/**
* ===========================================
* 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.
*
* ---------------
* HalftoneRegionSegment.java
* ---------------
*/
package org.jpedal.jbig2.segment.region.halftone;
import org.jpedal.jbig2.JBIG2Exception;
import org.jpedal.jbig2.decoders.JBIG2StreamDecoder;
import org.jpedal.jbig2.image.JBIG2Bitmap;
import org.jpedal.jbig2.segment.Segment;
import org.jpedal.jbig2.segment.pageinformation.PageInformationSegment;
import org.jpedal.jbig2.segment.pattern.PatternDictionarySegment;
import org.jpedal.jbig2.segment.region.RegionFlags;
import org.jpedal.jbig2.segment.region.RegionSegment;
import org.jpedal.jbig2.util.BinaryOperation;
import java.io.IOException;
public class HalftoneRegionSegment extends RegionSegment {
private HalftoneRegionFlags halftoneRegionFlags = new HalftoneRegionFlags();
private boolean inlineImage;
public HalftoneRegionSegment(JBIG2StreamDecoder streamDecoder, boolean inlineImage) {
super(streamDecoder);
this.inlineImage = inlineImage;
}
public void readSegment() throws IOException, JBIG2Exception {
super.readSegment();
/** read text region Segment flags */
readHalftoneRegionFlags();
short[] buf = new short[4];
decoder.readByte(buf);
int gridWidth = BinaryOperation.getInt32(buf);
buf = new short[4];
decoder.readByte(buf);
int gridHeight = BinaryOperation.getInt32(buf);
buf = new short[4];
decoder.readByte(buf);
int gridX = BinaryOperation.getInt32(buf);
buf = new short[4];
decoder.readByte(buf);
int gridY = BinaryOperation.getInt32(buf);
if (JBIG2StreamDecoder.debug)
System.out.println("grid pos and size = " + gridX + ',' + gridY + ' ' + gridWidth + ',' + gridHeight);
buf = new short[2];
decoder.readByte(buf);
int stepX = BinaryOperation.getInt16(buf);
buf = new short[2];
decoder.readByte(buf);
int stepY = BinaryOperation.getInt16(buf);
if (JBIG2StreamDecoder.debug)
System.out.println("step size = " + stepX + ',' + stepY);
int[] referedToSegments = segmentHeader.getReferredToSegments();
if (referedToSegments.length != 1) {
System.out.println("Error in halftone Segment. refSegs should == 1");
}
Segment segment = decoder.findSegment(referedToSegments[0]);
if (segment.getSegmentHeader().getSegmentType() != Segment.PATTERN_DICTIONARY) {
if(JBIG2StreamDecoder.debug)
System.out.println("Error in halftone Segment. bad symbol dictionary reference");
}
PatternDictionarySegment patternDictionarySegment = (PatternDictionarySegment) segment;
int bitsPerValue = 0, i = 1;
while (i < patternDictionarySegment.getSize()) {
bitsPerValue++;
i <<= 1;
}
JBIG2Bitmap bitmap = patternDictionarySegment.getBitmaps()[0];
int patternWidth = bitmap.getWidth();
int patternHeight = bitmap.getHeight();
if (JBIG2StreamDecoder.debug)
System.out.println("pattern size = " + patternWidth + ',' + patternHeight);
boolean useMMR = halftoneRegionFlags.getFlagValue(HalftoneRegionFlags.H_MMR) != 0;
int template = halftoneRegionFlags.getFlagValue(HalftoneRegionFlags.H_TEMPLATE);
if (!useMMR) {
arithmeticDecoder.resetGenericStats(template, null);
arithmeticDecoder.start();
}
int halftoneDefaultPixel = halftoneRegionFlags.getFlagValue(HalftoneRegionFlags.H_DEF_PIXEL);
bitmap = new JBIG2Bitmap(regionBitmapWidth, regionBitmapHeight, arithmeticDecoder, huffmanDecoder, mmrDecoder);
bitmap.clear(halftoneDefaultPixel);
boolean enableSkip = halftoneRegionFlags.getFlagValue(HalftoneRegionFlags.H_ENABLE_SKIP) != 0;
JBIG2Bitmap skipBitmap = null;
if (enableSkip) {
skipBitmap = new JBIG2Bitmap(gridWidth, gridHeight, arithmeticDecoder, huffmanDecoder, mmrDecoder);
skipBitmap.clear(0);
for (int y = 0; y < gridHeight; y++) {
for (int x = 0; x < gridWidth; x++) {
int xx = gridX + y * stepY + x * stepX;
int yy = gridY + y * stepX - x * stepY;
if (((xx + patternWidth) >> 8) <= 0 || (xx >> 8) >= regionBitmapWidth || ((yy + patternHeight) >> 8) <= 0 || (yy >> 8) >= regionBitmapHeight) {
skipBitmap.setPixel(y, x, 1);
}
}
}
}
int[] grayScaleImage = new int[gridWidth * gridHeight];
short[] genericBAdaptiveTemplateX = new short[4], genericBAdaptiveTemplateY = new short[4];
genericBAdaptiveTemplateX[0] = (short) (template <= 1 ? 3 : 2);
genericBAdaptiveTemplateY[0] = -1;
genericBAdaptiveTemplateX[1] = -3;
genericBAdaptiveTemplateY[1] = -1;
genericBAdaptiveTemplateX[2] = 2;
genericBAdaptiveTemplateY[2] = -2;
genericBAdaptiveTemplateX[3] = -2;
genericBAdaptiveTemplateY[3] = -2;
JBIG2Bitmap grayBitmap ;
for (int j = bitsPerValue - 1; j >= 0; --j) {
grayBitmap = new JBIG2Bitmap(gridWidth, gridHeight, arithmeticDecoder, huffmanDecoder, mmrDecoder);
grayBitmap.readBitmap(useMMR, template, false, enableSkip, skipBitmap, genericBAdaptiveTemplateX, genericBAdaptiveTemplateY, -1);
i = 0;
for (int row = 0; row < gridHeight; row++) {
for (int col = 0; col < gridWidth; col++) {
int bit = grayBitmap.getPixel(col, row) ^ (grayScaleImage[i] & 1);
grayScaleImage[i] = (grayScaleImage[i] << 1) | bit;
i++;
}
}
}
int combinationOperator = halftoneRegionFlags.getFlagValue(HalftoneRegionFlags.H_COMB_OP);
i = 0;
for (int col = 0; col < gridHeight; col++) {
int xx = gridX + col * stepY;
int yy = gridY + col * stepX;
for (int row = 0; row < gridWidth; row++) {
if (!(enableSkip && skipBitmap.getPixel(col, row) == 1)) {
JBIG2Bitmap patternBitmap = patternDictionarySegment.getBitmaps()[grayScaleImage[i]];
bitmap.combine(patternBitmap, xx >> 8, yy >> 8, combinationOperator);
}
xx += stepX;
yy -= stepY;
i++;
}
}
if (inlineImage) {
PageInformationSegment pageSegment = decoder.findPageSegement(segmentHeader.getPageAssociation());
JBIG2Bitmap pageBitmap = pageSegment.getPageBitmap();
int externalCombinationOperator = regionFlags.getFlagValue(RegionFlags.EXTERNAL_COMBINATION_OPERATOR);
pageBitmap.combine(bitmap, regionBitmapXLocation, regionBitmapYLocation, externalCombinationOperator);
} else {
bitmap.setBitmapNumber(getSegmentHeader().getSegmentNumber());
decoder.appendBitmap(bitmap);
}
}
private void readHalftoneRegionFlags() throws IOException {
/** extract text region Segment flags */
short halftoneRegionFlagsField = decoder.readByte();
halftoneRegionFlags.setFlags(halftoneRegionFlagsField);
if (JBIG2StreamDecoder.debug)
System.out.println("generic region Segment flags = " + halftoneRegionFlagsField);
}
public HalftoneRegionFlags getHalftoneRegionFlags() {
return halftoneRegionFlags;
}
}