The "IDF Converter" program is lost, SMI website doesn't include the programs.
Any way to open the *.idf files or convert them into any other format readable by python or MATLAB?
No, the IDF format is proprietary and encrypted, it seems to be. And SMI Vision was acquired by Apple in 2016, that's why the website is almost down. The utility you need, IDF Converter, is contained as part of an iTools bundle.
Method 1. Download from file sharing service.
The link kindly provided by Dr. Kenneth Holmqvist, Lund University.
Method 2. Search FTP servers, e.g. searchftps.net. In order to use it, you have to disable AdBlock, then try searching "iTools_setup.exe", and use dedicated downloading software like FreeDownloadManager or GetRight.