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
http://djvu.sourceforge.net/gsdjvu.html.
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.
- --sepfile
- Produces a separated data file instead of a DjVu file.
Program csepdjvu can then convert the separated data file into a
DjVu file.
- --check
- Display the names of the two auxiliary programs found by
djvudigital, namely a suitable ghostscript interpreter and a
suitable backend encoder. See the next two section for details.
- --dryrun
- Simply display the ghostscript command line generated by
djvudigital without running it. No output file is produced
- --help
- Display the manual page for 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
http://djvu.sourceforge.net/gsdjvu.html.
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 Léon 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)