“…Instead of computing a transformation matrix (the [u (20)) aimed for representation of the entire dataset (PCA), LDA seeks to find a transformation matrix which is based on maximizing between class scatter and minimizing within class scatter. The eigenvector in the LDA transformation matrix with the largest eigenvalue is known as Fisher's linear discriminant [43], which by itself has also been used for face detection [179,203]. PCA is aimed at representation, while LDA aims for discrimination and is therefore appropriate for face detection when the class of faces and nonfaces is divided into subclasses.…”