NAME
djvudigital - creates DjVu files from PS or PDF files.
SYNOPSIS
djvudigital [options]
inputfile [outputfile]
DESCRIPTION
This program creates a DjVu file from the
PostScript (.ps), GZipped PostScript (.ps.gz),
Encapsulated PostScript (.eps), or Portable Document Format
(.pdf) file inputfile.
The output file name is either given by argument
outputfile or generated by replacing the input file name
suffixes by the DjVu suffix (.djvu).
PREREQUISITES
This program depends on a specific GhostScript driver. If your
GhostScript program does not provide this driver, please check
.
OPTIONS
- --verbose, -v
- Displays more informational messages while converting the file.
- --quiet, -q
- Do not display informational messages while converting the
file.
- --dpi=resolution
- Specify the desired resolution to resolution dots per
inch. The default is 300 dpi.
- --psrotate=angle
- Rotate the PostScript file by angle degrees clockwise.
Only the values 0, 90, 180, and 270 are
supported. This option only applies to PostScript files. PDF files
are always converted according to their native orientation.
- --epsf=disposition
- Specify how to handle Encapsulated PostScript files. Argument
disposition can take the values crop, fit, and
ignore. The default disposition crop creates a DjVu
file whose size matches the bounding box of the Encapsulated
PostScript file. Value fit rescales the graphics to the
default page size. Value ignore disables all Encapsulated
PostScript specific code. This option requires Ghostscript 7.07 or
better.
- --exact-color
- Enables a more accurate rendering of the colors. This option
requires GhostScript 6.52 or better.
- --threshold=thres
- Specify a threshold for the foreground/background separation
code. Acceptable values of thres range from 0 to 100. Larger
values place more information into the foreground layer. The
default threshold value is 80.
- --bg-subsample=sub
- Specify the background subsampling ratio. Argument sub
must be an integer between 1 and 6. The default value is 3.
- --bg-slices=n+...+n
- Specify the encoding quality of the background layer. The
syntax for the argument is similar to that described for the
-slice option of command c44. The default is
72+11+10+10.
- --fg-colors=ncolors
- Specify the maximum number of distinct colors in the foreground
layer. Argument ncolors can take integer values between 1
and 4000. The default value is 256.
- --fg-image-colors=ncolors
- Specify the maximum number of distinct colors in an image for
considering encoding it into the foreground layer. Argument
ncolors can take integer values between 1 and 4000. The
default value is 256.
- --words
- Extract the text from the PostScript code and incorporates this
information into the DjVu file. This option records the location of
every word.
- --lines
- Extract the text from the PostScript code and incorporates this
information into the DjVu file. This option saves a few bytes by
only recording the location of each line.
-
--gsarg=arg1[,arg2,...,argN
]
- Insert extra arguments on the GhostScript command line.
-
--cseparg=arg1[,arg2,...,argN
]
- Insert extra arguments on the command line of program
csepdjvu or msepdjvu.
- --help
- Display the manual page for djvudigital.
- --check
- Display the names of the auxiliary programs found by
djvudigital.
GHOSTSCRIPT ISSUES
Program djvudigital internally relies on a specific
Ghostscript driver named djvusep. This driver analyzes the
logical structure of the sequence of PostScript rendering commands
and decides to execute each command into either the foreground or
the background layer. The GhostScript driver produces a separated
data file that is then compressed using the DjVuLibre program
csepdjvu.
Before processing the input file, program djvudigital
searches a Ghostscript executable providing the djvusep
driver. The search starts with the file specified by the
environment variable GSDJVU and continues with command line
executables named gs and gsdjvu.
The DjVuLibre source code contains instruction to compile such a
GhostScript executable. More information can be obtained from
.
CSEPDJVU ISSUES
The output of the djvusep GhostScript driver must be
processed by the DjVuLibre program csepdjvu. This program
can also be replaced by the the proprietary Lizardtech program
msepdjvu. Before processing the input file, program
djvudigital searches such an executable. The search starts
with the file specified by the environment variable CSEPDJVU
and continues with command line executables named msepdjvu
and csepdjvu.
CREDITS
The first version of this converter was written by L'eon Bottou
<leonb@users.sourceforge.net>
in AT&T Labs. The DjVuLibre version is derived from code
graciously released by Lizardtech in January 2004.
BUGS
Program djvudigital can only process input files that
GhostScript can process properly.
SEE ALSO
djvu(1),
csepdjvu(1),
c44(1),
gs(1),
gzip(1)