title: Liquid crystal polarization-converting devices for edge and corner extractions of images using optical wavelet transforms.
abstract: Optical properties of radially polarized light generated by liquid crystal (LC) polarization-converting devices with two LC molecular orientations (+/-180 degrees and +/-90 degrees twist modes) are measured and the applicability to optical wavelet transforms (WTs) are discussed. It is found that the radially polarized lights in both the +/-180 degrees and +/-90 degrees twist modes can be regarded as wavelets. Based on the principle of WT, feature extractions of a simple binary image are carried out by applying the LC polarization-converting device to a shadow-casting system. Unique feature extraction properties of the shadow-casting system using the LC polarization-converting device and a LC microlens array are discussed. It is experimentally confirmed that edge and corner features are successfully extracted using the LC polarization-converting device with +/-180 degrees and +/-90 degrees twist modes, respectively.
authors.affiliation: Department of Electronics and Information Systems, Akita Prefectural University, Tsuchiya-Ebinokuchi, Honjo, Japan.
authors.forename: Michinori
authors.initials: M
authors.lastname: Honma
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Nose
authors.forename: Susumu
authors.initials: S
authors.lastname: Sato