com.sun.media.imageioimpl.common

Class LZWCompressor

java.lang.Object

com.sun.media.imageioimpl.common.LZWCompressor

public class LZWCompressor
extends Object

Modified from original LZWCompressor to change interface to passing a buffer of data to be compressed.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) BitFile	bf_ output destination for bit codes
(package private) int	clearCode_ reserved clear code based on code size
(package private) int	codeSize_ base underlying code size of data being compressed 8 for TIFF, 1 to 8 for GIF
(package private) int	endOfInfo_ reserved end of data code based on code size
(package private) int	limit_ limit at which current number of bits code size has to be increased
(package private) LZWStringTable	lzss_ general purpose LZW string table
(package private) int	numBits_ current number bits output for each code
(package private) short	prefix_ the prefix code which represents the predecessor string to current input point
(package private) boolean	tiffFudge_ modify the limits of the code values in LZW encoding due to TIFF bug / feature

Constructor Summary

Constructors

Constructor and Description
LZWCompressor(ImageOutputStream out, int codeSize, boolean TIFF)

Method Summary

Modifier and Type	Method and Description
void	compress(byte[] buf, int offset, int length)
void	dump(PrintStream out)
void	flush() Indicate to compressor that no more data to go so write out any remaining buffered data.

Methods inherited from class java.lang.Object

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

Field Detail

codeSize_

int codeSize_

base underlying code size of data being compressed 8 for TIFF, 1 to 8 for GIF

clearCode_

int clearCode_

reserved clear code based on code size

endOfInfo_

int endOfInfo_

reserved end of data code based on code size

numBits_

int numBits_

current number bits output for each code

limit_

int limit_

limit at which current number of bits code size has to be increased

prefix_

short prefix_

the prefix code which represents the predecessor string to current input point

bf_

BitFile bf_

output destination for bit codes

lzss_

LZWStringTable lzss_

general purpose LZW string table

tiffFudge_

boolean tiffFudge_

modify the limits of the code values in LZW encoding due to TIFF bug / feature

Constructor Detail

LZWCompressor

public LZWCompressor(ImageOutputStream out,
                     int codeSize,
                     boolean TIFF)
              throws IOException

Parameters:

out - destination for compressed data

codeSize - the initial code size for the LZW compressor

TIFF - flag indicating that TIFF lzw fudge needs to be applied

Throws:

IOException - if underlying output stream error

Method Detail

compress

public void compress(byte[] buf,
                     int offset,
                     int length)
              throws IOException

Parameters:

buf - data to be compressed to output stream

Throws:

IOException - if underlying output stream error

flush

public void flush()
           throws IOException

Indicate to compressor that no more data to go so write out any remaining buffered data.

Throws:

IOException - if underlying output stream error

dump

public void dump(PrintStream out)