Figure 10

Detecting turned faces with an upright face detector. (a) An example of three discriminative subwindows of an upright face detector. h ₁, h ₂, and h ₃ are the associated weak classifiers. (b) The face is turned 45°, and all subwindows could be classified as non-face. To alleviate the pose problem, we propose a three-dimensional geometric transformation to adjust all subwindow positions (see (c)). Note that the weak classifier h ₃ becomes unavailable.