Orientation analysis for rotated human face detection

In this paper, we present a framework of orientation analysis for rotated human face detection. A novel orientation histogram is constructed for statistical analysis of face images, which can show a proper symmetry with respect to the orientation of the principal axis and a local peak at its orthogonal orientation. By analyzing the orientation histogram, we can easily find the principal axis'' orientation of the rotated face. Then an upright frontal face detector based on orientation analysis and other knowledge is designed to verify the given face. The experimental results illustrate the effectiveness of our framework. [Copyright &y& Elsevier]