Polarization Enhanced Visual Surveillance Techniques

Visual surveillance relies on visible light to convey information about the environment. An important but less utilized characteristic of light in surveillance is its polarization due to the transverse wave nature of electromagnetic waves. Although the predominant natural light source, the sun light, appear to be unpolarized, the light that actually enters a surveillance camera often has biased polarization distribution due to scattering and reflection by the environment. These differently biased polarization patterns thus carry important information about the environment, such as material type, object shape...etc. With proper optical setup and computer vision analysis, polarization information can be captured and used to enhance traditional polarization-insensitive visual surveillance techniques. This work presents polarization based optical and computational techniques to improve target detection, to perform novel optical navigation, and to help resolve ambiguities in traditional visual sensors.