Diffractive optical Hough transform implemented with phase singularities.
The conventional Hough transform is implemented with a computer-generated hologram. The transmission function of the computer-generated hologram is computed with an extension of Bryngdahl's technique, which incorporates branch-point phase singularities. With this implementation it is shown that the branch-point technique can be used to implement point transforms successfully with an implicit transformation equation such as the Hough transform. This is done first by expression of the implicit transform in terms of several explicit transforms. After computation of the complex-valued transmission functions of the explicit transform, the functions are added together to form the transmission function for the implicit transform. Results are obtained by computation of Fresnel diffraction patterns of the Hough-transform computer-generated hologram, illuminated by different input images.
Roux
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