jbig2stream.cc

来自「source code: Covert TXT to PDF」· CC 代码 · 共 2,563 行 · 第 1/5 页

  // get the Huffman tables
  huffFSTable = huffDSTable = huffDTTable = NULL; // make gcc happy
  huffRDWTable = huffRDHTable = NULL; // make gcc happy
  huffRDXTable = huffRDYTable = huffRSizeTable = NULL; // make gcc happy
  i = 0;
  if (huff) {
    if (huffFS == 0) {
      huffFSTable = huffTableF;
    } else if (huffFS == 1) {
      huffFSTable = huffTableG;
    } else {
      huffFSTable = ((JBIG2CodeTable *)codeTables->get(i++))->getHuffTable();
    }
    if (huffDS == 0) {
      huffDSTable = huffTableH;
    } else if (huffDS == 1) {
      huffDSTable = huffTableI;
    } else if (huffDS == 2) {
      huffDSTable = huffTableJ;
    } else {
      huffDSTable = ((JBIG2CodeTable *)codeTables->get(i++))->getHuffTable();
    }
    if (huffDT == 0) {
      huffDTTable = huffTableK;
    } else if (huffDT == 1) {
      huffDTTable = huffTableL;
    } else if (huffDT == 2) {
      huffDTTable = huffTableM;
    } else {
      huffDTTable = ((JBIG2CodeTable *)codeTables->get(i++))->getHuffTable();
    }
    if (huffRDW == 0) {
      huffRDWTable = huffTableN;
    } else if (huffRDW == 1) {
      huffRDWTable = huffTableO;
    } else {
      huffRDWTable = ((JBIG2CodeTable *)codeTables->get(i++))->getHuffTable();
    }
    if (huffRDH == 0) {
      huffRDHTable = huffTableN;
    } else if (huffRDH == 1) {
      huffRDHTable = huffTableO;
    } else {
      huffRDHTable = ((JBIG2CodeTable *)codeTables->get(i++))->getHuffTable();
    }
    if (huffRDX == 0) {
      huffRDXTable = huffTableN;
    } else if (huffRDX == 1) {
      huffRDXTable = huffTableO;
    } else {
      huffRDXTable = ((JBIG2CodeTable *)codeTables->get(i++))->getHuffTable();
    }
    if (huffRDY == 0) {
      huffRDYTable = huffTableN;
    } else if (huffRDY == 1) {
      huffRDYTable = huffTableO;
    } else {
      huffRDYTable = ((JBIG2CodeTable *)codeTables->get(i++))->getHuffTable();
    }
    if (huffRSize == 0) {
      huffRSizeTable = huffTableA;
    } else {
      huffRSizeTable =
	  ((JBIG2CodeTable *)codeTables->get(i++))->getHuffTable();
    }
  }
  delete codeTables;

  // symbol ID Huffman decoding table
  if (huff) {
    huffDecoder->reset();
    for (i = 0; i < 32; ++i) {
      runLengthTab[i].val = i;
      runLengthTab[i].prefixLen = huffDecoder->readBits(4);
      runLengthTab[i].rangeLen = 0;
    }
    runLengthTab[32].val = 0x103;
    runLengthTab[32].prefixLen = huffDecoder->readBits(4);
    runLengthTab[32].rangeLen = 2;
    runLengthTab[33].val = 0x203;
    runLengthTab[33].prefixLen = huffDecoder->readBits(4);
    runLengthTab[33].rangeLen = 3;
    runLengthTab[34].val = 0x20b;
    runLengthTab[34].prefixLen = huffDecoder->readBits(4);
    runLengthTab[34].rangeLen = 7;
    runLengthTab[35].rangeLen = jbig2HuffmanEOT;
    huffDecoder->buildTable(runLengthTab, 35);
    symCodeTab = (JBIG2HuffmanTable *)gmalloc((numSyms + 1) *
					      sizeof(JBIG2HuffmanTable));
    for (i = 0; i < numSyms; ++i) {
      symCodeTab[i].val = i;
      symCodeTab[i].rangeLen = 0;
    }
    i = 0;
    while (i < numSyms) {
      huffDecoder->decodeInt(&j, runLengthTab);
      if (j > 0x200) {
	for (j -= 0x200; j && i < numSyms; --j) {
	  symCodeTab[i++].prefixLen = 0;
	}
      } else if (j > 0x100) {
	for (j -= 0x100; j && i < numSyms; --j) {
	  symCodeTab[i].prefixLen = symCodeTab[i-1].prefixLen;
	  ++i;
	}
      } else {
	symCodeTab[i++].prefixLen = j;
      }

    }
    symCodeTab[numSyms].rangeLen = jbig2HuffmanEOT;
    huffDecoder->buildTable(symCodeTab, numSyms);
    huffDecoder->reset();

  // set up the arithmetic decoder
  } else {
    symCodeTab = NULL;
    resetIntStats(symCodeLen);
    if (refine) {
      resetRefinementStats(templ, NULL);
    }
    arithDecoder->start();
  }

  bitmap = readTextRegion(huff, refine, w, h, numInstances,
			  logStrips, numSyms, symCodeTab, symCodeLen, syms,
			  defPixel, combOp, transposed, refCorner, sOffset,
			  huffFSTable, huffDSTable, huffDTTable,
			  huffRDWTable, huffRDHTable,
			  huffRDXTable, huffRDYTable, huffRSizeTable,
			  templ, atx, aty);

  gfree(syms);

  // combine the region bitmap into the page bitmap
  if (imm) {
    if (pageH == 0xffffffff && y + h > curPageH) {
      pageBitmap->expand(y + h, pageDefPixel);
    }
    pageBitmap->combine(bitmap, x, y, extCombOp);
    delete bitmap;

  // store the region bitmap
  } else {
    bitmap->setSegNum(segNum);
    segments->append(bitmap);
  }

  // clean up the Huffman decoder
  if (huff) {
    gfree(symCodeTab);
  }

  return;

 eofError:
  error(getPos(), "Unexpected EOF in JBIG2 stream");
}

JBIG2Bitmap *JBIG2Stream::readTextRegion(GBool huff, GBool refine,
					 int w, int h,
					 Guint numInstances,
					 Guint logStrips,
					 int numSyms,
					 JBIG2HuffmanTable *symCodeTab,
					 Guint symCodeLen,
					 JBIG2Bitmap **syms,
					 Guint defPixel, Guint combOp,
					 Guint transposed, Guint refCorner,
					 Guint sOffset,
					 JBIG2HuffmanTable *huffFSTable,
					 JBIG2HuffmanTable *huffDSTable,
					 JBIG2HuffmanTable *huffDTTable,
					 JBIG2HuffmanTable *huffRDWTable,
					 JBIG2HuffmanTable *huffRDHTable,
					 JBIG2HuffmanTable *huffRDXTable,
					 JBIG2HuffmanTable *huffRDYTable,
					 JBIG2HuffmanTable *huffRSizeTable,
					 Guint templ,
					 int *atx, int *aty) {
  JBIG2Bitmap *bitmap;
  JBIG2Bitmap *symbolBitmap;
  Guint strips;
  int t, dt, tt, s, ds, sFirst, j;
  int rdw, rdh, rdx, rdy, ri, refDX, refDY, bmSize;
  Guint symID, inst, bw, bh;

  strips = 1 << logStrips;

  // allocate the bitmap
  bitmap = new JBIG2Bitmap(0, w, h);
  if (defPixel) {
    bitmap->clearToOne();
  } else {
    bitmap->clearToZero();
  }

  // decode initial T value
  if (huff) {
    huffDecoder->decodeInt(&t, huffDTTable);
  } else {
    arithDecoder->decodeInt(&t, iadtStats);
  }
  t *= -strips;

  inst = 0;
  sFirst = 0;
  while (inst < numInstances) {

    // decode delta-T
    if (huff) {
      huffDecoder->decodeInt(&dt, huffDTTable);
    } else {
      arithDecoder->decodeInt(&dt, iadtStats);
    }
    t += dt * strips;

    // first S value
    if (huff) {
      huffDecoder->decodeInt(&ds, huffFSTable);
    } else {
      arithDecoder->decodeInt(&ds, iafsStats);
    }
    sFirst += ds;
    s = sFirst;

    // read the instances
    while (1) {

      // T value
      if (strips == 1) {
	dt = 0;
      } else if (huff) {
	dt = huffDecoder->readBits(logStrips);
      } else {
	arithDecoder->decodeInt(&dt, iaitStats);
      }
      tt = t + dt;

      // symbol ID
      if (huff) {
	if (symCodeTab) {
	  huffDecoder->decodeInt(&j, symCodeTab);
	  symID = (Guint)j;
	} else {
	  symID = huffDecoder->readBits(symCodeLen);
	}
      } else {
	symID = arithDecoder->decodeIAID(symCodeLen, iaidStats);
      }

      // get the symbol bitmap
      symbolBitmap = NULL;
      if (refine) {
	if (huff) {
	  ri = (int)huffDecoder->readBit();
	} else {
	  arithDecoder->decodeInt(&ri, iariStats);
	}
      } else {
	ri = 0;
      }
      if (ri) {
	if (huff) {
	  huffDecoder->decodeInt(&rdw, huffRDWTable);
	  huffDecoder->decodeInt(&rdh, huffRDHTable);
	  huffDecoder->decodeInt(&rdx, huffRDXTable);
	  huffDecoder->decodeInt(&rdy, huffRDYTable);
	  huffDecoder->decodeInt(&bmSize, huffRSizeTable);
	  huffDecoder->reset();
	  arithDecoder->start();
	} else {
	  arithDecoder->decodeInt(&rdw, iardwStats);
	  arithDecoder->decodeInt(&rdh, iardhStats);
	  arithDecoder->decodeInt(&rdx, iardxStats);
	  arithDecoder->decodeInt(&rdy, iardyStats);
	}
	refDX = ((rdw >= 0) ? rdw : rdw - 1) / 2 + rdx;
	refDY = ((rdh >= 0) ? rdh : rdh - 1) / 2 + rdy;

	symbolBitmap =
	  readGenericRefinementRegion(rdw + syms[symID]->getWidth(),
				      rdh + syms[symID]->getHeight(),
				      templ, gFalse, syms[symID],
				      refDX, refDY, atx, aty);
	//~ do we need to use the bmSize value here (in Huffman mode)?
      } else {
	symbolBitmap = syms[symID];
      }

      // combine the symbol bitmap into the region bitmap
      //~ something is wrong here - refCorner shouldn't degenerate into
      //~   two cases
      bw = symbolBitmap->getWidth() - 1;
      bh = symbolBitmap->getHeight() - 1;
      if (transposed) {
	switch (refCorner) {
	case 0: // bottom left
	  bitmap->combine(symbolBitmap, tt, s, combOp);
	  break;
	case 1: // top left
	  bitmap->combine(symbolBitmap, tt, s, combOp);
	  break;
	case 2: // bottom right
	  bitmap->combine(symbolBitmap, tt - bw, s, combOp);
	  break;
	case 3: // top right
	  bitmap->combine(symbolBitmap, tt - bw, s, combOp);
	  break;
	}
	s += bh;
      } else {
	switch (refCorner) {
	case 0: // bottom left
	  bitmap->combine(symbolBitmap, s, tt - bh, combOp);
	  break;
	case 1: // top left
	  bitmap->combine(symbolBitmap, s, tt, combOp);
	  break;
	case 2: // bottom right
	  bitmap->combine(symbolBitmap, s, tt - bh, combOp);
	  break;
	case 3: // top right
	  bitmap->combine(symbolBitmap, s, tt, combOp);
	  break;
	}
	s += bw;
      }
      if (ri) {
	delete symbolBitmap;
      }

      // next instance
      ++inst;

      // next S value
      if (huff) {
	if (!huffDecoder->decodeInt(&ds, huffDSTable)) {
	  break;
	}
      } else {
	if (!arithDecoder->decodeInt(&ds, iadsStats)) {
	  break;
	}
      }
      s += sOffset + ds;
    }
  }

  return bitmap;
}

void JBIG2Stream::readPatternDictSeg(Guint segNum, Guint length) {
  JBIG2PatternDict *patternDict;
  JBIG2Bitmap *bitmap;
  Guint flags, patternW, patternH, grayMax, templ, mmr;
  int atx[4], aty[4];
  Guint i, x;

  // halftone dictionary flags, pattern width and height, max gray value
  if (!readUByte(&flags) ||
      !readUByte(&patternW) ||
      !readUByte(&patternH) ||
      !readULong(&grayMax)) {
    goto eofError;
  }
  templ = (flags >> 1) & 3;
  mmr = flags & 1;

  // set up the arithmetic decoder
  if (!mmr) {
    resetGenericStats(templ, NULL);
    arithDecoder->start();
  }

  // read the bitmap
  atx[0] = -patternW; aty[0] =  0;
  atx[1] = -3;        aty[1] = -1;
  atx[2] =  2;        aty[2] = -2;
  atx[3] = -2;        aty[3] = -2;
  bitmap = readGenericBitmap(mmr, (grayMax + 1) * patternW, patternH,
			     templ, gFalse, gFalse, NULL,
			     atx, aty, length - 7);

  // create the pattern dict object
  patternDict = new JBIG2PatternDict(segNum, grayMax + 1);

  // split up the bitmap
  x = 0;
  for (i = 0; i <= grayMax; ++i) {
    patternDict->setBitmap(i, bitmap->getSlice(x, 0, patternW, patternH));
    x += patternW;
  }

  // free memory
  delete bitmap;

  // store the new pattern dict
  segments->append(patternDict);

  return;

 eofError:
  error(getPos(), "Unexpected EOF in JBIG2 stream");
}

void JBIG2Stream::readHalftoneRegionSeg(Guint segNum, GBool imm,
					GBool lossless, Guint length,
					Guint *refSegs, Guint nRefSegs) {
  JBIG2Bitmap *bitmap;
  JBIG2Segment *seg;
  JBIG2PatternDict *patternDict;
  JBIG2Bitmap *skipBitmap;
  Guint *grayImg;
  JBIG2Bitmap *grayBitmap;
  JBIG2Bitmap *patternBitmap;
  Guint w, h, x, y, segInfoFlags, extCombOp;
  Guint flags, mmr, templ, enableSkip, combOp;
  Guint gridW, gridH, stepX, stepY, patW, patH;
  int atx[4], aty[4];
  int gridX, gridY, xx, yy, bit, j;
  Guint bpp, m, n, i;

  // region segment info field
  if (!readULong(&w) || !readULong(&h) ||
      !readULong(&x) || !readULong(&y) ||
      !readUByte(&segInfoFlags)) {
    goto eofError;
  }
  extCombOp = segInfoFlags & 7;

  // rest of the halftone region header
  if (!readUByte(&flags)) {
    goto eofError;
  }
  mmr = flags & 1;
  templ = (flags >> 1) & 3;
  enableSkip = (flags >> 3) & 1;
  combOp = (flags >> 4) & 7;
  if (!readULong(&gridW) || !readULong(&gridH) ||
      !readLong(&gridX) || !readLong(&gridY) ||
      !readUWord(&stepX) || !readUWord(&stepY)) {
    goto eofError;
  }

  // get pattern dictionary
  if (nRefSegs != 1) {
    error(getPos(), "Bad symbol dictionary reference in JBIG2 halftone segment");
    return;
  }
  seg = findSegment(refSegs[0]);
  if (seg->getType() != jbig2SegPatternDict) {
    error(getPos(), "Bad symbol dictionary reference in JBIG2 halftone segment");
    return;
  }
  patternDict = (JBIG2PatternDict *)seg;
  bpp = 0;
  i = 1;
  while (i < patternDict->getSize()) {
    ++bpp;
    i <<= 1;
  }
  patW = patternDict->getBitmap(0)->getWidth();
  patH = patternDict->getBitmap(0)->getHeight();

  // set up the arithmetic decoder
  if (!mmr) {
    resetGenericStats(templ, NULL);
    arithDecoder->start();
  }

  // allocate the bitmap
  bitmap = new JBIG2Bitmap(segNum, w, h);
  if (flags & 0x80) { // HDEFPIXEL
    bitmap->clearToOne();
  } else {
    bitmap->clearToZero();
  }

  // compute the skip bitmap
  skipBitmap = NULL;
  if (enableSkip) {
    skipBitmap = new JBIG2Bitmap(0, gridW, gridH);
    skipBitmap->clearToZero();
    for (m = 0; m < gridH; ++m) {
      xx = gridX + m * stepY;
      yy = gridY + m * stepX;
      for (n = 0; n < gridW; ++n) {
	if (((xx + (int)patW) >> 8) <= 0 || (xx >> 8) >= (int)w ||
	    ((yy + (int)patH) >> 8) <= 0 || (yy >> 8) >= (int)h) {
	  skipBitmap->setPixel(n, m);
	}
      }
    }
  }

  // read the gray-scale image
  grayImg = (Guint *)gmalloc(gridW * gridH * sizeof(Guint));
  memset(grayImg, 0, gridW * gridH * sizeof(Guint));
  atx[0] = templ <= 1 ? 3 : 2;  aty[0] = -1;
  atx[1] = -3;                  aty[1] = -1;
  atx[2] =  2;                  aty[2] = -2;
  atx[3] = -2;                  aty[3] = -2;
  for (j = bpp - 1; j >= 0; --j) {
    grayBitmap = readGenericBitmap(mmr, gridW, gridH, templ, gFalse,
				   enableSkip, skipBitmap, atx, aty, -1);
    i = 0;
    for (m = 0; m < gridH; ++m) {
      for (n = 0; n < gridW; ++n) {
	bit = grayBitmap->getPixel(n, m) ^ (grayImg[i] & 1);