Polarization camera sensors

Recently, polarization vision has been shown to simplify some important image understanding tasks that can be more difficult to perform with intensity vision alone. This, together with the more general capabilities of polarization vision for image understanding, motivates the building of camera sensors that automatically sense and process polarization information. Described in this paper are a variety of designs for polarization camera sensors that have been built to automatically sense partial linearly polarized light, and computationally process this sensed polarization information at pixel resolution to produce a visualization of reflected polarization from a scene, and/or a visualization of physical information in a scene directly related to sensed polarization. The three designs for polarization camera sensors presented utilize (i) serial acquisition of polarization components using liquid crystals, (ii) parallel acquisition of polarization components using a stereo pair of cameras and a polarizing beamsplitter, and (iii) a prototype photosensing chip with three scanlines, each scanline coated with a particular orientation of polarizing material. As the sensory input to polarization camera sensors subsumes that of standard intensity cameras, they can potentially significantly expand the application potential of computer vision. A number of images taken with polarization cameras are presented, showing potential applications to image understanding, object recognition, circuit board inspection and marine biology.