Recognition of the Direction of New Apertures from Elongated Speckle Images

Long elongated speckle images were obtained using mechanical scanning of the static speckle pattern (Mu et al. in Opt Lett 10:375–377, 1985). The author presented a technique of spatially oriented speckle-screen encoding to improve the grating encoding technique for white-light image processing. Additionally, an artificial screen composed of small strips was photographed on a high-resolution film designed to obtain elongation ten times the average grain size of natural speckles (Barakat, Hamed, et al. in J Mod Opt 38:203–208, 1991). In a recent publication by the author (Hamed and Discrimination in Opt Eng 56:1–7, 2011), numerical elliptical apertures of small elliptic shapes were analyzed and the Fourier transform was used to obtain speckle images of diffusers modulated by these elliptic apertures. In this chapter, two sharp elliptical apertures were proposed, and corresponding elongated speckle images were obtained (Hamed, in Opt. Photon J. 3:250-258, 2013). Additionally, three different models are numerically fabricated, and the corresponding speckle images are computed and plotted. Finally, the reconstructed models of ellipses and the autocorrelation of these models are plotted.