A Research on the Location for Illumination Component of Poorly Illuminated Face Images in Fourier Spectrum

Abstract

Although a face image can be described in illumination-reflectance model, the illumination and reflectance components are not distinctly separated in the frequency domain after the Fourier transformation. In fact, the illumination components of a poorly illuminated face image can be divided into two regions, namely low frequency region and vertical center region. This paper proposed two methods to identify the locations of illumination component in the face images which consist of different subjects and illumination directions. By using inspection method and mean square error (MSE) function, the illumination locations can be determined accurately. The largest location of illumination component discovered via the research will be used as reference parameters to design a customized filter before it is implemented in homomorphic filtering technique.