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An Open Source JavaFX PDF Viewer
/**
* ===========================================
* Java Pdf Extraction Decoding Access Library
* ===========================================
*
* Project Info: http://www.jpedal.org
* (C) Copyright 1997-2008, IDRsolutions and Contributors.
* Main Developer: Simon Barnett
*
* This file is part of JPedal
*
* Copyright (c) 2008, IDRsolutions
* 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.
* * Redistributions in binary form must reproduce 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 the IDRsolutions nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY IDRsolutions ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL IDRsolutions BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Other JBIG2 image decoding implementations include
* jbig2dec (http://jbig2dec.sourceforge.net/)
* xpdf (http://www.foolabs.com/xpdf/)
*
* The final draft JBIG2 specification can be found at http://www.jpeg.org/public/fcd14492.pdf
*
* All three of the above resources were used in the writing of this software, with methodologies,
* processes and inspiration taken from all three.
*
* ---------------
* GenericRegionSegment.java
* ---------------
*/
package org.jpedal.jbig2.segment.region.generic;
import org.jpedal.jbig2.JBIG2Exception;
import org.jpedal.jbig2.decoders.JBIG2StreamDecoder;
import org.jpedal.jbig2.image.JBIG2Bitmap;
import org.jpedal.jbig2.segment.pageinformation.PageInformationFlags;
import org.jpedal.jbig2.segment.pageinformation.PageInformationSegment;
import org.jpedal.jbig2.segment.region.RegionFlags;
import org.jpedal.jbig2.segment.region.RegionSegment;
import java.io.IOException;
public class GenericRegionSegment extends RegionSegment {
private GenericRegionFlags genericRegionFlags = new GenericRegionFlags();
private boolean inlineImage;
private boolean unknownLength = false;
public GenericRegionSegment(JBIG2StreamDecoder streamDecoder, boolean inlineImage) {
super(streamDecoder);
this.inlineImage = inlineImage;
}
public void readSegment() throws IOException, JBIG2Exception {
if(JBIG2StreamDecoder.debug)
System.out.println("==== Reading Immediate Generic Region ====");
super.readSegment();
/** read text region Segment flags */
readGenericRegionFlags();
boolean useMMR = genericRegionFlags.getFlagValue(GenericRegionFlags.MMR) != 0;
int template = genericRegionFlags.getFlagValue(GenericRegionFlags.GB_TEMPLATE);
short[] genericBAdaptiveTemplateX = new short[4];
short[] genericBAdaptiveTemplateY = new short[4];
if (!useMMR) {
if (template == 0) {
genericBAdaptiveTemplateX[0] = readATValue();
genericBAdaptiveTemplateY[0] = readATValue();
genericBAdaptiveTemplateX[1] = readATValue();
genericBAdaptiveTemplateY[1] = readATValue();
genericBAdaptiveTemplateX[2] = readATValue();
genericBAdaptiveTemplateY[2] = readATValue();
genericBAdaptiveTemplateX[3] = readATValue();
genericBAdaptiveTemplateY[3] = readATValue();
} else {
genericBAdaptiveTemplateX[0] = readATValue();
genericBAdaptiveTemplateY[0] = readATValue();
}
arithmeticDecoder.resetGenericStats(template, null);
arithmeticDecoder.start();
}
boolean typicalPredictionGenericDecodingOn = genericRegionFlags.getFlagValue(GenericRegionFlags.TPGDON) != 0;
int length = segmentHeader.getSegmentDataLength();
if(length == -1) {
/**
* length of data is unknown, so it needs to be determined through examination of the data.
* See 7.2.7 - Segment data length of the JBIG2 specification.
*/
unknownLength = true;
short match1;
short match2;
if(useMMR) {
// look for 0x00 0x00 (0, 0)
match1 = 0;
match2 = 0;
} else {
// look for 0xFF 0xAC (255, 172)
match1 = 255;
match2 = 172;
}
int bytesRead = 0;
while(true) {
short bite1 = decoder.readByte();
bytesRead++;
if(bite1 == match1){
short bite2 = decoder.readByte();
bytesRead++;
if(bite2 == match2){
length = bytesRead - 2;
break;
}
}
}
decoder.movePointer(-bytesRead);
}
JBIG2Bitmap bitmap = new JBIG2Bitmap(regionBitmapWidth, regionBitmapHeight, arithmeticDecoder, huffmanDecoder, mmrDecoder);
bitmap.clear(0);
bitmap.readBitmap(useMMR, template, typicalPredictionGenericDecodingOn, false, null, genericBAdaptiveTemplateX, genericBAdaptiveTemplateY, useMMR ? 0 : length - 18);
if (inlineImage) {
PageInformationSegment pageSegment = decoder.findPageSegement(segmentHeader.getPageAssociation());
JBIG2Bitmap pageBitmap = pageSegment.getPageBitmap();
int extCombOp = regionFlags.getFlagValue(RegionFlags.EXTERNAL_COMBINATION_OPERATOR);
if(pageSegment.getPageBitmapHeight() == -1 && regionBitmapYLocation + regionBitmapHeight > pageBitmap.getHeight()) {
pageBitmap.expand(regionBitmapYLocation + regionBitmapHeight,
pageSegment.getPageInformationFlags().getFlagValue(PageInformationFlags.DEFAULT_PIXEL_VALUE));
}
pageBitmap.combine(bitmap, regionBitmapXLocation, regionBitmapYLocation, extCombOp);
} else {
bitmap.setBitmapNumber(getSegmentHeader().getSegmentNumber());
decoder.appendBitmap(bitmap);
}
if(unknownLength) {
decoder.movePointer(4);
}
}
private void readGenericRegionFlags() throws IOException {
/** extract text region Segment flags */
short genericRegionFlagsField = decoder.readByte();
genericRegionFlags.setFlags(genericRegionFlagsField);
if(JBIG2StreamDecoder.debug)
System.out.println("generic region Segment flags = " + genericRegionFlagsField);
}
public GenericRegionFlags getGenericRegionFlags() {
return genericRegionFlags;
}
}