public void ReadSegment() { if (JBIG2StreamDecoder.debug) { Console.WriteLine("==== Reading Generic Refinement Region ===="); } base.ReadSegment(); /** read text region segment flags */ ReadGenericRegionFlags(); short[] genericRegionAdaptiveTemplateX = new short[2]; short[] genericRegionAdaptiveTemplateY = new short[2]; int template = refinementRegionFlags.GetFlagValue(RefinementRegionFlags.GR_TEMPLATE); if (template == 0) { genericRegionAdaptiveTemplateX[0] = ReadATValue(); genericRegionAdaptiveTemplateY[0] = ReadATValue(); genericRegionAdaptiveTemplateX[1] = ReadATValue(); genericRegionAdaptiveTemplateY[1] = ReadATValue(); } if (noOfReferedToSegments == 0 || inlineImage) { PageInformationSegment pageSegment = decoder.FindPageSegement(segmentHeader.GetPageAssociation()); JBIG2Bitmap pageBitmap = pageSegment.GetPageBitmap(); if (pageSegment.GetPageBitmapHeight() == -1 && regionBitmapYLocation + regionBitmapHeight > pageBitmap.GetHeight()) { pageBitmap.Expand(regionBitmapYLocation + regionBitmapHeight, pageSegment.GetPageInformationFlags().GetFlagValue(PageInformationFlags.DEFAULT_PIXEL_VALUE)); } } if (noOfReferedToSegments > 1) { if (JBIG2StreamDecoder.debug) { Console.WriteLine("Bad reference in JBIG2 generic refinement Segment"); } return; } JBIG2Bitmap referedToBitmap; if (noOfReferedToSegments == 1) { referedToBitmap = decoder.FindBitmap(referedToSegments[0]); } else { PageInformationSegment pageSegment = decoder.FindPageSegement(segmentHeader.GetPageAssociation()); JBIG2Bitmap pageBitmap = pageSegment.GetPageBitmap(); referedToBitmap = pageBitmap.GetSlice(regionBitmapXLocation, regionBitmapYLocation, regionBitmapWidth, regionBitmapHeight); } arithmeticDecoder.ResetRefinementStats(template, null); arithmeticDecoder.Start(); bool typicalPredictionGenericRefinementOn = refinementRegionFlags.GetFlagValue(RefinementRegionFlags.TPGDON) != 0; JBIG2Bitmap bitmap = new JBIG2Bitmap(regionBitmapWidth, regionBitmapHeight, arithmeticDecoder, huffmanDecoder, mmrDecoder); bitmap.ReadGenericRefinementRegion(template, typicalPredictionGenericRefinementOn, referedToBitmap, 0, 0, genericRegionAdaptiveTemplateX, genericRegionAdaptiveTemplateY); if (inlineImage) { PageInformationSegment pageSegment = decoder.FindPageSegement(segmentHeader.GetPageAssociation()); JBIG2Bitmap pageBitmap = pageSegment.GetPageBitmap(); int extCombOp = regionFlags.GetFlagValue(RegionFlags.EXTERNAL_COMBINATION_OPERATOR); pageBitmap.Combine(bitmap, regionBitmapXLocation, regionBitmapYLocation, extCombOp); } else { bitmap.SetBitmapNumber(GetSegmentHeader().GetSegmentNumber()); decoder.AppendBitmap(bitmap); } }
public override void ReadSegment() { if (JBIG2StreamDecoder.debug) { Console.WriteLine("==== Reading Immediate Generic Region ===="); } base.ReadSegment(); /** read text region Segment flags */ ReadGenericRegionFlags(); bool 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(); } bool 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); } }