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cjb2.cpp

//C-  -*- C++ -*-
//C- -------------------------------------------------------------------
//C- DjVuLibre-3.5
//C- Copyright (c) 2002  Leon Bottou and Yann Le Cun.
//C- Copyright (c) 2001  AT&T
//C-
//C- This software is subject to, and may be distributed under, the
//C- GNU General Public License, either Version 2 of the license,
//C- or (at your option) any later version. The license should have
//C- accompanied the software or you may obtain a copy of the license
//C- from the Free Software Foundation at http://www.fsf.org .
//C-
//C- This program is distributed in the hope that it will be useful,
//C- but WITHOUT ANY WARRANTY; without even the implied warranty of
//C- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//C- GNU General Public License for more details.
//C- 
//C- DjVuLibre-3.5 is derived from the DjVu(r) Reference Library from
//C- Lizardtech Software.  Lizardtech Software has authorized us to
//C- replace the original DjVu(r) Reference Library notice by the following
//C- text (see doc/lizard2002.djvu and doc/lizardtech2007.djvu):
//C-
//C-  ------------------------------------------------------------------
//C- | DjVu (r) Reference Library (v. 3.5)
//C- | Copyright (c) 1999-2001 LizardTech, Inc. All Rights Reserved.
//C- | The DjVu Reference Library is protected by U.S. Pat. No.
//C- | 6,058,214 and patents pending.
//C- |
//C- | This software is subject to, and may be distributed under, the
//C- | GNU General Public License, either Version 2 of the license,
//C- | or (at your option) any later version. The license should have
//C- | accompanied the software or you may obtain a copy of the license
//C- | from the Free Software Foundation at http://www.fsf.org .
//C- |
//C- | The computer code originally released by LizardTech under this
//C- | license and unmodified by other parties is deemed "the LIZARDTECH
//C- | ORIGINAL CODE."  Subject to any third party intellectual property
//C- | claims, LizardTech grants recipient a worldwide, royalty-free, 
//C- | non-exclusive license to make, use, sell, or otherwise dispose of 
//C- | the LIZARDTECH ORIGINAL CODE or of programs derived from the 
//C- | LIZARDTECH ORIGINAL CODE in compliance with the terms of the GNU 
//C- | General Public License.   This grant only confers the right to 
//C- | infringe patent claims underlying the LIZARDTECH ORIGINAL CODE to 
//C- | the extent such infringement is reasonably necessary to enable 
//C- | recipient to make, have made, practice, sell, or otherwise dispose 
//C- | of the LIZARDTECH ORIGINAL CODE (or portions thereof) and not to 
//C- | any greater extent that may be necessary to utilize further 
//C- | modifications or combinations.
//C- |
//C- | The LIZARDTECH ORIGINAL CODE is provided "AS IS" WITHOUT WARRANTY
//C- | OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
//C- | TO ANY WARRANTY OF NON-INFRINGEMENT, OR ANY IMPLIED WARRANTY OF
//C- | MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
//C- +------------------------------------------------------------------
// 
// $Id: cjb2.cpp,v 1.18 2007/05/19 03:07:34 leonb Exp $
// $Name: debian_version_3_5_20-7 $

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#if NEED_GNUG_PRAGMAS
# pragma implementation
#endif

/** @name cjb2

    {\bf Synopsis}
    \begin{verbatim}
        cjb2 [options] <input-pbm-or-tiff>  <output-djvu>
    \end{verbatim}

    {\bf Description}

    File #"cjb2.cpp"# demonstrates a simple encoder for Bilevel DjVu Images.
    It is able to perform lossless encoding and limited lossy encoding.  Lots
    of lossy encoding refinements are missing from this simple implementation.
    Comments in the code suggest a few improvements.

    Options are:
    \begin{description}
    \item[-dpi xxx]     Specify image resolution (default 300).
    \item[-lossless]    Lossless compresion (same as -losslevel 0, default).
    \item[-clean]       Quasi-lossless compresion (same as -losslevel 1).
    \item[-lossy]       Lossy compression (same as -losslevel 100).
    \item[-losslevel n] Set loss level (0 to 200)
    \item[-verbose]     Displays additional messages.
    \end{description}
    Encoding is lossless unless one or several lossy options are selected.
    The #dpi# argument mostly affects the cleaning thresholds.

    {\bf Bugs}

    This is not the full-fledged multipage DjVu compressor, but merely a free
    tool provided with the DjVu Reference Library as a demonstrative example.

    @memo
    Simple JB2 encoder.
    @author
    L\'eon Bottou <leonb@research.att.com>\\
    Paul Howard <pgh@research.att.com>\\
    Pascal Vincent <vincentp@iro.umontreal.ca>\\
    Ilya Mezhirov <ilya@mezhirov.mccme.ru>
    @version
    $Id: cjb2.cpp,v 1.18 2007/05/19 03:07:34 leonb Exp $ */
//@{
//@}


#include "DjVuGlobal.h"
#include "GException.h"
#include "GSmartPointer.h"
#include "GContainer.h"
#include "ByteStream.h"
#include "IFFByteStream.h"
#include "GRect.h"
#include "GBitmap.h"
#include "JB2Image.h"
#include "DjVuInfo.h"
#include "GOS.h"
#include "GURL.h"
#include "DjVuMessage.h"

#include "jb2tune.h"

#include <locale.h>
#include <stdlib.h>
#if HAVE_TIFF
#include <tiffio.h>
#endif

// --------------------------------------------------
// UTILITIES
// --------------------------------------------------

#ifdef MIN
#undef MIN
#endif

inline int 
MIN(int a, int b) 
{ 
  return ( a<b ?a :b); 
}

#ifdef MAX
#undef MAX
#endif

inline int 
MAX(int a, int b) 
{ 
  return ( a>b ?a :b); 
}






// --------------------------------------------------
// CONNECTED COMPONENT ANALYSIS AND CLEANING
// --------------------------------------------------

// -- A run of black pixels
struct Run    
{ 
  int y;         // vertical coordinate
  short x1;      // first horizontal coordinate
  short x2;      // last horizontal coordinate
  int ccid;      // component id
};

// -- A component descriptor
struct CC    
{
  GRect bb;      // bounding box
  int npix;      // number of black pixels
  int nrun;      // number of runs
  int frun;      // first run in cc ordered array of runs
};


// -- An image composed of runs
class CCImage 
{
public:
  int height;            // Height of the image in pixels
  int width;             // Width of the image in pixels
  GTArray<Run> runs;     // array of runs
  GTArray<CC>  ccs;      // Array of component descriptors
  int nregularccs;       // Number of regular ccs (set by merge_and_split_ccs)
  int largesize;         // CCs larger than that are special
  int smallsize;         // CCs smaller than that are special 
  int tinysize;          // CCs smaller than that may be removed 
  CCImage();
  void init(int width, int height, int dpi);
  void add_single_run(int y, int x1, int x2, int ccid=0);
  void add_bitmap_runs(const GBitmap &bm, int offx=0, int offy=0, int ccid=0);
  GP<GBitmap> get_bitmap_for_cc(int ccid) const;
  GP<JB2Image> get_jb2image() const;
  void make_ccids_by_analysis();
  void make_ccs_from_ccids();
  void erase_tiny_ccs();
  void merge_and_split_ccs();
  void sort_in_reading_order(); 
};


// -- Compares runs
static inline bool
operator <= (const Run &a, const Run &b)
{
  return (a.y<b.y) || (a.y==b.y && a.x1<=b.x1);
}


// -- Constructs CCImage and provide defaults
CCImage::CCImage()
  : height(0), width(0), nregularccs(0)
{
}

void
CCImage::init(int w, int h, int dpi)
{
  runs.empty();
  ccs.empty();
  height = h;
  width = w;
  nregularccs = 0;
  dpi = MAX(200, MIN(900, dpi));
  largesize = MIN( 500, MAX(64, dpi));
  smallsize = MAX(2, dpi/150);
  tinysize = MAX(0, dpi*dpi/20000 - 1);
}


// -- Adds a run to the CCImage
inline void 
CCImage::add_single_run(int y, int x1, int x2, int ccid)
{
  int index = runs.hbound();
  runs.touch(++index);
  Run& run = runs[index];
  run.y = y;
  run.x1 = x1;
  run.x2 = x2;
  run.ccid = ccid;
}


// -- Adds runs extracted from a bitmap
void 
CCImage::add_bitmap_runs(const GBitmap &bm, int offx, int offy, int ccid)
{
  // Iterate over rows
  for (unsigned int y=0; y<bm.rows(); y++)
    {
      const unsigned char *row = bm[y];
      int w = bm.columns();
      int x = 0;
      // Iterate over runs
      while (x < w)
        {
          while (x < w  && !row[x]) x++;
          if (x < w)
            {
              int x1 = x;
              while (x < w && row[x]) x++;
              add_single_run(offy+y, offx+x1, offx+x-1, ccid);
            }
        }
    }
}


// -- Performs connected component analysis
void
CCImage::make_ccids_by_analysis()
{
  // Sort runs
  runs.sort();
  // Single Pass Connected Component Analysis (with unodes)
  int n;
  int p=0;
  GTArray<int> umap;
  for (n=0; n<=runs.hbound(); n++)
    {
      int y = runs[n].y;
      int x1 = runs[n].x1 - 1;
      int x2 = runs[n].x2 + 1;
      int id = (umap.hbound() + 1);
      // iterate over previous line runs
      for(;runs[p].y < y-1;p++);
      for(;(runs[p].y < y) && (runs[p].x1 <= x2);p++ )
        {
          if ( runs[p].x2 >= x1 )
            {
              // previous run touches current run
              int oid = runs[p].ccid;
              while (umap[oid] < oid)
                oid = umap[oid];
              if ((int)id > umap.hbound()) {
                id = oid;
              } else if (id < oid) {
                umap[oid] = id;
              } else {
                umap[id] = oid;
                id = oid;
              }
              // freshen previous run id
              runs[p].ccid = id;
              // stop if previous run goes past current run
              if (runs[p].x2 >= x2)
                break;
            }
        }
      // create new entry in umap
      runs[n].ccid = id;
      if (id > umap.hbound())
        {
          umap.touch(id);
          umap[id] = id;
        }
    }
  // Update umap and ccid
  for (n=0; n<=runs.hbound(); n++)
    {
      Run &run = runs[n];
      int ccid = run.ccid;
      while (umap[ccid] < ccid)
      {
        ccid = umap[ccid];
      }
      umap[run.ccid] = ccid;
      run.ccid = ccid;
    }
}


// -- Constructs the ``ccs'' array from run's ccids.
void
CCImage::make_ccs_from_ccids()
{
  int n;
  Run *pruns = runs;
  // Find maximal ccid
  int maxccid = nregularccs-1;
  for (n=0; n<=runs.hbound(); n++)
    if (pruns[n].ccid > maxccid)
      maxccid = runs[n].ccid;
  // Renumber ccs 
  GTArray<int> armap(0,maxccid);
  int *rmap = armap;
  for (n=0; n<=maxccid; n++)
    armap[n] = -1;
  for (n=0; n<=runs.hbound(); n++)
    if (pruns[n].ccid >= 0)
      rmap[ pruns[n].ccid ] = 1;
  int nid = 0;
  for (n=0; n<=maxccid; n++)
    if (rmap[n] > 0)
      rmap[n] = nid++;
  
  // Adjust nregularccs (since ccs are renumbered)
  while (nregularccs>0 && rmap[nregularccs-1]<0)
    nregularccs -= 1;
  if (nregularccs>0)
    nregularccs = 1 + rmap[nregularccs-1];
  
  // Prepare cc descriptors
  ccs.resize(0,nid-1);
  for (n=0; n<nid; n++)
    ccs[n].nrun = 0;
  
  // Relabel runs
  for (n=0; n<=runs.hbound(); n++)
    {
      Run &run = pruns[n];
      if (run.ccid < 0) continue;  // runs with negative ccids are destroyed
      int oldccid = run.ccid;
      int newccid = rmap[oldccid];
      CC &cc = ccs[newccid];
      run.ccid = newccid;
      cc.nrun += 1;
    }
  
  // Compute positions for runs of cc
  int frun = 0;
  for (n=0; n<nid; n++) 
    {
      ccs[n].frun = rmap[n] = frun;
      frun += ccs[n].nrun;
    }

  // Copy runs
  GTArray<Run> rtmp;
  rtmp.steal(runs);
  Run *ptmp = rtmp;
  runs.resize(0,frun-1);
  pruns = runs;
  for (n=0; n<=rtmp.hbound(); n++)
    {
      int id = ptmp[n].ccid;
      if (id < 0) continue;
      int pos = rmap[id]++;
      pruns[pos] = ptmp[n];
    }

  // Finalize ccs
  for (n=0; n<nid; n++)
    {
      CC &cc = ccs[n];
      int npix = 0;
      runs.sort(cc.frun, cc.frun+cc.nrun-1);
      Run *run = &runs[cc.frun];
      int xmin = run->x1;
      int xmax = run->x2;
      int ymin = run->y;
      int ymax = run->y;
      for (int i=0; i<cc.nrun; i++, run++)
        {
          if (run->x1 < xmin)  xmin = run->x1;
          if (run->x2 > xmax)  xmax = run->x2;
          if (run->y  < ymin)  ymin = run->y;
          if (run->y  > ymax)  ymax = run->y;
          npix += run->x2 - run->x1 + 1;
        }
      cc.npix = npix;
      cc.bb.xmin = xmin;
      cc.bb.ymin = ymin;
      cc.bb.xmax = xmax + 1;
      cc.bb.ymax = ymax + 1;
    }
}


// Removes ccs which are too small.
void
CCImage::erase_tiny_ccs()
{
  // ISSUE: HALFTONE DETECTION
  // We should not remove tiny ccs if they are part of a halftone pattern...
  for (int i=0; i<ccs.size(); i++)
    {
      CC& cc = ccs[i];
      if (cc.npix <= tinysize)
        {
          // Mark cc to be erased
          Run *r = &runs[cc.frun];
          int nr = cc.nrun;
          cc.nrun = 0;
          cc.npix = 0;
          while (--nr >= 0)
            (r++)->ccid = -1;
        }
    }
}
 

// -- Merges small ccs and split large ccs
void
CCImage::merge_and_split_ccs()
{
  int ncc = ccs.size();
  int nruns = runs.size();
  int splitsize = largesize;
  if (ncc <= 0) return;
  // Grid of special components
  int gridwidth = (width+splitsize-1)/splitsize;
  nregularccs = ncc;
  // Set the correct ccids for the runs
  for (int ccid=0; ccid<ncc; ccid++)
    {
      CC* cc = &ccs[ccid];
      if (cc->nrun <= 0) continue;
      int ccheight = cc->bb.height();
      int ccwidth = cc->bb.width();
      if (ccheight<=smallsize && ccwidth<=smallsize)
        {
          int gridi = (cc->bb.ymin+cc->bb.ymax)/splitsize/2;
          int gridj = (cc->bb.xmin+cc->bb.xmax)/splitsize/2;
          int newccid = ncc + gridi*gridwidth + gridj;
          for(int runid=cc->frun; runid<cc->frun+cc->nrun; runid++)
            runs[runid].ccid = newccid;
        }
      else if (ccheight>=largesize || ccwidth>=largesize)
        {
          for(int runid=cc->frun; runid<cc->frun+cc->nrun; runid++)
            {
              Run& r = runs[runid];
              int y = r.y;
              int x_start = r.x1;
              int x_end = r.x2;
              int gridi = y/splitsize;
              int gridj_start = x_start/splitsize;
              int gridj_end = x_end/splitsize;
              int gridj_span = gridj_end-gridj_start;
              int newccid = ncc + gridi*gridwidth + gridj_start;
              if (! gridj_span)
                {
                  r.ccid = newccid;
                }
              else // gridj_span>0
                {
                  // truncate the current run 
                  r.ccid = newccid++;
                  int x = (gridj_start+1)*splitsize;
                  r.x2 = x-1;
                  runs.touch(nruns+gridj_span-1);
                  // append additional runs to the runs array
                  for(int gridj=gridj_start+1; gridj<gridj_end; gridj++)
                    {
                      Run& newrun = runs[nruns++];
                      newrun.y = y;
                      newrun.x1 = x;
                      x += splitsize;
                      newrun.x2 = x-1;
                      newrun.ccid = newccid++;
                    }
                  // append last run to the run array
                  Run& newrun = runs[nruns++];
                  newrun.y = y;
                  newrun.x1 = x;
                  newrun.x2 = x_end;
                  newrun.ccid = newccid++;                      
                }
            }
        }
    }
  // Recompute cc descriptors
  make_ccs_from_ccids();
}


// -- Helps sorting cc
static int 
top_edges_descending (const void *pa, const void *pb)
{
  if (((CC*) pa)->bb.ymax != ((CC*) pb)->bb.ymax)
    return (((CC*) pb)->bb.ymax - ((CC*) pa)->bb.ymax);
  if (((CC*) pa)->bb.xmin != ((CC*) pb)->bb.xmin)
    return (((CC*) pa)->bb.xmin - ((CC*) pb)->bb.xmin);
  return (((CC*) pa)->frun - ((CC*) pb)->frun);
}


// -- Helps sorting cc
static int 
left_edges_ascending (const void *pa, const void *pb)
{
  if (((CC*) pa)->bb.xmin != ((CC*) pb)->bb.xmin)
    return (((CC*) pa)->bb.xmin - ((CC*) pb)->bb.xmin);
  if (((CC*) pb)->bb.ymax != ((CC*) pa)->bb.ymax)
    return (((CC*) pb)->bb.ymax - ((CC*) pa)->bb.ymax);
  return (((CC*) pa)->frun - ((CC*) pb)->frun);
}


// -- Helps sorting cc
static int 
integer_ascending (const void *pa, const void *pb)
{
  return ( *(int*)pb - *(int*)pa );
}


// -- Sort ccs in approximate reading order
void 
CCImage::sort_in_reading_order()
{
  if (nregularccs<2) return;
  CC *ccarray = new CC[nregularccs];
  // Copy existing ccarray (but segregate special ccs)
  int ccid;
  for(ccid=0; ccid<nregularccs; ccid++)
    ccarray[ccid] = ccs[ccid];
  // Sort the ccarray list into top-to-bottom order.
  qsort (ccarray, nregularccs, sizeof(CC), top_edges_descending);
  // Subdivide the ccarray list roughly into text lines [LYB]
  // - Determine maximal top deviation
  int maxtopchange = width / 40;
  if (maxtopchange < 32) 
    maxtopchange = 32;
  // - Loop until processing all ccs
  int ccno = 0;
  int *bottoms = new int[nregularccs];
  while (ccno < nregularccs)
    {
      // - Gather first line approximation
      int nccno;
      int sublist_top = ccarray[ccno].bb.ymax-1;
      int sublist_bottom = ccarray[ccno].bb.ymin;
      for (nccno=ccno; nccno < nregularccs; nccno++)
        {
          if (ccarray[nccno].bb.ymax-1 < sublist_bottom) break;
          if (ccarray[nccno].bb.ymax-1 < sublist_top - maxtopchange) break;
          int bottom = ccarray[nccno].bb.ymin;
          bottoms[nccno-ccno] = bottom;
          if (bottom < sublist_bottom)
            sublist_bottom = bottom;
        }
      // - If more than one candidate cc for the line
      if (nccno > ccno + 1)
        {
          // - Compute median bottom
          qsort(bottoms, nccno-ccno, sizeof(int), integer_ascending);
          int bottom = bottoms[ (nccno-ccno-1)/2 ];
          // - Compose final line
          for (nccno=ccno; nccno < nregularccs; nccno++)
            if (ccarray[nccno].bb.ymax-1 < bottom)
              break;
          // - Sort final line
          qsort (ccarray+ccno, nccno-ccno, sizeof(CC), left_edges_ascending);
        }
      // - Next line
      ccno = nccno;
    }
  // Copy ccarray back and renumber the runs
  for(ccid=0; ccid<nregularccs; ccid++)
    {
      CC& cc = ccarray[ccid];
      ccs[ccid] = cc;
      for(int r=cc.frun; r<cc.frun+cc.nrun; r++)
        runs[r].ccid = ccid;
    }
  // Free memory
  delete [] bottoms;
  delete[] ccarray;
}


// -- Creates a bitmap for a particular component
GP<GBitmap>   
CCImage::get_bitmap_for_cc(const int ccid) const
{
  const CC &cc = ccs[ccid];
  const GRect &bb = cc.bb;
  GP<GBitmap> bits = GBitmap::create(bb.height(), bb.width());
  const Run *prun = & runs[(int)cc.frun];
  for (int i=0; i<cc.nrun; i++,prun++)
    {
      if (prun->y<bb.ymin || prun->y>=bb.ymax)
        G_THROW("Internal error (y bounds)");
      if (prun->x1<bb.xmin || prun->x2>=bb.xmax)
        G_THROW("Internal error (x bounds)");
      unsigned char *row = (*bits)[prun->y - bb.ymin];
      for (int x=prun->x1; x<=prun->x2; x++)
        row[x - bb.xmin] = 1;
    }
  return bits;
}


// -- Creates a JB2Image with the remaining components
GP<JB2Image> 
CCImage::get_jb2image() const
{
  GP<JB2Image> jimg = JB2Image::create();
  jimg->set_dimension(width, height);
  if (runs.hbound() < 0)
    return jimg;
  if (ccs.hbound() < 0)
    G_THROW("Must first perform a cc analysis");
  // Iterate over CCs
  for (int ccid=0; ccid<=ccs.hbound(); ccid++)
    {
      JB2Shape shape;
      JB2Blit  blit;
      shape.parent = -1;
      shape.bits = get_bitmap_for_cc(ccid);
      shape.userdata = 0;
      if (ccid >= nregularccs)
        shape.userdata |= JB2SHAPE_SPECIAL;
      blit.shapeno = jimg->add_shape(shape);
      blit.left = ccs[ccid].bb.xmin;
      blit.bottom = ccs[ccid].bb.ymin;
      jimg->add_blit(blit);
      shape.bits->compress();
    }
  // Return
  return jimg;
}




// --------------------------------------------------
// COMPLETE COMPRESSION ROUTINE
// --------------------------------------------------

struct cjb2opts {
  int  dpi;
  int  forcedpi;
  int  losslevel;
  bool verbose;
};

#if HAVE_TIFF

static int 
is_tiff(ByteStream *ref) 
{
  char magic[2];
  magic[0] = magic[1] = 0;
  ref->readall((void*)magic, sizeof(magic));
  ref->seek(0);
  if(magic[0] == 'I' && magic[1] == 'I')
    return 1;
  if(magic[0] == 'M' && magic[1] == 'M')
    return 1;
  return 0;
}

static tsize_t readproc(thandle_t h, tdata_t p, tsize_t s) { 
  ByteStream *bs = (ByteStream*)h;
  return (tsize_t) bs->readall((void*)p, (size_t)s);
}

static tsize_t writeproc(thandle_t, tdata_t, tsize_t) { 
  return -1; 
}

static toff_t seekproc(thandle_t h, toff_t offset, int mode) { 
  ByteStream *bs = (ByteStream*)h;
  bs->seek((long)offset, mode);
  return (toff_t)bs->tell(); 
}

static int closeproc(thandle_t) { 
  return 0; 
}

static toff_t sizeproc(thandle_t h) { 
  ByteStream *bs = (ByteStream*)h;
  return (toff_t) bs->size(); 
}

static int mapproc(thandle_t, tdata_t*, toff_t*) { 
  return -1; 
}

static void unmapproc(thandle_t, tdata_t, toff_t) { 
}

static void
read_tiff(CCImage &rimg, ByteStream *bs, cjb2opts &opts)
{
  TIFF *tiff = TIFFClientOpen("libtiff", "rm", (thandle_t)bs,
                              readproc, writeproc, seekproc,
                              closeproc, sizeproc, 
                              mapproc, unmapproc );
  // bitonal
  uint16 bps = 0, spp = 0;
  TIFFGetFieldDefaulted(tiff, TIFFTAG_BITSPERSAMPLE, &bps);
  TIFFGetFieldDefaulted(tiff, TIFFTAG_SAMPLESPERPIXEL, &spp);
  if (bps != 1 || spp != 1)
    G_THROW("Tiff image is not bitonal");
  // photometric
  uint16 photo = PHOTOMETRIC_MINISWHITE;
  TIFFGetFieldDefaulted(tiff, TIFFTAG_PHOTOMETRIC, &photo);
  // image size
  uint32 w, h;
  if (!TIFFGetFieldDefaulted(tiff, TIFFTAG_IMAGEWIDTH, &w) ||
      !TIFFGetFieldDefaulted(tiff, TIFFTAG_IMAGELENGTH, &h) )
    G_THROW("Tiff image size is not defined");
  // resolution
  float xres, yres;
  if (TIFFGetFieldDefaulted(tiff, TIFFTAG_XRESOLUTION, &xres) &&
      TIFFGetFieldDefaulted(tiff, TIFFTAG_YRESOLUTION, &yres) ) 
    {
      if (xres != yres)
        DjVuPrintErrorUTF8( "cjb2: X- and Y-resolution do not match\n");
      if (! opts.forcedpi)
        opts.dpi = (int) (xres + yres) / 2;
    }
  // init rimg
  rimg.init(w, h, opts.dpi);
  // allocate scanline
  tsize_t scanlinesize = TIFFScanlineSize(tiff);
  scanlinesize = MAX(scanlinesize,1);
  unsigned char *scanline = 0;
  GPBuffer<unsigned char> gscanline(scanline, scanlinesize);
  // iterate on rows
  for (int y=0; y<(int)h; y++)
    {
      int yy = h - y - 1;
      if (TIFFReadScanline(tiff, (tdata_t)scanline, y) < 0)
        G_THROW("Tiff file is corrupted (TIFFReadScanline)");
      if (photo != PHOTOMETRIC_MINISWHITE)
        for (int i=0; i<(int)scanlinesize; i++)
          scanline[i] ^= 0xff;
      int lastx=0, off=0;
      unsigned char mask=0, c=0, b=0;
      for (int x=0; x<(int)w; x++)
        {
          if (! mask) 
            {
              b = scanline[off++];
              while (b==c && x+8<(int)w )
                {
                  x = x + 8;  // speedup
                  b = scanline[off++];
                }
              mask = 0x80;
            }
          if ( (b ^ c) & mask ) 
            {
              c ^= 0xff;
              if (c)
                lastx = x;
              else
                rimg.add_single_run(yy, lastx, x-1);
            }
          mask >>= 1;
        }
      if (c)
        rimg.add_single_run(yy, lastx, w-1);
    }
  // close
  TIFFClose(tiff);
}

#endif // HAVE_TIFF


void 
cjb2(const GURL &urlin, const GURL &urlout, cjb2opts &opts)
{
  GP<ByteStream> ibs=ByteStream::create(urlin, "rb");
  CCImage rimg;

#if HAVE_TIFF
  if (is_tiff(ibs))
    read_tiff(rimg, ibs, opts);
  else
#endif
    {
      GP<GBitmap> input=GBitmap::create(*ibs);
      rimg.init(input->columns(), input->rows(), opts.dpi);
      rimg.add_bitmap_runs(*input); 
    }
  if (opts.verbose)
    DjVuFormatErrorUTF8( "%s\t%d", ERR_MSG("cjb2.runs"), 
                         rimg.runs.size() );
  
  // Component analysis
  rimg.make_ccids_by_analysis(); // obtain ccids
  rimg.make_ccs_from_ccids();    // compute cc descriptors
  if (opts.verbose)
    DjVuFormatErrorUTF8( "%s\t%d", ERR_MSG("cjb2.ccs_before"), 
                         rimg.ccs.size());
  if (opts.losslevel > 0) 
    rimg.erase_tiny_ccs();       // clean
  rimg.merge_and_split_ccs();    // reorganize weird ccs
  rimg.sort_in_reading_order();  // sort cc descriptors
  if (opts.verbose)
    DjVuFormatErrorUTF8( "%s\t%d", ERR_MSG("cjb2.ccs_after"), 
                         rimg.ccs.size());
  
  // Pattern matching
  GP<JB2Image> jimg = rimg.get_jb2image();          // get ``raw'' jb2image
  rimg.runs.empty();                                // save memory
  rimg.ccs.empty();                                 // save memory
  if (opts.losslevel>1)
    tune_jb2image_lossy(jimg, opts.dpi, opts.losslevel);
  else
    tune_jb2image_lossless(jimg);
  if (opts.verbose)
    {
      int nshape=0, nrefine=0;
      for (int i=0; i<jimg->get_shape_count(); i++) {
        if (!jimg->get_shape(i).bits) continue;
        if (jimg->get_shape(i).parent >= 0) nrefine++; 
        nshape++; 
      }
      DjVuFormatErrorUTF8( "%s\t%d\t%d", ERR_MSG("cjb2.shapes"), 
                           nshape, nrefine);
    }
  
  // Code
  GP<ByteStream> obs=ByteStream::create(urlout, "wb");
  GP<IFFByteStream> giff=IFFByteStream::create(obs);
  IFFByteStream &iff=*giff;
  // -- main composite chunk
  iff.put_chunk("FORM:DJVU", 1);
  // -- ``INFO'' chunk
  GP<DjVuInfo> ginfo=DjVuInfo::create();
  DjVuInfo &info=*ginfo;
  info.height = rimg.height;
  info.width = rimg.width;
  info.dpi = opts.dpi;
  iff.put_chunk("INFO");
  info.encode(*iff.get_bytestream());
  iff.close_chunk();
  // -- ``Sjbz'' chunk
  iff.put_chunk("Sjbz");
  jimg->encode(iff.get_bytestream());
  iff.close_chunk();
  // -- terminate main composite chunk
  iff.close_chunk();
  // Finished!
}
      





// --------------------------------------------------
// MAIN
// --------------------------------------------------

void
usage()
{
  DjVuPrintErrorUTF8(
#ifdef DJVULIBRE_VERSION
         "CJB2 --- DjVuLibre-" DJVULIBRE_VERSION "\n"
#endif
         "Simple DjVuBitonal encoder\n\n"
         "Usage: cjb2 [options] <input-pbm-or-tiff> <output-djvu>\n"
         "Options are:\n"
         " -verbose        Displays additional messages.\n"
         " -dpi <n>        Specify image resolution (default 300).\n"
         " -clean          Cleanup image by remove small flyspecs.\n"
         " -lossy          Lossy compression (implies -clean as well)\n"
         " -losslevel <n>  Loss factor (implies -lossy, default 100)\n"
         "Encoding is lossless unless a lossy options is selected.\n" );
  exit(10);
}


int 
main(int argc, const char **argv)
{
  setlocale(LC_ALL,"");
  djvu_programname(argv[0]);
  GArray<GUTF8String> dargv(0,argc-1);
  for(int i=0;i<argc;++i)
    dargv[i]=GNativeString(argv[i]);
  G_TRY
    {
      GURL inputpbmurl;
      GURL outputdjvuurl;
      cjb2opts opts;
      // Defaults
      opts.forcedpi = 0;
      opts.dpi = 300;
      opts.losslevel = 0;
      opts.verbose = false;
      // Parse options
      for (int i=1; i<argc; i++)
        {
          GUTF8String arg = dargv[i];
          if (arg == "-dpi" && i+1<argc)
            {
              char *end;
              opts.dpi = opts.forcedpi = strtol(dargv[++i], &end, 10);
              if (*end || opts.dpi<25 || opts.dpi>1200)
                usage();
            }
          else if (arg == "-losslevel")
            {
              char *end;
              opts.losslevel = strtol(dargv[++i], &end, 10);
              if (*end || opts.losslevel<0 || opts.losslevel>200)
                usage();
            }
          else if (arg == "-lossless")
            opts.losslevel = 0;
          else if (arg == "-lossy")
            opts.losslevel = 100;
          else if (arg == "-clean") // almost deprecated
            opts.losslevel = 1;
          else if (arg == "-verbose" || arg == "-v")
            opts.verbose = true;
          else if (arg[0] == '-' && arg[1])
            usage();
          else if (inputpbmurl.is_empty())
            inputpbmurl = GURL::Filename::UTF8(arg);
          else if (outputdjvuurl.is_empty())
            outputdjvuurl = GURL::Filename::UTF8(arg);
          else
            usage();
        }
      if (inputpbmurl.is_empty() || outputdjvuurl.is_empty())
        usage();
      // Execute
      cjb2(inputpbmurl, outputdjvuurl, opts);
    }
  G_CATCH(ex)
    {
      ex.perror();
      exit(1);
    }
  G_ENDCATCH;
  return 0;
}


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