//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- +------------------------------------------------------------------

#ifdef HAVE_CONFIG_H

# include "config.h"

#endif

#if NEED_GNUG_PRAGMAS

# pragma implementation

#endif

/** @name cpaldjvu

    {\bf Synopsis}

    \begin{verbatim}

        cpaldjvu [options] <inputppmfile> <outputdjvufile>

    \end{verbatim}

    {\bf Description}

    File #"cpaldjvu.cpp"# demonstrates a simple quasi-lossless compressor for

    low resolution, low color, images with a reduced number of colors (e.g

    screendumps).  It simply quantizes the image on a limited number of

    colors, uses the dominant color to construct a uniform background, then

    performs lossless jb2 compression for all remaining objects.  

    Options

    \begin{description}

    \item[-colors n]  Maximum number of colors during quantization (default 256)

    \item[-dpi n]     Resolution written into the output file (default 100).

    \item[-verbose]   Displays additional messages.

    \end{description}

    {\bf Remarks}

    This is an interesting alternative to GIF. It performs especially well on

    screendumps.  Compression ratios can get hurt when there are continuous

    tone segment in the image.  Demoting such segments from foreground to

    background is a pretty interesting project.  Dithered segments behave

    surprisingly well.

    @memo

    Simple encoder for low resolution, low color images.

    @author

    L\'eon Bottou <leonb@research.att.com>

*/

//@{

//@}

#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 "DjVuPalette.h"

#include "IW44Image.h"

#include "DjVuInfo.h"

#include "GOS.h"

#include "GURL.h"

#include "DjVuMessage.h"

#include "jb2tune.h"

#include "common.h"

#ifdef MIN

#undef MIN

#endif

#ifdef MAX

#undef MAX

#endif

inline int MIN(int a, int b) { return ( a

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

// --------------------------------------------------

// COLOR CONNECTED COMPONENT ANALYSIS

// --------------------------------------------------

// -- A run of pixels with the same color

struct Run    

{ 

  short y;       // vertical coordinate

  short x1;      // first horizontal coordinate

  short x2;      // last horizontal coordinate

  short color;   // color id

  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

  int color;     // color id

};

// -- 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)

  CCImage(int width, int height);

  void add_single_run(int y, int x1, int x2, int color, int ccid=0);

  GP<GBitmap> get_bitmap_for_cc(int ccid) const;

  void make_ccids_by_analysis();

  void make_ccs_from_ccids();

  void merge_and_split_ccs(int smallsize, int largesize);

  void sort_in_reading_order(); 

  void erase_cc(int ccid);

};

// -- Compares runs

static inline bool

operator <= (const Run &a, const Run &b)

{

  return (a.y

}

// -- Constructs CCImage and provide defaults

CCImage::CCImage(int width, int height)

  : height(height), width(width), nregularccs(0)

{

}

// -- Adds a run to the CCImage

inline void 

CCImage::add_single_run(int y, int x1, int x2, int color, int ccid)

{

  int index = runs.hbound();

  runs.touch(++index);

  Run& run = runs[index];

  run.y = y;

  run.x1 = x1;

  run.x2 = x2;

  run.color = color;

  run.ccid = ccid;

}

// -- Performs color 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 color = runs[n].color;

      int id = (umap.hbound() + 1);

      // iterate over previous line runs

      if (p>0) p--;

      for(;runs[p].y < y-1;p++);

      for(;(runs[p].y < y) && (runs[p].x1 <= x2);p++ )

        {

          if ( runs[p].x2 >= x1 )

            {

              if (runs[p].color == color)

                {

                  // previous run touches current run and has same color

                  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 = -1;

  for (n=0; n<=runs.hbound(); n++)

    if (pruns[n].ccid > maxccid)

      maxccid = runs[n].ccid;

  GTArray<int> armap(0,maxccid);

  int *rmap = armap;

  // Renumber ccs 

  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

    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

    {

      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

    {

      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;

      cc.color = run->color;

      for (int i=0; i

        {

          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;

    }

}

// -- Helper for merge_and_split_ccs

struct Grid_x_Color 

{

  short gridi;

  short gridj;

  int color;

};

// -- Helper for merge_and_split_ccs

static inline unsigned int

hash(const Grid_x_Color &x) 

{

  return (x.gridi<<16) ^ (x.gridj<<8) ^ x.color;

}

// -- Helper for merge_and_split_ccs

static inline bool

operator==(const Grid_x_Color &x, const Grid_x_Color &y)

{

  return (x.gridi==y.gridi) && (x.gridj==y.gridj) && (x.color==y.color);

}

// -- Helper for merge_and_split_ccs

static int

makeccid(const Grid_x_Color &x, GMap<Grid_x_Color,int> &map, int &ncc)

{

  GPosition p = map.contains(x);

  if (p) return map[p];

  return map[x] = ncc++;

}

// -- Merges small ccs of similar color and splits large ccs

void

CCImage::merge_and_split_ccs(int smallsize, int largesize)

{

  int ncc = ccs.size();

  int nruns = runs.size();

  int splitsize = largesize;

  if (ncc <= 0) return;

  // Associative map for storing merged ccids

  GMap<Grid_x_Color,int> map;

  nregularccs = ncc;

  // Set the correct ccids for the runs

  for (int ccid=0; ccid

    {

      CC* cc = &ccs[ccid];

      if (cc->nrun <= 0) continue;

      Grid_x_Color key;

      key.color = cc->color;

      int ccheight = cc->bb.height();

      int ccwidth = cc->bb.width();

      if (ccheight<=smallsize && ccwidth<=smallsize)

        {

          key.gridi = (cc->bb.ymin+cc->bb.ymax)/splitsize/2;

          key.gridj = (cc->bb.xmin+cc->bb.xmax)/splitsize/2;

          int newccid = makeccid(key, map, ncc);

          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];

              key.gridi = r->y/splitsize;

              key.gridj = r->x1/splitsize;

              int gridj_end = r->x2/splitsize;

              int gridj_span = gridj_end - key.gridj;

              r->ccid = makeccid(key, map, ncc);

              if (gridj_span>0)

                {

                  // truncate current run 

                  runs.touch(nruns+gridj_span-1);

                  r = &runs[runid];

                  int x = key.gridj*splitsize + splitsize;

                  int x_end = r->x2;

                  r->x2 = x-1;

                  // append additional runs to the runs array

                  while (++key.gridj < gridj_end)

                    {

                      Run& newrun = runs[nruns++];

                      newrun.y = r->y;

                      newrun.x1 = x;

                      x += splitsize;

                      newrun.x2 = x-1;

                      newrun.color = key.color;

                      newrun.ccid = makeccid(key, map, ncc);

                    }

                  // append last run to the run array

                  Run& newrun = runs[nruns++];

                  newrun.y = r->y;

                  newrun.x1 = x;

                  newrun.x2 = x_end;

                  newrun.color = key.color;

                  newrun.ccid = makeccid(key, map, ncc);

                }

            }

        }

    }

  // 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

    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

  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

    {

      CC& cc = ccarray[ccid];

      ccs[ccid] = cc;

      for(int r=cc.frun; 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

    {

      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;

}

// -- Marks cc for deletion

void 

CCImage::erase_cc(int ccid)

{

  CC &cc = ccs[ccid];

  Run *r = &runs[cc.frun];

  int nr = cc.nrun;

  cc.nrun = 0;

  cc.npix = 0;

  while (--nr >= 0)

    (r++)->ccid = -1;  // will be deleted by make_ccs_from_ccids()

}

// --------------------------------------------------

// DEMOTION OF FOREGROUND CCS TO BACKGROUND STATUS

// --------------------------------------------------

// ISSUE: DEMOTION OF CCS (UNIMPLEMENTED) 

// The current code uses a single color for the background layer.  Many large,

// non matching, ccs however may be better encoded as part of the background

// layer.  A way to achieve this could be to consider each cc and evaluate the

// costs of coding it as foreground (does it match other ccs, does it comes

// with a complex geometry) or background (does its color blend smoothly with

// the surrounding parts of the background image).  One just needs then to

// remove the demoted ccs from the mask using CCImage::erase_cc() and

// recompute the ccs using CCImage::make_ccs_from_ccids().  Defining the

// compilation symbols BACKGROUND_SUBSAMPLING_FACTOR and

// PROGRESSIVE_BACKGROUND will enable code for computing the background from

// the input image and the provided mask.

// --------------------------------------------------

// MAIN COMPRESSION ROUTINE

// --------------------------------------------------

// -- Options for low color compression

struct cpaldjvuopts

{

  int ncolors;

  int dpi;

  bool verbose;

  bool bgwhite;

};

// -- Compresses low color pixmap.

void 

cpaldjvu(ByteStream *ibs, GURL &urlout, const cpaldjvuopts &opts)

{

  GP<GPixmap> ginput=GPixmap::create(*ibs);

  int w = ginput->columns();

  int h = ginput->rows();

  int dpi = MAX(200, MIN(900, opts.dpi));

  int largesize = MIN(500, MAX(64, dpi));

  int smallsize = MAX(2, dpi/150);

  // Compute optimal palette and quantize input pixmap

  GP<DjVuPalette> gpal=DjVuPalette::create();

  DjVuPalette &pal=*gpal;

  GPixel bgcolor;

  int bgindex = -1;

  if (! opts.bgwhite)

    {

      bgindex = pal.compute_pixmap_palette(*ginput, opts.ncolors);

      pal.index_to_color(bgindex, bgcolor);

    }

  else

    {

      bgcolor = GPixel::WHITE;

      pal.histogram_clear();

      for (int j=0; j

        {

          const GPixel *p = (*ginput)[j];

          for (int i=0; i

            if (p[i] != GPixel::WHITE)

              pal.histogram_add(p[i], 1);

        }

      pal.compute_palette(opts.ncolors);

    }

  if (opts.verbose)

    DjVuFormatErrorUTF8( "%s\t%d\t%d\t%d",

                         ERR_MSG("cpaldjvu.quantizied"), 

                         w, h, pal.size());

  if (opts.verbose && !opts.bgwhite)

    DjVuPrintErrorUTF8("cpaldjvu: background color is #%02x%02x%02x.\n", 

                       bgcolor.r, bgcolor.g, bgcolor.b);

  // Fill CCImage with color runs

  int xruncount=0,yruncount=0;

  CCImage rimg(w, h);

  int *line;

  GPBuffer<int> gline(line,w);

  int *prevline;

  GPBuffer<int> gprevline(prevline,w);

  for (int x=0;x

  {

    prevline[x]=bgindex;

  }

  for (int y=0; y

    {

      int x;

      const GPixel *row = (*ginput)[y];

      for(x=0;x

        {

          line[x] = pal.color_to_index(row[x]);

          if (opts.bgwhite && row[x]==GPixel::WHITE)

            line[x] = bgindex;

        }

      for(x=0;x

        {

          int x1 = x;

          int index = line[x++];

          while (x

          if (index != bgindex)

            {

              xruncount++;

              rimg.add_single_run(y, x1, x-1, index);

            }

        }

      for(x=0;x

        if(prevline[x] != line[x]) yruncount++;

      gprevline.swap(gline);

    }

  ginput = 0; //save memory

  if (opts.verbose)

    DjVuFormatErrorUTF8( "%s\t%d", ERR_MSG("cpaldjvu.color_runs"), 

                         rimg.runs.size());

  // Perform Color Connected 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("cpaldjvu.ccs_before"), 

                         rimg.ccs.size());

  rimg.merge_and_split_ccs(smallsize,largesize);  // Eliminates gross ccs

  if (opts.verbose)

    DjVuFormatErrorUTF8( "%s\t%d", ERR_MSG("cpaldjvu.ccs_after"), 

                         rimg.ccs.size());

  rimg.sort_in_reading_order();                   // Sort cc descriptors

  // Create JB2Image and fill colordata

  GP<JB2Image> gjimg=JB2Image::create();

  JB2Image &jimg=*gjimg;

  jimg.set_dimension(w, h);

  int nccs = rimg.ccs.size();

  for (int ccid=0; ccid

    {

      JB2Shape shape;

      JB2Blit  blit;

      shape.parent = -1;

      shape.userdata = 0;

      if (ccid >= rimg.nregularccs)

        shape.userdata |= JB2SHAPE_SPECIAL;

      shape.bits = rimg.get_bitmap_for_cc(ccid);

      shape.bits->compress();

      CC& cc = rimg.ccs[ccid];

      blit.shapeno = jimg.add_shape(shape);

      blit.left = cc.bb.xmin;

      blit.bottom = cc.bb.ymin;

      int blitno = jimg.add_blit(blit);

      pal.colordata.touch(blitno);

      pal.colordata[blitno] = cc.color;

    }

  // Organize JB2Image

  tune_jb2image_lossless(&jimg);

  if (opts.verbose)

    {

      int nshape=0, nrefine=0;

      for (int i=0; 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("cpaldjvu.cross_code"), 

                       nshape, nrefine);

    }

  // Create background image

#ifdef BACKGROUND_SUBSAMPLING_FACTOR

  // -- we may create the background by masking and subsampling

  GP<GPixmap> ginputsub=GPixmap::create();

  GPixmap &inputsub=*ginputsub;

  GP<GBitmap> mask = jimg.get_bitmap(BACKGROUND_SUBSAMPLING_FACTOR);

  inputsub.downsample(&input, BACKGROUND_SUBSAMPLING_FACTOR);

  GP<IW44Image> iwimage=IW44Image::create(inputsub, mask);

#else

  // -- but who cares since the background is uniform.

  GP<GPixmap> ginputsub=GPixmap::create((h+11)/12, (w+11)/12, &bgcolor);

  GPixmap &inputsub=*ginputsub;

  GP<IW44Image> iwimage=IW44Image::create_encode(inputsub);

#endif

  // Assemble DJVU file

  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

  iff.put_chunk("INFO");

  GP<DjVuInfo> ginfo=DjVuInfo::create();

  DjVuInfo info=*ginfo;

  info.height = h;

  info.width = w;

  info.dpi = opts.dpi;

  info.encode(*iff.get_bytestream());

  iff.close_chunk();

  // -- ``Sjbz'' chunk

  iff.put_chunk("Sjbz");

  jimg.encode(iff.get_bytestream());

  iff.close_chunk();

  // -- ``FGbz'' chunk

  iff.put_chunk("FGbz");

  pal.encode(iff.get_bytestream());

  iff.close_chunk();

  // -- ``BG44'' chunk

  IWEncoderParms iwparms;

#ifdef PROGRESSIVE_BACKGROUND

  // ----- we may use several chunks to enable progressive rendering ...

  iff.put_chunk("BG44");

  iwparms.slices = 74;

  iwimage->encode_chunk(iff, iwparms);

  iff.close_chunk();

  iff.put_chunk("BG44");

  iwparms.slices = 87;

  iwimage->encode_chunk(iff, iwparms);

  iff.close_chunk();

#endif

  // ----- but who cares when the background is so small.

  iff.put_chunk("BG44");

  iwparms.slices = 97;

  iwimage->encode_chunk(iff.get_bytestream(), iwparms);

  iff.close_chunk();

  // -- terminate main composite chunk

  iff.close_chunk();

  // Finished!

}  

// --------------------------------------------------

// MAIN

// --------------------------------------------------

void

usage()

{

  DjVuPrintErrorUTF8(

#ifdef DJVULIBRE_VERSION

         "CPALDJVU --- DjVuLibre-" DJVULIBRE_VERSION "\n"

#endif

         "DjVu encoder for images with few colors\n\n"

         "Usage: cpaldjvu [options] <inputppmfile> <outputdjvufile>\n"

         "Options are:\n"

         "   -colors [2-4096] Maximum number of colors during quantization (default 256).\n"

         "   -dpi [25-6000]   Resolution written into the output file (default 100).\n"

         "   -verbose         Displays additional messages.\n"

         "   -bgwhite         Use the lightest color for background (usually white).\n"

         );

  exit(10);

}

int 

main(int argc, const char **argv)

{

  DJVU_LOCALE;

  GArray<GUTF8String> dargv(0,argc-1);

  for(int i=0;i

    dargv[i]=GNativeString(argv[i]);

  G_TRY

    {

      GURL inputppmurl;

      GURL outputdjvuurl;

      // Defaults

      cpaldjvuopts opts;

      opts.dpi = 100;

      opts.ncolors = 256;

      opts.verbose = false;

      opts.bgwhite = false;