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Design of continuous and quantized amplitude holograms by generalized projections

William C. Catino, Joseph L. LoCicero and Henry Stark
Illinois Institute of Technology, Chicago, Illinois.


            The method of generalized projections is used to design pure-amplitude diffraction holograms that generate gray-scale images. Two algorithms are presented: the direct method nonlinearly constrains the hologram transmittance to the range of real values in [0,1]; the indirect method constrains the transmittance values to the real axis and linearly transforns the resulting values to the range [0,1]. Digital amplitude holograms were simulated by quantizing the amplitude holograms resulting from the indirect method. Performance is demonstrated with objective measures (error, efficiency, and variance) as well as with subjective comparison of images. Test images included a photographic quality image of Lena, a uniform intensity spot array, and a binary amplitude block text image.

W.C. Catino, J.L. LoCicero, and H. Stark, "Design of continuous and quantized amplitude holograms by generalized projections," J. Opt. Soc. Am. A. 15(1), 68-76 (January 1998)

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