1. Removing and weighting outliers
2. Robust Estimators
3. Projection Pursuit Techniques
RAPCA (ROBUST@Leuven, Belgium) (Matlab)
M. Hubert, P. Rousseeuw, S. Verboven, "A fast method for robust principal components with applications to chemometrics", 2001.
4. Mixed techniques
ROBPCA (ROBUST@Leuven, Belgium) (Matlab)
M. Hubert, P. Rousseeuw, K. Vanden Branden, "ROBPCA: A New Approach to Robust Principal Component Analysis", Technometrics, Volume 47, No. 1, pages 64-49, February 2005.