Package jj2000.j2k.codestream.writer
Class HeaderEncoder
java.lang.Object
jj2000.j2k.codestream.writer.HeaderEncoder
- All Implemented Interfaces:
Markers,StdEntropyCoderOptions
This class writes almost of the markers and marker segments in main header
and in tile-part headers. It is created by the run() method of the Encoder
instance.
A marker segment includes a marker and eventually marker segment parameters. It is designed by the three letter code of the marker associated with the marker segment. JPEG 2000 part I defines 6 types of markers:
- Delimiting : SOC,SOT,SOD,EOC (written in FileCodestreamWriter).
- Fixed information: SIZ.
- Functional: COD,COC,RGN,QCD,QCC,POC.
- In bit-stream: SOP,EPH.
- Pointer: TLM,PLM,PLT,PPM,PPT.
- Informational: CRG,COM.
Main Header is written when Encoder instance calls encodeMainHeader whereas tile-part headers are written when the EBCOTRateAllocator instance calls encodeTilePartHeader.
- See Also:
-
Field Summary
FieldsModifier and TypeFieldDescriptionprotected ByteArrayOutputStreamThe ByteArrayOutputStream to store header data.protected ForwardWTReference to the DWT moduleprotected DataOutputStreamThe DataOutputStream to store header data.protected boolean[]An array specifying, for each component,if the data was signed or notprotected intThe number of components in the imageprotected ImgDataThe image data reader.protected PostCompRateAllocatorReference to the rate allocatorprotected ROIScalerReference to the ROI moduleprotected TilerReference to the tiler moduleprotected J2KImageWriteParamJavaThe encoder specificationsFields inherited from interface jj2000.j2k.codestream.Markers
COC, COD, COM, CRG, EOC, EPH, EPH_LENGTH, ERS_SEG_SYMBOLS, ERS_SOP, MAX_COMP_BITDEPTH, MAX_LPPM, MAX_LPPT, PLM, PLT, POC, PPM, PPT, PRECINCT_PARTITION_DEF_SIZE, QCC, QCD, RCOM_GEN_USE, RGN, RSIZ_BASELINE, RSIZ_ER_FLAG, RSIZ_ROI, SCOX_HOR_CB_PART, SCOX_PRECINCT_PARTITION, SCOX_USE_EPH, SCOX_USE_SOP, SCOX_VER_CB_PART, SIZ, SOC, SOD, SOP, SOP_LENGTH, SOT, SQCX_EXP_MASK, SQCX_EXP_SHIFT, SQCX_GB_MSK, SQCX_GB_SHIFT, SQCX_NO_QUANTIZATION, SQCX_SCALAR_DERIVED, SQCX_SCALAR_EXPOUNDED, SRGN_IMPLICIT, SSIZ_DEPTH_BITS, TLMFields inherited from interface jj2000.j2k.entropy.StdEntropyCoderOptions
FIRST_BYPASS_PASS_IDX, MAX_CB_AREA, MAX_CB_DIM, MIN_CB_DIM, NUM_EMPTY_PASSES_IN_MS_BP, NUM_NON_BYPASS_MS_BP, NUM_PASSES, OPT_BYPASS, OPT_PRED_TERM, OPT_RESET_MQ, OPT_SEG_SYMBOLS, OPT_TERM_PASS, OPT_VERT_STR_CAUSAL, STRIPE_HEIGHT -
Constructor Summary
ConstructorsConstructorDescriptionHeaderEncoder(ImgData origsrc, boolean[] isorigsig, ForwardWT dwt, Tiler tiler, J2KImageWriteParamJava wp, ROIScaler roiSc, PostCompRateAllocator ralloc) Initializes the header writer with the references to the coding chain. -
Method Summary
Modifier and TypeMethodDescriptionvoidWrite main header.voidencodeTilePartHeader(int tileLength, int tileIdx) Writes tile-part header.protected byte[]Returns the byte-buffer used to store the codestream header.protected intReturns the number of bytes used in the codestream header's buffer.intReturns the length of the header.voidreset()Resets the contents of this HeaderEncoder to its initial state.protected voidwriteCOC(boolean mh, int tileIdx, int compIdx) Writes COC marker segment .protected voidwriteCOD(boolean mh, int tileIdx) Writes COD marker segment.protected voidwriteMainQCC(int compIdx) Writes QCC marker segment in main header.protected voidWrites QCD marker segment in main header.protected voidwritePOC(boolean mh, int tileIdx) Writes POC marker segment.protected voidwriteTileQCC(int t, int compIdx) Writes QCC marker segment in tile header.protected voidwriteTileQCD(int tIdx) Writes QCD marker segment in tile header.voidwriteTo(OutputStream out) Writes the header to the specified OutputStream.voidwriteTo(BinaryDataOutput out) Writes the header to the specified BinaryDataOutput.
-
Field Details
-
nComp
protected int nCompThe number of components in the image -
baos
The ByteArrayOutputStream to store header data. This handler is kept in order to use methods not accessible from a general DataOutputStream. For the other methods, it's better to use variable hbuf.- See Also:
-
hbuf
The DataOutputStream to store header data. This kind of object is useful to write short, int, .... It's constructor takes baos as parameter.- See Also:
-
origSrc
The image data reader. Source of original data info -
isOrigSig
protected boolean[] isOrigSigAn array specifying, for each component,if the data was signed or not -
ralloc
Reference to the rate allocator -
dwt
Reference to the DWT module -
tiler
Reference to the tiler module -
roiSc
Reference to the ROI module -
wp
The encoder specifications
-
-
Constructor Details
-
HeaderEncoder
public HeaderEncoder(ImgData origsrc, boolean[] isorigsig, ForwardWT dwt, Tiler tiler, J2KImageWriteParamJava wp, ROIScaler roiSc, PostCompRateAllocator ralloc) Initializes the header writer with the references to the coding chain.- Parameters:
origsrc- The original image data (before any component mixing, tiling, etc.)isorigsig- An array specifying for each component if it was originally signed or not.dwt- The discrete wavelet transform module.tiler- The tiler module.wp- The encoder specificationsroiSc- The ROI scaler module.ralloc- The post compression rate allocator.
-
-
Method Details
-
reset
public void reset()Resets the contents of this HeaderEncoder to its initial state. It erases all the data in the header buffer and reactualizes the headerLength field of the bit stream writer. -
getBuffer
protected byte[] getBuffer()Returns the byte-buffer used to store the codestream header.- Returns:
- A byte array countaining codestream header
-
getLength
public int getLength()Returns the length of the header.- Returns:
- The length of the header in bytes
-
writeTo
Writes the header to the specified BinaryDataOutput.- Parameters:
out- Where to write the header.- Throws:
IOException
-
getBufferLength
protected int getBufferLength()Returns the number of bytes used in the codestream header's buffer.- Returns:
- Header length in buffer (without any header overhead)
-
writeTo
Writes the header to the specified OutputStream.- Parameters:
out- Where to write the header.- Throws:
IOException
-
writeCOD
Writes COD marker segment. COD is a functional marker segment containing the code style default (coding style, decomposition, layering) used for compressing all the components in an image.The values can be overriden for an individual component by a COC marker in either the main or the tile header.
- Parameters:
mh- Flag indicating whether this marker belongs to the main headertileIdx- Tile index if the marker belongs to a tile-part header- Throws:
IOException- See Also:
-
writeCOC
Writes COC marker segment . It is a functional marker containing the coding style for one component (coding style, decomposition, layering).Its values overrides any value previously set in COD in the main header or in the tile header.
- Parameters:
mh- Flag indicating whether the main header is to be writtentileIdx- Tile indexcompIdx- index of the component which need use of the COC marker segment.- Throws:
IOException- See Also:
-
writeMainQCD
Writes QCD marker segment in main header. QCD is a functional marker segment countaining the quantization default used for compressing all the components in an image. The values can be overriden for an individual component by a QCC marker in either the main or the tile header.- Throws:
IOException
-
writeMainQCC
Writes QCC marker segment in main header. It is a functional marker segment countaining the quantization used for compressing the specified component in an image. The values override for the specified component what was defined by a QCC marker in either the main or the tile header.- Parameters:
compIdx- Index of the component which needs QCC marker segment.- Throws:
IOException
-
writeTileQCD
Writes QCD marker segment in tile header. QCD is a functional marker segment countaining the quantization default used for compressing all the components in an image. The values can be overriden for an individual component by a QCC marker in either the main or the tile header.- Parameters:
tIdx- Tile index- Throws:
IOException
-
writeTileQCC
Writes QCC marker segment in tile header. It is a functional marker segment countaining the quantization used for compressing the specified component in an image. The values override for the specified component what was defined by a QCC marker in either the main or the tile header.- Parameters:
t- Tile indexcompIdx- Index of the component which needs QCC marker segment.- Throws:
IOException
-
writePOC
Writes POC marker segment. POC is a functional marker segment containing the bounds and progression order for any progression order other than default in the codestream.- Parameters:
mh- Flag indicating whether the main header is to be writtentileIdx- Tile index- Throws:
IOException
-
encodeMainHeader
Write main header. JJ2000 main header corresponds to the following sequence of marker segments:- SOC
- SIZ
- COD
- COC (if needed)
- QCD
- QCC (if needed)
- POC (if needed)
- Throws:
IOException
-
encodeTilePartHeader
Writes tile-part header. JJ2000 tile-part header corresponds to the following sequence of marker segments:- SOT
- COD (if needed)
- COC (if needed)
- QCD (if needed)
- QCC (if needed)
- RGN (if needed)
- POC (if needed)
- SOD
- Parameters:
tileLength- The length of the current tile-part.tileIdx- Index of the tile to write- Throws:
IOException
-