September 17, 2019: Release 1.16

 This release consists of bugfixes and minor portability improvements.
 A potential arithmetic overflow was fixed. Rotation angles are now
 normalized to between -180 and 180. We now use binary file I/O on the
 OS/2 platform. The test suite tolerances were adjusted. The
 configuration option --enable-local-getopt was renamed as
 --with-included-getopt. Some build system improvements. Thanks to
 Henri Salo and Dave Yeo for reporting bugs and suggesting
 improvements.

August 5, 2017: Release 1.15

 This release consists of bugfixes and minor portability improvements.
 Some potential buffer overflows and arithmetic overflows were fixed,
 including CVE-2017-12067. A bug triggered by very large bitmaps has
 been fixed. A new configuration option --enable-local-getopt was
 added. Thanks to Agostino Sarubbo, Daniel Macks, and Michael Voříšek
 for reporting bugs and suggesting improvements.

February 19, 2017: Release 1.14

 This release consists of bugfixes and minor portability improvements.
 A number of bugs triggered by malformed BMP files have been fixed,
 including CVE-2016-8685 and CVE-2016-8686. Error reporting has been
 improved. The image size is now truncated when the bitmap data ends
 prematurely. It is now possible to use negative dy in bitmap
 data. Portability has been improved to encompass C++11. The default
 compiler is now clang if available. Thanks to Nelson Beebe and Martin
 Gieseking for reporting portability issues, and to Agostino Sarubbo
 for reporting bugs.

October 22, 2015: Release 1.13

 Some critical bugs in the processing of BMP files were fixed. These
 bugs allowed the program to be crashed, or potentially to be abused
 in other ways, by feeding it specially crafted BMP files. Thanks to
 Tomasz Buchert and Agostino Sarubbo for reporting these bugs.
 Portability was improved for C99 and for MSVC++. Thanks to Peter
 Breitenlohner, Nelson Beebe, and Martin Gieseking for reporting
 portability issues.

March 24, 2015: Release 1.12

 Fixed memory overflow bug triggered by very large bitmaps. Fixed
 binary file mode on 64-bit Windows. Portability improvements.

February 19, 2013: Release 1.11

 A GeoJSON backend was added; thanks to Christoph Hormann for
 contributing this. Support for bitfields in the BMP format was
 added. A minor change was made to the behavior of the alphamax
 parameter; a value of 0 now gives a true polygon.

August 19, 2011: Release 1.10

 A DXF backend was added. The output is in the drawing interchange
 format used by computer aided design software. Thanks to Jonas
 Benedett Dorr for testing. The Gimppath backend was changed to be
 compatible with current versions of Gimp. The EPS, PDF, and SVG
 backends now use high-resolution bounding boxes. The default scaling
 of the EPS, PDF, and SVG backends is now fixed at 72dpi. A new option
 --flat was added to the SVG backend. A new option --tight was added
 to remove whitespace around the input image before calculating its
 scaling and placement.

December 21, 2010: Release 1.9

 The xfig and eps backends were improved, and a fixed pagesize PDF
 backend was added. Support for BMP version 4 and version 5 files, as
 well as top-down BMP files, was added. Minor speed improvements to
 Potrace and major speed improvements to mkbitmap. A Gaussian blur
 option was added to mkbitmap. Libtool is now used to build and
 optionally install the Potrace library. An optional simplified
 progress bar was added for dumb terminals. This release also contains
 some portability improvements, cross-compilation improvements, and
 minor bug fixes.

April 9, 2007: Release 1.8

 This release contains minor bugfixes and portability improvements.
 Rotation is now implemented in the PDF backend.

March 6, 2005: Release 1.7
 
 This is a bugfix release. A bug in the progress bar code, which
 caused arithmetic exceptions on some 64-bit architectures, has been
 fixed.

February 27, 2005: Release 1.6

 This release contains an algorithm improvement that leads to a
 speedup of 20-60% over previous versions of Potrace. A new PDF
 backend was added, courtesy of Tor Andersson. An option --progress
 was added for displaying a progress bar. The Windows version of
 Potrace now uses MinGW instead of Cygwin, eliminating the need to
 install a special DLL alongside the executable programs, and solving
 some problems with wildcards and executable PostScript files. Some
 spurious "premature end of file" messages were eliminated. The
 core functionality of Potrace was separated into a library with a
 documented API, making it easier for developers to incorporate
 Potrace into other GPL-licensed software.

July 8, 2004: Release 1.5

 The LZW patent has finally expired in Canada. Therefore, postscript
 level 2 compression can now be implemented directly within Potrace,
 without having to rely on the external "compress" program. This
 release makes the necessary corrections.

March 6, 2004: Release 1.4

 This is a bugfix release. Fixed the bug which sometimes caused
 Potrace to "hang" on large input files. Also fixed some bugs in the
 compression code. The presence of the "compress" program is now
 determined at run-time, rather than compile-time. No new features or
 command line options were added.

January 15, 2004: Release 1.3

 This is primarily a bugfix release. Version 1.2 fatally crashed when
 applied to an empty (all white) bitmap. The options -2 and -3 are now
 ignored when unsupported, rather than causing an error.  There were
 some improvements to the test suite, autoconfiguration, and
 portability. The bounding box in the xfig backend was fixed, and the
 postscript output now has better page encapsulation. Bitmaps of
 dimension 0 are now tolerated better.

December 23, 2003: Release 1.2

 New experimental Gimppath and XFig backends were added.  A separate
 program mkbitmap was added, which can be used as a preprocessor to
 Potrace. It turns greyscale or color images into high-quality
 bitmaps with optional scaling and filtering. New options --opaque,
 --group, and --fillcolor were added for greater flexibility in
 generating editable PostScript and SVG output. The bitmap
 decomposition algorithm was improved and can now take advantage of
 64-bit platforms.  Portability and autoconfiguration were vastly
 improved, and a test suite was added. Runlength encoded BMP files can
 now be read. Some bugs in command line options were fixed.

August 18, 2003: Release 1.1

 The most important new feature of this release is an SVG (scalable
 vector graphics) backend. This file format can be read by vector
 graphics manipulation programs such as sodipodi, as well as web
 browsers with an SVG plugin. I also added PGM, PPM, and BMP as
 additional input file formats. The new --blacklevel and --invert
 options control how non-black-and-white images are converted to
 bitmaps before being processed by Potrace. The implementation of a
 critical function has been improved to make Potrace even faster on
 large input files; this results in speedups of up to factor 3.3
 relative to Potrace 1.0. Autoconfiguration was improved, and the code
 was polished to compile on more different architectures. The error
 messages for wrong file formats were also improved.

August 10, 2003: Release 1.0

 First public release.
