// -- 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<h; j++)
{
const GPixel *p = (*ginput)[j];
for (int i=0; i<w; 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<w;x++)
{
prevline[x]=bgindex;
}
for (int y=0; y<h; y++)
{
int x;
const GPixel *row = (*ginput)[y];
for(x=0;x<w;x++)
{
line[x] = pal.color_to_index(row[x]);
if (opts.bgwhite && row[x]==GPixel::WHITE)
line[x] = bgindex;
}
for(x=0;x<w;)
{
int x1 = x;
int index = line[x++];
while (x<w && line[x]==index) { x++; }
if (index != bgindex)
{
xruncount++;
rimg.add_single_run(y, x1, x-1, index);
}
}
for(x=0;x<w;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<nccs; 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<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("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!
}
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!
}
