|
Packit |
df99a1 |
.\" Copyright (c) 2001-2003 Leon Bottou, Yann Le Cun, Patrick Haffner,
|
|
Packit |
df99a1 |
.\" Copyright (c) 2001 AT&T Corp., and Lizardtech, Inc.
|
|
Packit |
df99a1 |
.\"
|
|
Packit |
df99a1 |
.\" This is free documentation; you can redistribute it and/or
|
|
Packit |
df99a1 |
.\" modify it under the terms of the GNU General Public License as
|
|
Packit |
df99a1 |
.\" published by the Free Software Foundation; either version 2 of
|
|
Packit |
df99a1 |
.\" the License, or (at your option) any later version.
|
|
Packit |
df99a1 |
.\"
|
|
Packit |
df99a1 |
.\" The GNU General Public License's references to "object code"
|
|
Packit |
df99a1 |
.\" and "executables" are to be interpreted as the output of any
|
|
Packit |
df99a1 |
.\" document formatting or typesetting system, including
|
|
Packit |
df99a1 |
.\" intermediate and printed output.
|
|
Packit |
df99a1 |
.\"
|
|
Packit |
df99a1 |
.\" This manual is distributed in the hope that it will be useful,
|
|
Packit |
df99a1 |
.\" but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
Packit |
df99a1 |
.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
Packit |
df99a1 |
.\" GNU General Public License for more details.
|
|
Packit |
df99a1 |
.\"
|
|
Packit |
df99a1 |
.\" You should have received a copy of the GNU General Public
|
|
Packit |
df99a1 |
.\" License along with this manual. Otherwise check the web site
|
|
Packit |
df99a1 |
.\" of the Free Software Foundation at http://www.fsf.org.
|
|
Packit |
df99a1 |
.TH CPALDJVU 1 "10/11/2001" "DjVuLibre-3.5" "DjVuLibre-3.5"
|
|
Packit |
df99a1 |
.SH NAME
|
|
Packit |
df99a1 |
cpaldjvu \- DjVuDocument encoder for low-color images.
|
|
Packit |
df99a1 |
|
|
Packit |
df99a1 |
.SH SYNOPSIS
|
|
Packit |
df99a1 |
.BI "cpaldjvu [" "options" "] " "inputppmfile" " " "outputdjvufile"
|
|
Packit |
df99a1 |
|
|
Packit |
df99a1 |
.SH DESCRIPTION
|
|
Packit |
df99a1 |
Program
|
|
Packit |
df99a1 |
.B cpaldjvu
|
|
Packit |
df99a1 |
is a DjVuDocument encoder for images containing few colors. It performs best
|
|
Packit |
df99a1 |
on images containing large solid color areas such as screen dumps.
|
|
Packit |
df99a1 |
Compression ratios on such images can be much higher than those achieved by
|
|
Packit |
df99a1 |
.SM GIF
|
|
Packit |
df99a1 |
or
|
|
Packit |
df99a1 |
.SM PNG
|
|
Packit |
df99a1 |
compression.
|
|
Packit |
df99a1 |
|
|
Packit |
df99a1 |
This program works by first reducing the number of distinct colors to a small
|
|
Packit |
df99a1 |
specified value using a simple color quantization algorithm. The dominant
|
|
Packit |
df99a1 |
color is encoded into the background layer. The other colors are encoded into
|
|
Packit |
df99a1 |
the foreground layer.
|
|
Packit |
df99a1 |
|
|
Packit |
df99a1 |
.SH OPTIONS
|
|
Packit |
df99a1 |
.TP
|
|
Packit |
df99a1 |
.BI "-dpi " "n"
|
|
Packit |
df99a1 |
Specify the resolution information encoded into the output file expressed in
|
|
Packit |
df99a1 |
dots per inch. The resolution information encoded in DjVu files determine how
|
|
Packit |
df99a1 |
the decoder scales the image on a particular display. Meaningful resolutions
|
|
Packit |
df99a1 |
range from 25 to 6000. The default value is 300 dpi.
|
|
Packit |
df99a1 |
.TP
|
|
Packit |
df99a1 |
.BI "-colors " "n"
|
|
Packit |
df99a1 |
Specify a maximum number of distinct colors for the color quantization
|
|
Packit |
df99a1 |
algorithm. process. The default value is 256. Smaller values can produce
|
|
Packit |
df99a1 |
much smaller files.
|
|
Packit |
df99a1 |
.TP
|
|
Packit |
df99a1 |
.B "-bgwhite"
|
|
Packit |
df99a1 |
Cause the background layer to use the lightest quantified color
|
|
Packit |
df99a1 |
instead of the dominant color.
|
|
Packit |
df99a1 |
.TP
|
|
Packit |
df99a1 |
.B "-verbose"
|
|
Packit |
df99a1 |
Display informational messages while running.
|
|
Packit |
df99a1 |
|
|
Packit |
df99a1 |
.SH REMARKS
|
|
Packit |
df99a1 |
The color quantization might introduce severe degradation if the image
|
|
Packit |
df99a1 |
contains photographic areas with a large number of very similar colors.
|
|
Packit |
df99a1 |
Color quantization problems might be solved by pre-processing
|
|
Packit |
df99a1 |
the input file with a different quantization program such as
|
|
Packit |
df99a1 |
.BR ppmquant .
|
|
Packit |
df99a1 |
Avoid using the error diffusion dithering algorithm.
|
|
Packit |
df99a1 |
This algorithm generates random dithering patterns that
|
|
Packit |
df99a1 |
might be very costly to encode.
|
|
Packit |
df99a1 |
|
|
Packit |
df99a1 |
.SH BUGS
|
|
Packit |
df99a1 |
This program should be rewritten as a pre-processor for
|
|
Packit |
df99a1 |
.BR csepdjvu .
|
|
Packit |
df99a1 |
|
|
Packit |
df99a1 |
.SH CREDITS
|
|
Packit |
df99a1 |
This program was initially written by L\('eon Bottou
|
|
Packit |
df99a1 |
<leonb@users.sourceforge.net> and was improved by Bill Riemers
|
|
Packit |
df99a1 |
<docbill@sourceforge.net> and many others.
|
|
Packit |
df99a1 |
|
|
Packit |
df99a1 |
.SH SEE ALSO
|
|
Packit |
df99a1 |
.BR djvu (1),
|
|
Packit |
df99a1 |
.BR pbm (5),
|
|
Packit |
df99a1 |
.BR ppmquant (1),
|
|
Packit |
df99a1 |
.BR pnmtogif (1),
|
|
Packit |
df99a1 |
.BR pnmtopng (1)
|