org.jpedal.sun.TIFFLZWDecoder Maven / Gradle / Ivy
/*
* Copyright (c) 2001 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduct the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
* IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
* NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
* LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
* OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
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* CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
* OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that Software is not designed,licensed or intended for use in
* the design, construction, operation or maintenance of any nuclear facility.
*/
/**
* A class for performing LZW decoding.
*
*
*/
package org.jpedal.sun;
import org.jpedal.utils.LogWriter;
public class TIFFLZWDecoder
{
final int[] andTable =
{
511, 1023, 2047, 4095
};
int nextBits;
int nextData;
int tableIndex, bitsToGet = 9;
int bytePointer;
int dstIndex;
byte stringTable[][];
byte data[], uncompData[];
// Returns the next 9, 10, 11 or 12 bits
public int getNextCode()
{
// Attempt to get the next code. The exception is caught to make
// this robust to cases wherein the EndOfInformation code has been
// omitted from a strip. Examples of such cases have been observed
// in practice.
try
{
nextData = ( nextData << 8 ) | ( data[bytePointer++] & 0xff );
nextBits += 8;
if( nextBits < bitsToGet )
{
nextData = ( nextData << 8 ) | ( data[bytePointer++] & 0xff );
nextBits += 8;
}
final int code = ( nextData >> ( nextBits - bitsToGet ) ) & andTable[bitsToGet - 9];
nextBits -= bitsToGet;
return code;
}
catch( final ArrayIndexOutOfBoundsException e )
{
if(LogWriter.isOutput()) {
LogWriter.writeLog("LZW out of bounds "+e);
}
// Strip not terminated as expected: return EndOfInformation code.
return 257;
}
}
/**
* Append newString to the end of oldString.
*/
public static byte[] composeString( final byte[] oldString, final byte newString )
{
final int length = oldString.length;
final byte[] string = new byte[length + 1];
System.arraycopy( oldString, 0, string, 0, length );
string[length] = newString;
return string;
}
/**
* Method to decode LZW compressed data.
*
* @param data The compressed data.
* @param uncompData Array to return the uncompressed data in.
* @param h The number of rows the compressed data contains.
*/
public void decode( final byte[] data, final byte[] uncompData)
{
if( data[0] == (byte)0x00 && data[1] == (byte)0x01 ) {
throw new UnsupportedOperationException(JaiI18N.getString("TIFFLZWDecoder0"));
}
initializeStringTable();
this.data = data;
this.uncompData = uncompData;
// Initialize pointers
bytePointer = 0;
dstIndex = 0;
nextData = 0;
nextBits = 0;
int code, oldCode = 0;
byte string[];
while( ( ( code = getNextCode() ) != 257 ) && dstIndex < uncompData.length )
{
if( code == 256 )
{
initializeStringTable();
code = getNextCode();
if( code == 257 ) {
break;
}
writeString( stringTable[code] );
oldCode = code;
}
else
{
if( code < tableIndex )
{
string = stringTable[code];
writeString( string );
addStringToTable( stringTable[oldCode], string[0] );
oldCode = code;
}
else
{
string = stringTable[oldCode];
string = composeString( string, string[0] );
writeString( string );
addStringToTable( string );
oldCode = code;
}
}
}
/**
// Horizontal Differencing Predictor
if( predictor == 2 )
{
int count;
for( int j = 0;j < h;j++ )
{
count = samplesPerPixel * ( j * w + 1 );
for( int i = samplesPerPixel;i < w * samplesPerPixel;i++ )
{
uncompData[count] += uncompData[count - samplesPerPixel];
count++;
}
}
}*/
}
/**
* Initialize the string table.
*/
public void initializeStringTable()
{
stringTable = new byte[4096][];
for( int i = 0;i < 256;i++ )
{
stringTable[i] = new byte[1];
stringTable[i][0] = (byte)i;
}
tableIndex = 258;
bitsToGet = 9;
}
/**
* Write out the string just uncompressed.
*/
public void writeString( final byte[] string )
{
for (final byte aString : string) {
uncompData[dstIndex++] = aString;
}
}
/**
* Add a new string to the string table.
*/
public void addStringToTable( final byte[] oldString, final byte newString )
{
final int length = oldString.length;
final byte[] string = new byte[length + 1];
System.arraycopy( oldString, 0, string, 0, length );
string[length] = newString;
// Add this new String to the table
stringTable[tableIndex++] = string;
if( tableIndex == 511 ) {
bitsToGet = 10;
} else
if( tableIndex == 1023 ) {
bitsToGet = 11;
} else
if( tableIndex == 2047 ) {
bitsToGet = 12;
}
}
/**
* Add a new string to the string table.
*/
public void addStringToTable( final byte[] string )
{
// Add this new String to the table
stringTable[tableIndex++] = string;
if( tableIndex == 511 ) {
bitsToGet = 10;
} else
if( tableIndex == 1023 ) {
bitsToGet = 11;
} else
if( tableIndex == 2047 ) {
bitsToGet = 12;
}
}
}
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