private void ReadSegments()
{
bool finished = false;
while (!reader.IsFinished() && !finished)
{
SegmentHeader segmentHeader = new SegmentHeader();
ReadSegmentHeader(segmentHeader);
// read the Segment data
Segment segment = null;
int segmentType = segmentHeader.GetSegmentType();
int[] referredToSegments = segmentHeader.GetReferredToSegments();
int noOfReferredToSegments = segmentHeader.GetReferredToSegmentCount();
switch (segmentType)
{
case Segment.SYMBOL_DICTIONARY:
segment = new SymbolDictionarySegment(this);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.INTERMEDIATE_TEXT_REGION:
segment = new TextRegionSegment(this, false);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.IMMEDIATE_TEXT_REGION:
segment = new TextRegionSegment(this, true);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.IMMEDIATE_LOSSLESS_TEXT_REGION:
segment = new TextRegionSegment(this, true);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.PATTERN_DICTIONARY:
segment = new PatternDictionarySegment(this);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.INTERMEDIATE_HALFTONE_REGION:
segment = new HalftoneRegionSegment(this, false);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.IMMEDIATE_HALFTONE_REGION:
segment = new HalftoneRegionSegment(this, true);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.IMMEDIATE_LOSSLESS_HALFTONE_REGION:
segment = new HalftoneRegionSegment(this, true);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.INTERMEDIATE_GENERIC_REGION:
segment = new GenericRegionSegment(this, false);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.IMMEDIATE_GENERIC_REGION:
segment = new GenericRegionSegment(this, true);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.IMMEDIATE_LOSSLESS_GENERIC_REGION:
segment = new GenericRegionSegment(this, true);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.INTERMEDIATE_GENERIC_REFINEMENT_REGION:
segment = new RefinementRegionSegment(this, false, referredToSegments, noOfReferredToSegments);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.IMMEDIATE_GENERIC_REFINEMENT_REGION:
segment = new RefinementRegionSegment(this, true, referredToSegments, noOfReferredToSegments);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.IMMEDIATE_LOSSLESS_GENERIC_REFINEMENT_REGION:
segment = new RefinementRegionSegment(this, true, referredToSegments, noOfReferredToSegments);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.PAGE_INFORMATION:
segment = new PageInformationSegment(this);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.END_OF_PAGE:
continue;
case Segment.END_OF_STRIPE:
segment = new EndOfStripeSegment(this);
segment.SetSegmentHeader(segmentHeader);
break;
case Segment.END_OF_FILE:
finished = true;
continue;
case Segment.PROFILES:
break;
case Segment.TABLES:
break;
case Segment.EXTENSION:
segment = new ExtensionSegment(this);
segment.SetSegmentHeader(segmentHeader);
break;
default:
break;
}
if (!randomAccessOrganisation)
{
segment.ReadSegment();
}
segments.Add(segment);
}
if (randomAccessOrganisation)
{
foreach (Segment segment in segments)
{
segment.ReadSegment();
}
}
}
public override void ReadSegment()
{
base.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)
{
Console.WriteLine("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)
{
Console.WriteLine("step size = " + stepX + ',' + stepY);
}
int[] referedToSegments = segmentHeader.GetReferredToSegments();
if (referedToSegments.Length != 1)
{
Console.WriteLine("Error in halftone Segment. refSegs should == 1");
}
Segment segment = decoder.FindSegment(referedToSegments[0]);
if (segment.GetSegmentHeader().GetSegmentType() != Segment.PATTERN_DICTIONARY)
{
if (JBIG2StreamDecoder.debug)
{
Console.WriteLine("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];
long patternWidth = bitmap.GetWidth();
long patternHeight = bitmap.GetHeight();
if (JBIG2StreamDecoder.debug)
{
Console.WriteLine("pattern size = " + patternWidth + ',' + patternHeight);
}
bool 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);
bool 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);
}
}