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/**
 * ===========================================
 * 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; } }





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