Provided by: djvulibre-bin_3.5.27.1-14build1_amd64 bug

NAME

       ddjvu - Command line DjVu decoder.

SYNOPSIS

       ddjvu -format=fmt [options] [djvufile] [outputfile]

DESCRIPTION

       Decode the DjVu file djvufile, produces the image file outputfile.

       The  DjVu  data is read from the standard input when argument djvufile is not specified or
       when it is equal to a single dash.  Similarly, the output data is written to the  standard
       output  when  argument  outputfile  is not specified or equal to a single dash.  However a
       valid output file name is always required when producing a TIFF or PDF file.

MAIN OPTIONS

       -format=fmt
              Specify the output file formats.  The recognized file formats are  pbm,  pgm,  ppm,
              pnm, rle, tiff, and pdf.

              *  Formats pbm, pgm, and ppm respectively produce a Portable Bitmap (PBM), Portable
                 Graymap (PGM), or Portable Pixmap (PPM) file.  Format pnm produces a  PBM,  PGM,
                 or PPM output file according to the color content of the output image.

              *  Format rle produces a compact run length encoded bitonal file that is understood
                 by the DjVuLibre commands cjb2 and csepdjvu.

              *  Format  tiff  produces  a  Tagged  Image  Format  (TIFF)  file  using   lossless
                 compression.   Enabling lossy JPEG compression (see option -quality below) often
                 produces much smaller files.  Commands tiffcp(1) and tiffsplit(1) are useful for
                 manipulating the resulting TIFF files.

              *  Format  pdf  produces  a  Portable Document Format (PDF) file.  Each page in the
                 resulting file is represented by an image at  the  specified  resolution,  using
                 lossless  compression.   Enabling  lossy  JPEG  compression (see option -quality
                 below) often produces much smaller files.  An alternate way to produce PDF  file
                 consists  in  first using djvups(1) and convert the resulting PostScript file to
                 PDF.  Which method gives better results depends on the contents of the DJVU file
                 and on the capabilities of the PS to PDF converter.

              When  option  -format is not specified, the extension of argument outputfile has no
              influence on the default output format.  Instead the program behavior  is  modified
              to  ensure backward compatibility with previous versions of ddjvu.  We recommend to
              always specify the output format using this option.

       -page=pagespec
              Specify which pages should be decoded.  When this  option  is  not  specified,  all
              pages of the documents are decoded and concatenated into the output file.  The page
              specification pagespec contains one or more comma-separated page  ranges.   A  page
              range  is  either  a  page  number,  or  two page numbers separated by a dash.  For
              instance, specification 1-10 outputs pages 1 to 10, and  specification  1,3,99999-4
              outputs  pages  1  and 3, followed by all the document pages in reverse order up to
              page 4.

       -eachpage
              When this option is specified, program ddjvu generates one separate file  per  page
              named  by  replacing the %d specification in outputfilename by the page number in a
              manner simular to the printf(3) function.

       -mode=mod
              Selects which layers of the DjVu image should be rendered.  Valid  rendering  modes
              are color, black, mask, foreground, and background.

              *  Rendering  mode  color  is  the  default  mode.   When the DjVu file is bitonal,
                 bitonal or gray-level output is produced depending on  the  subsampling  factor.
                 Otherwise a color image is produced.

              *  Rendering  mode  black  is useful to extract a meaningful black and white image.
                 bitonal or gray-level output is produced depending on the subsampling factor.

              *  Rendering modes mask, foreground, and background select  specific  layers  of  a
                 DjVu  image.   These  modes  can  fail  if  the  DjVu image does not contain the
                 selected layer.

       -skip  Instead of aborting when encountering a corrupted page, this option causes ddjvu to
              simply  skip  the  corrupted  page  and continue with the next.  This is useful for
              processing certain damaged files.

RESOLUTION OPTIONS

       The following options control the resolution of the output image.  The default  resolution
       is the native resolution of the DjVu file, equivalent to selecting -1.

       -n     Specify  an  integer  sub-sampling factor.  The dimensions of the full output image
              will be n times smaller than the DjVu image size.  The legal values for argument  n
              range  from  1  to  12.   Option  -1,  for instance, produces an output image whose
              resolution is equal to the resolution of the input DjVu image file.

       -subsample=n
              This is equivalent to option -n.

       -scale=mag
              Specify a magnification factor relative to the resolution stored in the DjVu image.
              Specifying  magnification of 100 produces an image suitable for displaying on a 100
              dpi device such as a computer screen.  The magnification factor  mag  can  also  be
              interpreted as the resolution of the output image expressed in dot per inch.

       -size=wxh
              Specify  the  size  of  the full output image.  Rendering the full DjVu image would
              create an output image whose width and height would not exceed w and h.  To  change
              the aspect ratio, you must also use option -aspect=no.

       -aspect=yesno
              This  option  indicates  whether  the  image aspect ratio should be preserved.  The
              defaults is to preserve the aspect ration.  This  option  permits  changes  in  the
              aspect ratio when used in combination with option -size.

OTHER OPTIONS

       -verbose
              Display  informational  messages describing the structure of the DjVu image and the
              format of the output file.

       -segment=wxh+x+y
              Specify an image segment to render.  Program ddjvu conceptually  renders  the  full
              page  using  the specified resolution, and then extracts a sub-image of width w and
              height h, starting at position (x,y) relative to the  bottom  left  corner  of  the
              page.   Both  operations  of  course happen simultaneously.  Rendering a small sub-
              image is much faster than rendering the  complete  image.   The  output  file  will
              always have size wxh when this option is specified.

       -quality=factor
              Enables  lossy  JPEG  compression for TIFF and PDF files.  This option only affects
              images that cannot be encoded using the preferred  TIFF/G4  compression.   Argument
              factor  is  a quantization factor ranging from 25 to 150.  See command cjpeg(1) for
              more information on JPEG quantization factors.  Value 80 is a good starting point.

       -quality=uncompressed
              Completely disables compression in TIFF and  PDF  files.   Although  the  resulting
              files  are  often  huge,  this  is  sometimes useful for maximal compatibility with
              hastily written software.

       -quality=deflate
              Enables DEFLATE compression for TIFF files.  Images that cannot  be  encoded  using
              the  preferred  TIFF/G4  compression  will  be  encoded with DEFLATE compression if
              available.  Otherwise the more portable PACKBITS compression is  used.   Specifying
              this option is not necessary for PDF files because this is the default behavior.

DEPRECATED OPTIONS

       Various  options  have  been  maintained  to  ensure  backward compatibility with previous
       versions of ddjvu.  When option -format is not specified, the  program  only  decodes  the
       first  page of the document and the default resolution becomes -scale=100.  Options -size,
       -scale, -segment, and -page accept an argument separated by a space.  Options -foreground,
       -background,  and  -black  are shorthands for the -mode=mod option.  Please do not rely on
       these features.

EXAMPLES

       Command

          ddjvu -format=tiff myfile.djvu myfile.tif

       decodes all pages and produces a multipage TIFF file.

       Command

          ddjvu -format=ppm -page=1-10 -eachpage -size=100x100 myfile.djvu thumb%03d.ppm

       produces 100x100 thumbnails for the first ten page of a document and outputs them  as  PPM
       files named thumb001.ppm to thumb010.ppm.

CREDITS

       The new version of this program was written by Léon Bottou <leonb@users.sourceforge.net>.

       This  program  includes  code derived from program tiff2pdf, written by Ross Finlayson and
       released under a BSD license.

SEE ALSO

       djvu(1), djview(1), pnm(5), pbm(5), pgm(5),  ppm(5),  cjpeg(1),  tiffsplit(1),  tiffcp(1),
       printf(3)