][] imageSamples

Definition in Coder.imageSamplesFloat

WTLevels

int[] WTLevels

Definition in ForwardWaveletTransform.WTLevels

channel

int channel

Indicates the channel where the block belongs

blockNumber

int blockNumber

Indicates the position of the gaggle inside the channel

xInit

int[][] xInit

Indicates the initial row of each of the subbands of the block inside the whole image.

yInit

int[][] yInit

Indicates the initial column of each of the subbands of the block inside the whole image.

significantPiramid

byte[][] significantPiramid

Represents the significance of each subband of the block (significantPiramid[level of resolution][family])

computeDistortion

boolean computeDistortion

Indicates whether the decrease of the distortion must be computed in order to stop coding process at a given point.

threshold

int threshold

Constructor Detail

CodeBlockAC

public CodeBlockAC(float[][][] imageSamples,
                   int[] resolutionLevels)

Constructor that receives the values of the block to be further encoded.

Parameters:

imageSamples - Coder.imageSamplesFloat

resolutionLevels - SegmentCode2D.resolutionLevels

Method Detail

setParameters

public void setParameters(int[] WTLevels,
                          int resolutionLevels,
                          int channel,
                          int blockNumber,
                          byte[][][][] blockStatus,
                          int bitDepthAC_Block,
                          int entropyAC,
                          int[] BP,
                          DistortionCompute distortion,
                          byte Ds,
                          byte[] D,
                          int[] codeLength)

Set the parameters used to code a block

Parameters:

WTLevels - definition in ForwardWaveletTransform.WTLevels

resolutionLevels - definition in SegmentCode2D.resolutionLevels

channel - definition in channel

blockNumber - definition in blockNumber

blockStatus - definition in blockStatus

bitDepthAC_Block - definition in bitDepthAC_Block

entropyAC - definition in EncodeGaggleAC.entropyAC

BP - definition in BP

distortion - distortion

Ds - Ds

D - D

codeLength - codeLength

run

public ByteStream[][][] run(int bitPlane)
                     throws java.lang.Exception

Runs the block coder algorithm

Parameters:

bitPlane - indicates the bitplane that must be coded

Returns:

an array the stream of the coded block for the given bitplane structured as follows: [level of resolution (parents, children,...)][subband or family][coding pass]

Throws:

java.lang.Exception - when something goes wrong and block coding must be stopped

significanceCoding

public void significanceCoding(int bitPlane)

The significance of the block is encoded for the given bitPlane.

Parameters:

bitPlane - indicates the bitplane that must be coded

bitPlaneOfZeros

private boolean bitPlaneOfZeros(int rLevel,
                                int subband,
                                int bitPlane)

This function indicates if the bits of the coefficients are necessarily zero due to the subband scaling operation

Parameters:

rLevel - indicates the resolution level of the subband to be encoded

subband - determines the subband once is known the resolution level

bitPlane - indicates the bitplane that is being encoded

Returns:

a boolean that indicates if the coefficients of this subband should be taken into account for significance encoding purposes

codeSquare

private void codeSquare(int bitPlane,
                        int rLevel,
                        int subband)

This function create the words needed to encode each of the squares (subbands) contained in a block.

Parameters:

bitPlane - indicates the bitplane that is being encoded

rLevel - indicates the resolution level of the subband to be encoded

subband - determines the subband once is known the resolution level

codeWords

private int[][] codeWords(int[][] initialWords,
                          int bitPlane,
                          int rLevel,
                          int subband,
                          int pass)

Given a set of words or transition words it encodes it for a given pass. It also computes the words required for the previous pass

Parameters:

initialWords - contains the set of words to be encoded

bitPlane - indicates the bitplane that is being encoded

rLevel - indicates the resolution level of the subband to be encoded

subband - determines the subband once is known the resolution level

pass - indicates the coding pass that is being encoded

Returns:

the set of words required for encoding next pass

updateStreams

private void updateStreams(int rLevel,
                           int subband,
                           int pass,
                           int word,
                           int length,
                           int stage,
                           boolean impossiblePattern)

Here are stored words and additional information which is needed to entropy encode each block

Parameters:

rLevel - indicates the resolution level of the subband to be encoded

subband - determines the subband once is known the resolution level

pass - indicates the coding pass that is being encoded

word - contains a word that has been encoded

length - indicates the lenght of the word to be encoded. Valid values are between 1 and 4.

stage - indicates if the word corresponds to the significance encoding, the sign encoding or the refinement.

• -2- Ds coding
• -1- significance of components
• 0 - significance of a set of components
• 1 - sign
• 2 - refinement

impossiblePattern - indicates if all zeros value if possible

refinementCoding

public void refinementCoding(int bitPlane)

Perform the refinement of the components of the block for the given bitPlane

Parameters:

bitPlane - indicates the bitplane that is being encoded

updateLengthEntropyEncoder

private void updateLengthEntropyEncoder(int word,
                                        byte context)

This function computes the lenght that would use any of the entropy encoding options.

Parameters:

word - contains a word that has been encoded

context - indicates the kind of word to be encoded, i.e. the lenght and the encoding pass

initBlockStatus

private void initBlockStatus()

Initialize the array with contains the status of each AC component of the block

initStreams

private void initStreams(int bitPlane)

Initialize the bit streams and the byte streams used to store the significance block and to store the the contexts of the encoded words to be further entropy encoded.

Parameters:

bitPlane - indicates the bitplane that is going to be encoded

updateLeastSignificantBP

public void updateLeastSignificantBP(int bitPlane)

This function update the blockStatus for the values that should not be further encoded due to the weighting step for a given bitplane

Parameters:

bitPlane - indicates the bitplane for which the blockStatus is updated

getRecommededContext

public byte getRecommededContext(int stage,
                                 int length,
                                 boolean impossiblePattern)

This function indicates which context correspond to each coded word given its stage, lentgh, ...

Parameters:

stage - indicates if the word corresponds to the significance encoding, the sign encoding or the refinement.

• -2- Ds coding
• -1- significance of components
• 0 - significance of a set of components
• 1 - sign
• 2 - refinement

length - indicates the lenght of the word to be encoded. Valid values are between 1 and 4.

impossiblePattern - indicates if all zeros value if possible.

Returns:

a byte that contains the context for entropy encoding the word.

getBlockStatus

public byte[][][][] getBlockStatus()

getD

public byte[] getD()

getDs

public byte getDs()

getRefinementAC

public BitStream[] getRefinementAC()

getCodeLength

public int[] getCodeLength()