The Freehand Formula Entry System was first created by Steve Smithies in 1999 as a pen-based equation editor, implemented in C++ and Tcl/Tk. At the time Steve was a Master's student at the University of Otago (NZ) under the supervision of Kevin Novins.

Since that time, a number of others have contributed to and changed FFES. In the new release (0.4, August 2007) a new operation has been added to import symbols from images, a new version of the parser (symbol layout analyzer) added, and the interface cleaned up.

Recognition results may be copied and pasted from FFES to other applications. Current outputs include symbol recognition results, layout results, LaTeX, and operator trees. Recognition results are visualized using symbols drawn behind the user's input, as an image, and through the "Align" operation, which morphs symbols to visualize the recognized symbol layout.

FFES is being distributed under the GNU Public License (Version 2). The newest version of FFES runs under Linux and MacOS (Darwin). Older versions (including a Windows/Cygwin version) are also available. Please send any bug reports or questions to Richard Zanibbi.

Contributors:

• FFES: Steve Smithies, Kevin Novins, Richard Zanibbi, Arlis Rose, David Tausky, Nick Willan, Ling Zhang, Joshua Zimler
• CIT: James Arvo, Xavier Fan, Vladimir Fedorov, Yuanshan Guo, Kevin Novins, Steve Smithies, David Mancel, Richard Zanibbi, Joshua Zimler
• DRACULAE: Richard Zanibbi, Eric Bailey (MacOSX port), Ling Zhang (ExtendedDRACULAE)

Release Notes

New Release (0.4)

• This version of FFES uses the ExtendedDRACULAE parser developed by Ling Zhang in 2005, which produces more than one interpretation (Note: DRACULAE 0.3 is still available). The interface has been changed to make it possible to see these, and improved in other ways such as making it easier to copy and paste different types of output, and save user preferences in a ~/.ffesrc file.
• In summer 2006 Joshua Zimler did a significant amount of work on extending FFES to support image recognition. FFES now includes an image import function. Recognition is currently weak, but a framework has been put in place that we hope will be of some use to others.

Previous Release (0.3.1)

• Release 0.3.1 (May 2004) provides a number of bug fixes and improvements, particularly for the symbol correction facility, which is now simply a pop-up menu. CIT has been updated for compatability with modern C++ compilers (thanks goes here to David Mancel, who provided a patch for this). Also, for the Linux version DRACULAE is now compiled rather than interpreted, and image generation is now performed using dvi2bitmap, making the system significantly faster.

• Currently the system runs fastest under Linux, where the 'dvi2bitmap' LaTeX .dvi rendering program is used. The Windows/Cygwin version uses a slower conversion via 'dvips' and the Img library that comes with the ActiveTcl distribution of Tcl/Tk. LaTeX image rendering is not yet working in the MacOSX version (see the screenshot above), and I have not had an opportunity to build the MacOSX version myself.

• Download the latest FFES here.
• Decompress (using "bunzip2") and then untar (using "tar -xf") the file
• Follow the instructions located in the ffes_0.4/INSTALL file.

Linux (version 0.3.1, May 2004)

1. First, download, build, and install dvi2bitmap. NOTE: Make sure that .gif image support had been compiled in using the -V option ("dvi2bitamp -V").
2. Then download and install TXL. Note: make sure you login as the root user, or that USERNAME=root when installing TXL.
3. Now download FFES 0.3.1 (for Linux) (as a gzipped tar archive)
4. Uncompress and untar the archive, and then follow the instructions in the ffes_0.3.1/INSTALL file.

Windows/Cygwin (version 0.3.1, May 2004)

1. If you have not already, install Cygwin; make sure that you install the LaTeX packages. NOTE: Make sure that the default text file format is set to "Unix."
2. Install ActiveTcl.
3. Install TXL for Windows. NOTE: Make sure to run the TXL install script (Install.bat) from within a Cygwin shell, and that you or the person installing TXL has 'administrator' priveleges.
4. Now download FFES 0.3.1 (for Cygwin) (as a gzipped tar archive)
5. Uncompress and untar the archive, and then follow the instructions in the ffes_0.3.1/INSTALL file.

MacOSX (version 0.2)

1. Download FFES for MacOSX.
2. Uncompress and untar the archive, and then follow the instructions in the MacOSX_FFES/INSTALL file.

Support (Funding)

This research has been supported by the Natural Sciences and Engineering Research Council of Canada, and the National Science Foundation (USA). Also, Virtual Ink donated a mimio to the project in 2000.

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Publications

About FFES and CIT:

• Steve Smithies. Freehand Formula Entry System. Master's thesis, University of Otago, Dunedin, New Zealand, May 1999.
• S. Smithies, K. Novins, J. Arvo. A Handwriting-Based Equation Editor, In Proc. Graphics Interface, Kingston, Ontario, Canada, June 1999.
• S. Smithies, K. Novins, and J. Arvo. Equation Entry and Editing via Handwriting and Gesture Recognition. Behaviour and Information Technology, 20(1):53-67, 2001.
• Richard Zanibbi, Kevin Novins, James Arvo and Katherine Zanibbi. Aiding Manipulation of Handwritten Mathematical Expressions through Style-Preserving Morphs, In Proceedings of Graphics Interface 2001, Ottawa, Canada, June 2001, pp. 127-134.

About DRACULAE:

• Richard Zanibbi, Dorothea Blostein and James R. Cordy. Baseline Structure Analysis of Handwritten Mathematics Notation, In Proceedings of the Sixth International Conference on Document Analysis and Recognition, Seattle, Washington, pp. 768-773, 2001.
• R. Zanibbi, D. Blostein, and J.R. Cordy. Recognizing Mathematical Expressions Using Tree Transformation. IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 24, No. 11, pp. 1455-1467, November 2002.
• L. Zhang, D. Blostein, and R. Zanibbi. (2005) Using Fuzzy Logic to Analyze Superscript and Subscript Relations in Handwritten Mathematical Expressions, in Proc. Int'l Conf. Document Analysis and Recognition, pp. 972-976, Seoul, Korea.