Pattern detection in gray-scale images with polarization coding

Most of the matched filtering techniques that have been used for pattern re cognition have manipulated amplitude and phase information. Light, however, has another principal type of information that has not yet been used for p attern recognition. mie propose a matched filtering technique which manipul ates the polarization of light and shows the merits of using polarization i nformation. The amplitude transmittance of input images is coded into the t wo-dimensional orientation distribution of linearly polarized light. A pola rization spatial filter, which can change the light polarization two-dimens ionally, is designed by considering the polarization distribution of the Fo urier transform of an image to be detected which is polarization-coded. The proposed technique shows a better capacity to discriminate gray-scale imag es than do the conventional matched altering techniques.