Recognition of Direction of New Apertures from the Elongated Speckle Images: Simulation

Abdallah Mohamed Hamed

Physics Department, Faculty of Science, Ain Shams University, Cairo, Egypt.

DOI: 10.4236/opj.2013.33040                

Abstract

In this paper, we present an elongated speckle images produced from diffusers using sharp elliptical apertures. The orientation of the elliptic aperture is recognized from the direction of the elongation in the speckle images. The aperture tilting out of the plane is investigated. Three models of elliptical apertures are considered and the corresponding speckle images are obtained. The 1st model is composed of two orthogonal ellipses or plus symbol pupil; the 2nd has four symmetric ellipses with an angle of 45° between each of them or in the form of a snow flake pupil and the 3rd model looks like an airplane. Also, the autocorrelation profiles of the speckle images corresponding to the diffused airplane are obtained from which the average speckle size is computed. Finally, the reconstructed images of the described elliptical models and its autocorrelation images, making use of Mat lab code, are obtained.

Keywords

Digital Imaging; Sharp Elliptical Apertures; Plus Symbol and Snow Flake Pupils

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	G. G. Mu, Z. Q. Wang, Q. Gong, Q. W. Song and F. X. Wu, “White-Light Image Processing Using Oriented Spec kle-Screen Encoding,” Optics Letters, Vol. 10, No. 8, 1985, pp. 375-377. doi:10.1364/OL.10.000375
[2]	N. Barakat, A. M. Hamed , H. El Ghandoor, K. El-Do himy, M. A. Fadly and O. A. Abdel Ghafar, “A Photo graphic Encoder Applied to an Optical Processor Using Speckle Techniques,” Journal of Modern Optics , Vol. 38, No. 1, 1991, pp. 203-208. doi:10.1080/09500349114550221
[3]	A. M. Hamed, “Discrimination between Speckle Images Using Deformed Apertures,” Optical Engineering, Vol. 56, No. 1, 2011, pp. 1-7.
[4]	P. Lehmann, S. Patzelt and A. Schone, “Surface Rough ness Measurement by Means of Polychromatic Speckle Elongation,” Applied Optics, Vol. 36, No. 10, 1997, pp. 2188-2197. doi:10.1364/AO.36.002188
[5]	P. Lehmann, “Aspect Ratio of Elongated Polychromatic Far-Field Speckles of Continuous and Discrete Spectral Distribution with Respect to Surface Roughness Charac terization,” Applied Optics, Vol. 41, No. 10, 2002, pp. 2008-2014. doi:10.1364/AO.41.002008
[6]	Z. H. Yuan, et al., “Comparison of Surface Roughness Measurement in Dichromatic Speckle Patterns with Auto correlation Method,” Advanced Materials Research, Vol. 189, 2011, pp. 680-683.
[7]	A. S. Kumar and R. M. Vasu, “Imaging with Oriented Photographic Diffusers,” Instrumentation and Services Unit, Indian Institute of Science, Bangalore, 2002.
[8]	H. Lin, “Speckle Mechanism in Holographic Optical Co herence Imaging,” Ph.D. Dissertation, University of Mis souri, Kansas City, 2009, pp. 57-58.
[9]	H. Lin and P. Yu, “Speckle Mechanism in Holographic Optical Imaging,” Optics Express, Vol. 15, No. 25, 2007, pp. 16322-16327. doi:10.1364/OE.15.016322
[10]	J. W. Goodmann, “Statistical Properties of Laser Speckle Patterns in Laser Speckle and Related Phenomena,” Sprin ger-Verlag, New York, 1984.
[11]	Y. Piederriere, J. Le Meur, J. Cariou, J. Abgrall and M. Blouch, “Particle Aggregation Monitoring by Speckle Size Measurement, Application to Blood Platelets Aggrega tion,” Optics Express, Vol. 12, No. 19, 2004, pp. 4596-4601. doi:10.1364/OPEX.12.004596
[12]	P. Lehmann, “Surface Roughness Measurement Based on the Intensity Correlation Function of Scattered Light un der Speckle Pattern Illumination,” Applied Optics, Vol. 38, No. 7, 1999, pp. 1144-1152. doi:10.1364/AO.38.001144
[13]	R. Berlasso, F. Perez Quintian, A. M. Rebollo, A. C. Raffo and G. N. Gaggioli, “Study of Speckle Size of Light Scattered from Cylindrical Rough Surfaces,” Applied Op tics, Vol. 39, No. 31 , 2000, pp.5811-5819. doi:10.1364/AO.39.005811
[14]	L. T. Alexander, E. J. Harvey and R. A. Weeks, “Average Speckle Size as a Function of Intensity Threshold Level: Comparison of Experimental Measurements with The ory,” Applied Optics, Vol. 33, No. 35, 1994, pp. 8240-8250. doi:10.1364/AO.33.008240
[15]	K. Matsushima, H. Schimmel and F. Wyrowski, “Fast Calculation Method for Optical Diffraction on Tilted Planes by Use of Angular Spectrum of Plane Waves,” Journal of the Optical Society of America, Vol. 20, No. 9, 2003, pp. 1755-1762. doi:10.1364/JOSAA.20.001755