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.