Welcome to the CTW website. On this page you can find information and interesting downloads on the CTW (Context Tree Weighting) algorithm, an effective lossless compression algorithm that is especially suitable for compressing text files. The CTW algorithm is invented by Frans Willems, Yuri Shtarkov and Tjalling Tjalkens, in cooperation with KPN NV. Please take note of the Intellectual Property Rights!
On this website you can find a first implementation of the context tree weighting algorithm (CTW version 0.1, see the version history) by Erik Franken and Marcel Peeters, both students of the department of electrical engineering at Eindhoven University of Technology. To begin with, you can download a binary suitable for your computer or the source code. You can also download the manual or read the manual online.
To learn more about the theory behind our implementation of CTW, read the overview section of this website. Note: you'll need some basic knowledge of information theory.
To see how this CTW implementation performs, have a look at the results page. In this section you can find the results on the Calgary corpus and the Canterbury corpus. In the recommendations section, some ideas for further improvement of the CTW implementation are proposed.
If you have any questions or suggestions you can always contact us. Finally, in the links section, some interesting links are collected.