POTRACE - transform bitmaps into vector graphics * * * DESCRIPTION Potrace is a utility for tracing a bitmap, which means, transforming a bitmap into a smooth, scalable image. The input is a bitmap (PBM, PGM, PPM, or BMP), and the default output is one of several vector file formats. A typical use is to create EPS files from scanned data, such as company or university logos, handwritten notes, etc. The resulting image is not "jaggy" like a bitmap, but smooth. It can then be rendered at any resolution. Potrace can currently produce the following output formats: EPS, PostScript, PDF, SVG (scalable vector graphics), PGM (for easy antialiasing of pixel-based images), and XFig. An experimental Gimppath backend is also provided. Additional backends might be added in the future. A separate program, mkbitmap, is also provided. This program can act as a pre-processor for Potrace, applying scaling and various filters to an image before converting it to a bitmap. This is useful for potracing greyscale and color images. DEPENDENCIES Potrace relies on the zlib library for PostScript level 3 compression. This library is pre-installed on most modern systems. If not present, it can be obtained from http://www.gzip.org/zlib/. COMPILATION For generic compilation instructions, see the file INSTALL. In addition, the following compile time options (options to ./configure) are supported: --disable-zlib: disable PostScript level 3 compression --enable-metric: use metric units (centimeters) as default --enable-a4: use a4 as the default papersize INSTALLING If you are installing from sources, just do "make install" as root. If you are installing from a binary distribution, just copy the "potrace" and "mkbitmap" binaries to a place where the operating system expects them, such as /usr/local/bin. Also copy the files "potrace.1" and "mkbitmap.1" to a directory where the operating system looks for man pages, such as /usr/local/man/man1. For instructions on installing Potrace under Windows, see the file README-WIN. USAGE For more detailed usage information, see the man page. Usage: potrace [options] [file...] General options: -h, --help - print this help message and exit -v, --version - print version info and exit -l, --license - print license info and exit -V, --show-defaults - print compiled-in defaults and exit --progress - show progress bar Input/output options: -o, --output - output to file Backend selection: -e, --eps - EPS backend (encapsulated postscript) (default) -p, --postscript - Postscript backend -s, --svg - SVG backend (scalable vector graphics) -g, --pgm - PGM backend (portable greymap) -b, --backend - select backend by name Algorithm options: -z, --turnpolicy - how to resolve ambiguities in path decomposition -t, --turdsize - suppress speckles of up to this size (default 2) -a, --alphamax - corner threshold parameter (default 1) -n, --longcurve - turn off curve optimization -O, --opttolerance - curve optimization tolerance (default 0.2) -u, --unit - quantize output to 1/unit pixels (default 10) -d, --debug - produce debugging output of type n (n=1,2,3) Scaling and placement options: -W, --width - width of output image -H, --height - height of output image -r, --resolution [x] - resolution (in dpi) -x, --scale [x] - scaling factor (pgm backend) -S, --stretch - yresolution/xresolution -A, --rotate - rotate counterclockwise by angle -M, --margin - margin -L, --leftmargin - left margin -R, --rightmargin - right margin -T, --topmargin - top margin -B, --bottommargin - bottom margin Output options, supported by some backends: -C, --color #rrggbb - set line color (default black) --fillcolor #rrggbb - set fill color (default transparent) --opaque - make white shapes opaque --group - group related paths together Postscript/EPS options: -P, --pagesize - page size (default is letter) -c, --cleartext - do not compress the output -2, --level2 - use postscript level 2 compression (default) -3, --level3 - use postscript level 3 compression -q, --longcoding - do not optimize for file size PGM options: -G, --gamma - gamma value for anti-aliasing (default 2.2) Frontend options: -k, --blacklevel - black/white cutoff in input file (default 0.5) -i, --invert - invert bitmap Dimensions can have optional units, e.g. 6.5in, 15cm, 100pt. Default is inches (or pixels for pgm and gimppath backends). Possible input file formats are: pnm (pbm, pgm, ppm), bmp. Backends are: eps, postscript, ps, pdf, svg, pgm, gimppath, xfig. POTRACE LIBRARY (FOR DEVELOPERS) As of Potrace release 1.6, the Potrace core functionality has been separated into a library libpotrace.a. This makes it easy to integrate tracing functionality into other GPL programs. The API of the library is defined in the header file potracelib.h, and is documented in doc/potracelib.pdf. DOCUMENTATION Usage information is contained in the man page: http://potrace.sourceforge.net/potrace.html Many common questions are answered in the FAQ: http://potrace.sourceforge.net/faq.html Some examples are given on the following web pages: http://potrace.sourceforge.net/samples.html http://potrace.sourceforge.net/mkbitmap.html The inner workings of the potrace algorithm are explained here: http://potrace.sourceforge.net/potrace.pdf The potrace library is documented here: http://potrace.sourceforge.net/potracelib.pdf COPYRIGHT Copyright (C) 2001-2007 Peter Selinger This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. See also http://www.gnu.org/. See the file COPYING for details. GPG KEY The key fingerprint of Peter Selinger's GPG key is: 12A2 4B3C 3790 B688 E484 7A98 A68B CC37 CA31 696A This may be useful for authenticating future versions of Potrace.