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diff --git a/doc/asciidoc/filters/latex/latex2png.py b/doc/asciidoc/filters/latex/latex2png.py
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+#!/usr/bin/env python
+'''
+NAME
+    latex2png - Converts LaTeX source to PNG file
+
+SYNOPSIS
+    latex2png [options] INFILE
+
+DESCRIPTION
+    This filter reads LaTeX source text from the input file
+    INFILE (or stdin if INFILE is -) and renders it to PNG image file.
+    Typically used to render math equations.
+
+    Requires latex(1), dvipng(1) commands and LaTeX math packages.
+
+OPTIONS
+    -D DPI
+        Set the output resolution to DPI dots per inch. Use this option to
+        scale the output image size.
+
+    -o OUTFILE
+        The file name of the output file. If not specified the output file is
+        named like INFILE but with a .png file name extension.
+
+    -m
+        Skip if the PNG output file is newer that than the INFILE.
+        Compares timestamps on INFILE and OUTFILE. If
+        INFILE is - (stdin) then compares MD5 checksum stored in file
+        named like OUTFILE but with a .md5 file name extension.
+        The .md5 file is created if the -m option is used and the
+        INFILE is - (stdin).
+
+    -v
+        Verbosely print processing information to stderr.
+
+    --help, -h
+        Print this documentation.
+
+    --version
+        Print program version number.
+
+SEE ALSO
+    latex(1), dvipng(1)
+
+AUTHOR
+    Written by Stuart Rackham, <srackham@gmail.com>
+    The code was inspired by Kjell Magne Fauske's code:
+    http://fauskes.net/nb/htmleqII/
+
+    See also:
+    http://www.amk.ca/python/code/mt-math
+    http://code.google.com/p/latexmath2png/
+
+COPYING
+    Copyright (C) 2010 Stuart Rackham. Free use of this software is
+    granted under the terms of the MIT License.
+'''
+
+# Suppress warning: "the md5 module is deprecated; use hashlib instead"
+import warnings
+warnings.simplefilter('ignore',DeprecationWarning)
+
+import os, sys, tempfile, md5
+
+VERSION = '0.1.0'
+
+# Include LaTeX packages and commands here.
+TEX_HEADER = r'''\documentclass{article}
+\usepackage{amsmath}
+\usepackage{amsthm}
+\usepackage{amssymb}
+\usepackage{bm}
+\newcommand{\mx}[1]{\mathbf{\bm{#1}}} % Matrix command
+\newcommand{\vc}[1]{\mathbf{\bm{#1}}} % Vector command
+\newcommand{\T}{\text{T}}             % Transpose
+\pagestyle{empty}
+\begin{document}'''
+
+TEX_FOOTER = r'''\end{document}'''
+
+# Globals.
+verbose = False
+
+class EApp(Exception): pass     # Application specific exception.
+
+def print_stderr(line):
+    sys.stderr.write(line + os.linesep)
+
+def print_verbose(line):
+    if verbose:
+        print_stderr(line)
+
+def write_file(filename, data, mode='w'):
+    f = open(filename, mode)
+    try:
+        f.write(data)
+    finally:
+        f.close()
+
+def read_file(filename, mode='r'):
+    f = open(filename, mode)
+    try:
+        return f.read()
+    finally:
+        f.close()
+
+def run(cmd):
+    global verbose
+    if verbose:
+        cmd += ' 1>&2'
+    else:
+        cmd += ' 2>%s 1>&2' % os.devnull
+    print_verbose('executing: %s' % cmd)
+    if os.system(cmd):
+        raise EApp, 'failed command: %s' % cmd
+
+def latex2png(infile, outfile, dpi, modified):
+    '''Convert LaTeX input file infile to PNG file named outfile.'''
+    outfile = os.path.abspath(outfile)
+    outdir = os.path.dirname(outfile)
+    if not os.path.isdir(outdir):
+        raise EApp, 'directory does not exist: %s' % outdir
+    texfile = tempfile.mktemp(suffix='.tex', dir=os.path.dirname(outfile))
+    basefile = os.path.splitext(texfile)[0]
+    dvifile = basefile + '.dvi'
+    temps = [basefile + ext for ext in ('.tex','.dvi', '.aux', '.log')]
+    skip = False
+    if infile == '-':
+        tex = sys.stdin.read()
+        if modified:
+            checksum = md5.new(tex).digest()
+            md5_file = os.path.splitext(outfile)[0] + '.md5'
+            if os.path.isfile(md5_file) and os.path.isfile(outfile) and \
+                    checksum == read_file(md5_file,'rb'):
+                skip = True
+    else:
+        if not os.path.isfile(infile):
+            raise EApp, 'input file does not exist: %s' % infile
+        tex = read_file(infile)
+        if modified and os.path.isfile(outfile) and \
+                os.path.getmtime(infile) <= os.path.getmtime(outfile):
+            skip = True
+    if skip:
+        print_verbose('skipped: no change: %s' % outfile)
+        return
+    tex = '%s\n%s\n%s\n' % (TEX_HEADER, tex.strip(), TEX_FOOTER)
+    print_verbose('tex:\n%s' % tex)
+    write_file(texfile, tex)
+    saved_pwd = os.getcwd()
+    os.chdir(outdir)
+    try:
+        # Compile LaTeX document to DVI file.
+        run('latex %s' % texfile)
+        # Convert DVI file to PNG.
+        cmd = 'dvipng'
+        if dpi:
+            cmd += ' -D %s' % dpi
+        cmd += ' -T tight -x 1000 -z 9 -bg Transparent --truecolor -o "%s" "%s" ' \
+               % (outfile,dvifile)
+        run(cmd)
+    finally:
+        os.chdir(saved_pwd)
+        for f in temps:
+            if os.path.isfile(f):
+                print_verbose('deleting: %s' % f)
+                os.remove(f)
+    if 'md5_file' in locals():
+        print_verbose('writing: %s' % md5_file)
+        write_file(md5_file, checksum, 'wb')
+
+def usage(msg=''):
+    if msg:
+        print_stderr(msg)
+    print_stderr('\n'
+                 'usage:\n'
+                 '    latex2png [options] INFILE\n'
+                 '\n'
+                 'options:\n'
+                 '    -D DPI\n'
+                 '    -o OUTFILE\n'
+                 '    -m\n'
+                 '    -v\n'
+                 '    --help\n'
+                 '    --version')
+
+def main():
+    # Process command line options.
+    global verbose
+    dpi = None
+    outfile = None
+    modified = False
+    import getopt
+    opts,args = getopt.getopt(sys.argv[1:], 'D:o:mhv', ['help','version'])
+    for o,v in opts:
+        if o in ('--help','-h'):
+            print __doc__
+            sys.exit(0)
+        if o =='--version':
+            print('latex2png version %s' % (VERSION,))
+            sys.exit(0)
+        if o == '-D': dpi = v
+        if o == '-o': outfile = v
+        if o == '-m': modified = True
+        if o == '-v': verbose = True
+    if len(args) != 1:
+        usage()
+        sys.exit(1)
+    infile = args[0]
+    if dpi and not dpi.isdigit():
+        usage('invalid DPI')
+        sys.exit(1)
+    if outfile is None:
+        if infile == '-':
+            usage('OUTFILE must be specified')
+            sys.exit(1)
+        outfile = os.path.splitext(infile)[0] + '.png'
+    # Do the work.
+    latex2png(infile, outfile, dpi, modified)
+    # Print something to suppress asciidoc 'no output from filter' warnings.
+    if infile == '-':
+        sys.stdout.write(' ')
+
+if __name__ == "__main__":
+    try:
+        main()
+    except SystemExit:
+        raise
+    except KeyboardInterrupt:
+        sys.exit(1)
+    except Exception, e:
+        print_stderr("%s: %s" % (os.path.basename(sys.argv[0]), str(e)))
+        sys.exit(1)