Positional, rotational and scale invariant optical correlation method and apparatus
Rotationally independent optical correlation for position determination
Optical detection of geometric configurations
Holographic signature processor
ApplicationNo. 481446 filed on 02/16/1990
US Classes:359/11, Spatial, phase or amplitude modulation349/17, Computational system employing liquid crystal element (neural network, correlation device, optical computer)359/19, Lens359/29, Fourier transform holography359/256, With birefringent element359/561, For correlation382/210Spatial filtering (e.g., holography)
ExaminersPrimary: Arnold, Bruce Y.
Assistant: Shafer, Ricky D.
Attorney, Agent or Firm
International ClassesG02B 005/30
AbstractAn image enhanced optical correlator system providing for optical preprocessing of an input image prior to processing thereof in an optical correlator. The optical preprocessing is provided to enhance the image and/or image related characteristics such that the probability of detection of prescribed targets therein in the optical correlator is increased. In the system, an input image beam is split into orthogonally polarized image inputs, processed to enhance targets therein, and then the algebraic result (addition and/or subtraction) thereof is processed through an optical correlator. Techniques are used in the feedback systems to enhance the output plane correlation signal detection by an adjustment in phase, spatial frequency filtering and/or threshold setting optimization.