The Negative Effects of Whitening Transformation in Face Recognition
Whitening transformation has widely been used in face recognition. Typically it is used in one of four ways: as a data preprocessing tool before feature extraction, to calculate statistically uncorrelated discriminant vectors, as a transitional step in calculating discriminant vectors, or as a data post-processing tool after feature extraction. The experimental studies presented in this paper demonstrate, however, that researchers’ faith in this technique is misplaced and that in fact whitening transformation is inappropriately used, and actually has a negative effect in face recognition without proper analysis.