libraries/jbig2enc: Added (encoder for JBIG2).

Signed-off-by: Willy Sudiarto Raharjo <willysr@slackbuilds.org>

1 files changed, 176 insertions, 0 deletions

diff --git a/libraries/jbig2enc/jbig2.rst b/libraries/jbig2enc/jbig2.rst
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+.. RST source for jbig2(1) man page. Convert with:
+..   rst2man.py jbig2.rst > jbig2.1
+.. rst2man.py comes from the SBo development/docutils package.
+
+.. |version| replace:: 0.28
+.. |date| date::
+
+=====
+jbig2
+=====
+
+-----------------------------------
+convert image files to JBIG2 format
+-----------------------------------
+
+:Manual section: 1
+:Manual group: SlackBuilds.org
+:Date: |date|
+:Version: |version|
+
+SYNOPSIS
+========
+
+**jbig2** [*-options*] *imagefile* > *output.jb2*
+
+DESCRIPTION
+===========
+
+JBIG2 is an image compression standard from the same people who brought
+you the JPEG format. It compresses 1bpp (black and white) images only.
+
+jbig2enc is a library that encodes JBIG2 images.
+
+**jbig2** is a command-line tool that uses the jbig2enc library to convert an
+image to the JBIG2 format. *imagefile* can be in any format readable by
+leptonica (png, jpeg, tiff, gif, webp, jp2, bmp, pnm, spix). The image
+is converted to 1bbp (monochrome) before processing.
+
+Without the *-p*, *--pdf* option, the converted image is written to
+standard output. This should be redirected to a file, normally with
+the *.jb2* extension. If stdout isn't redirected to a file (or a pipe),
+the JBIG2 data will be written to the terminal, which may get confused.
+
+There is no way to have **jbig2** read an image file on standard input. This
+is by design, as it needs to seek within the file.
+
+All options must appear before the filename. With the generic encoder
+(no *-s* option), anything after the filename is silently ignored. The
+symbol encoder (*-s*) can handle multiple images (which end up as pages
+in the JBIG2 file).
+
+The *-r*, *--refine* option mentioned in the documentation and in
+the *--help* output of **jbig2** is *disabled* in this version of
+**jbig2**.
+
+OPTIONS
+=======
+
+.. some of these are from the HTML file, some from --help.
+
+-b *basename*
+  Output file root name when using symbol coding in PDF mode (*-s*
+  and *-p*). Default is **output**.
+
+-d, --duplicate-line-removal
+  When encoding generic regions each scan line can be tagged to indicate
+  that it's the same as the last scanline - and encoding that scanline
+  is skipped. This drastically reduces the encoding time (by a factor
+  of about 2 on some images) although it doesn't typically save any
+  bytes. This is an option because some versions of jbig2dec (an open
+  source decoding library) cannot handle this.
+
+-p, --pdf
+  The PDF spec includes support for JBIG2 (Syntax->Filters->JBIG2Decode in
+  the PDF references for versions 1.4 and above). However, PDF requires
+  a slightly different format for JBIG2 streams: no file/page headers or
+  trailers and all pages are numbered 1. In symbol mode the output is to
+  a series of files: symboltable and page-n (numbered from 0). By default
+  these are named **output.sym** and **output.0000**, **output.0001**,
+  etc. Use *-b* to change the base filename.
+
+-s, --symbol-mode
+  Use symbol encoding. Turn on for scanned text pages.
+
+-t *threshold*
+  Sets the fraction of pixels which have to match in order for
+  two symbols to be classed the same. This isn't strictly true, as there are
+  other tests as well, but increasing this will generally increase the number
+  of symbol classes. Default is 0.85.
+
+-T *threshold*
+  Sets the black threshold (0-255). Any gray value darker than
+  this is considered black. Anything lighter is considered white.
+  Default is 188.
+
+-O *outfile*
+  Dump a PNG of the 1 bpp image before encoding. Can be used to
+  test loss.
+
+-2, -4
+  Upscale either two or four times before converting to black and
+  white.
+
+-S
+  Segment an image into text and non-text regions. This isn't perfect, but
+  running text through the symbol compressor is terrible so it's worth doing
+  if your input has images in it (like a magazine page).
+
+--image-output
+  Set filename to which the parts which were removed by -S are written.
+  Default is PNG format.
+
+-j, --jpeg-output
+  Write images from -S as JPEG instead of PNG.
+
+-a, --auto-thresh
+  Use automatic thresholding in symbol encoder.
+
+--no-hash
+  Disables use of hash function for automatic thresholding.
+
+-v
+  Be verbose.
+
+-V, --version
+  Display version number and exit.
+
+-h, --help
+  Display help and exit.
+
+EXIT STATUS
+===========
+
+**jbig2** exits with 0 (success) status if the conversion completed
+OK, and non-zero status if anything went wrong. If standard output was
+redirected to a file, the file will be empty or invalid when non-zero
+status is returned. Diagnostic messages are printed to standard error.
+
+COPYRIGHT
+=========
+
+See the file /usr/doc/jbig2enc-|version|/COPYING for license information.
+
+This software is a description of processes which may be patented.
+
+Use of this software may require patent licenses in some countries.
+You are directed to annex I of the JBIG2 specification for information.
+
+Some information could be found at:
+    http://www.jpeg.org/jbig/index.html
+    http://www.cl.cam.ac.uk/~mgk25/jbigkit/patents/
+    http://www.jpeg.org/public/fcd14492.pdf
+    http://itscj.ipsj.or.jp/sc29/open/29view/29n55161.doc
+
+AUTHORS
+=======
+
+jbig2 and jbig2enc were written by:
+  Adam Langley <agl@imperialviolet.org>.
+
+This man page written for the SlackBuilds.org project
+by B. Watson, and is licensed under the WTFPL.
+
+SEE ALSO
+========
+
+**pdf.py(1)**, **jbig2dec(1)**
+
+Full documentation for jbig2 and jbig2enc:
+  /usr/doc/jbig2enc-|version|/jbig2enc.html
+
+The JBIG2 specification was formerly located at:
+  http://www.jpeg.org/public/fcd14492.pdf
+
+A copy can be found here:
+  http://www.hlevkin.com/Standards/fcd14492.pdf