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The Apache PDFBox library is an open source Java tool for working with PDF documents.
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* $Id: FillOrderChangeInputStream.java 1156213 2011-08-10 15:06:20Z jeremias $ */
package org.apache.pdfbox.io.ccitt;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
/**
* This filtering input stream does a fill order change required for certain TIFF images.
* @version $Revision$
*/
public class FillOrderChangeInputStream extends FilterInputStream
{
/**
* Main constructor.
* @param in the underlying input stream
*/
public FillOrderChangeInputStream(InputStream in)
{
super(in);
}
/** {@inheritDoc} */
public int read(byte[] b, int off, int len) throws IOException
{
int result = super.read(b, off, len);
if (result > 0)
{
int endpos = off + result;
for (int i = off; i < endpos; i++)
{
b[i] = FLIP_TABLE[b[i] & 0xff];
}
}
return result;
}
/** {@inheritDoc} */
public int read() throws IOException
{
int b = super.read();
if (b < 0)
{
return b;
}
else
{
return FLIP_TABLE[b] & 0xff;
}
}
// Table to be used when fillOrder = 2, for flipping bytes.
// Copied from the TIFFFaxDecoder class
private static final byte[] FLIP_TABLE = {
0, -128, 64, -64, 32, -96, 96, -32,
16, -112, 80, -48, 48, -80, 112, -16,
8, -120, 72, -56, 40, -88, 104, -24,
24, -104, 88, -40, 56, -72, 120, -8,
4, -124, 68, -60, 36, -92, 100, -28,
20, -108, 84, -44, 52, -76, 116, -12,
12, -116, 76, -52, 44, -84, 108, -20,
28, -100, 92, -36, 60, -68, 124, -4,
2, -126, 66, -62, 34, -94, 98, -30,
18, -110, 82, -46, 50, -78, 114, -14,
10, -118, 74, -54, 42, -86, 106, -22,
26, -102, 90, -38, 58, -70, 122, -6,
6, -122, 70, -58, 38, -90, 102, -26,
22, -106, 86, -42, 54, -74, 118, -10,
14, -114, 78, -50, 46, -82, 110, -18,
30, -98, 94, -34, 62, -66, 126, -2,
1, -127, 65, -63, 33, -95, 97, -31,
17, -111, 81, -47, 49, -79, 113, -15,
9, -119, 73, -55, 41, -87, 105, -23,
25, -103, 89, -39, 57, -71, 121, -7,
5, -123, 69, -59, 37, -91, 101, -27,
21, -107, 85, -43, 53, -75, 117, -11,
13, -115, 77, -51, 45, -83, 109, -19,
29, -99, 93, -35, 61, -67, 125, -3,
3, -125, 67, -61, 35, -93, 99, -29,
19, -109, 83, -45, 51, -77, 115, -13,
11, -117, 75, -53, 43, -85, 107, -21,
27, -101, 91, -37, 59, -69, 123, -5,
7, -121, 71, -57, 39, -89, 103, -25,
23, -105, 87, -41, 55, -73, 119, -9,
15, -113, 79, -49, 47, -81, 111, -17,
31, -97, 95, -33, 63, -65, 127, -1,
};
// end
}