Browsing by Author "Onural, L."
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Extensions to common laplace and fourier transforms
Onural, L.; Erden, M. F.; Özaktaş, Haldun M. (Institute of Electrical and Electronics Engineers, 199711)The extended versions of common Laplace and Fourier transforms are given. This is achieved by defining a new function fe(p), p 2 C related to the function to be transformed f(t), t 2 R. Then fe(p) is transformed by an ... 
Family of scaling chirp functions, diffraction, and holography
Onural, L.; Kocatepe, M. (Institute of Electrical and Electronics Engineers, 1995)It is observed that diffraction is a convolution operation with a chirp kernel whose argument is scaled. Family of functions obtained from a prototype by shifting and argument scaling form the essential ground for wavelet ... 
Fullcomplex amplitude modulation with binary spatial light modulators
Ulusoy, E.; Onural, L.; Özaktaş, Haldun M. (Optical Society of America, 20111019)Imperfections and nonrobust behavior of practical multilevel spatial light modulators (SLMs) degrade the performance of many proposed fullcomplex amplitude modulation schemes. We consider the use of more robust binary ... 
Generating connected textured fractal patterns using Markov random fields
Onural, L. (Institute of Electrical and Electronics Engineers, 1991)An algorithm that yields textured and connected binary fractals is presented. The texture is imposed by modeling the fractal as a Markov random field (MRF) at every resolution level. The model size and the parameters specify ... 
Gibbs random field model based weight selection for the 2D adaptive weighted median filter
Onural, L.; Alp, M. B.; Gürelli, M. I. (IEEE, 1994)A generalized filtering method based on the minimization of the energy of the Gibbs model is described. The wellknown linear and median filters are all special cases of this method. It is shown that, with the selection ... 
Graphics processing unit accelerated computation of digital holograms
Kang, H.; Yaraş, F.; Onural, L. (Optical Society of America, 2009)An approximation for fast digital hologram generation is implemented on a central processing unit (CPU), a graphics processing unit (GPU), and a multiGPU computational platform. The computational performance of the method ... 
Hologram synthesis for photorealistic reconstruction
Janda, M.; Hanák, I.; Onural, L. (Optical Society of America, 2008)Computation of diffraction patterns, and thus holograms, of scenes with photorealistic properties is a highly complicated and demanding process. An algorithm, based primarily on computer graphics methods, for computing ... 
Image sequence analysis for emerging interactive multimedia servicesthe European COST 211 framework
Alatan, A. A.; Onural, L.; Wollborn, M.; Mech, R.; Tuncel, E.; Sikora, T. (Institute of Electrical and Electronics Engineers, 199811)Flexibility and efficiency of coding, content extraction, and contentbased search are key research topics in the field of interactive multimedia. Ongoing ISO MPEG4 and MPEG7 activities are targeting standardization to ... 
An improvement to MBASIC algorithm for 3D motion and depth estimation
Bozdağı, G.; Tekalp, A. M.; Onural, L. (IEEE, 1994)In modelbased coding of facial images, the accuracy of motion and depth parameter estimates strongly affects the coding efficiency. MBASIC is a simple and effective iterative algorithm (recently proposed by Aizawa et al.) ... 
Impulse functions over curves and surfaces and their applications to diffraction
Onural, L. (Elsevier Science & Technology, 20061001)An explicit preferred definition of impulse functions (Dirac delta functions) over lowerdimensional manifolds in RN is given in such a way to assure uniform concentration per geometric unit of the manifold. Some related ... 
Integral imaging based 3D display of holographic data
Yontem, A. O.; Onural, L. (Optical Society of America, 2012)We propose a method and present applications of this method that converts a diffraction pattern into an elemental image set in order to display them on an integral imaging based display setup. We generate elemental images ... 
Integral imaging using phaseonly LCoS spatial light modulators as Fresnel lenslet arrays
Ÿontem, A. O.; Onural, L. (Optical Society of Amercia, 20111027)We present a digital integral imaging system. A Fresnel lenslet array pattern is written on a phaseonly LCoS spatial light modulator device (SLM) to replace the regular analog lenslet array in a conventional integral ... 
Introduction to the issue on emerging techniques in 3D
Alatan, A. A.; Ostermann, J.; Onural, L.; AlRegib, G.; Mattoccia, S.; Yuan, C. (IEEE, 2012)The fifteen papers in this special section that focus on three dimensional content (3D), with particular emphasis on the fusion of conventional camera outputs with those captured by other modalities, such as active sensors, ... 
Introduction to the special section on 3DTV
Onural, L.; Sikora, T. (Institute of Electrical and Electronics Engineers, 2007)The set of six papers that we invited to this part of the Special Section present extensive reviews of the stateoftheart in functional building blocks of 3DTV systems. 
Message from the chairs
Güdükbay, Uğur; Onural, L. (2011) 
New highresolution display device for holographic threedimensional video: principles and simulations
Onural, L.; Bozdağı, G.; Atalar, Abdullah (SPIE, 1994)A new acoustooptical holographic display device, which is expected to solve the display resolution and refresh problems that are common to available holographic displays, is proposed. The device is based on the ... 
New radix2based algorithm for fast median filtering
Karaman, M.; Onural, L. (IEEE, 1989)A fast radi2based median filtering algorithm is proposed. The median is determined bitbybit successively by eliminating the samples whose previous bits are different to that of the median. The intermediate computations ... 
On a parameter estimation method for GibbsMarkov random fields
Gürelli, M. I.; Onural, L. (IEEE, 1994)This correspondence is about a GibbsMarkov random field (GMRF) parameter estimation technique proposed by Derin and Elliott. We will refer to this technique as the histogramming (H) method. First, the relation of the H ... 
Perspective projections in the spacefrequency plane and fractional Fourier transforms
Yetik, I. S.; Özaktaş, Haldun M.; Barshan, B.; Onural, L. (OSA Publishing, 20000706)Perspective projections in the spacefrequency plane are analyzed, and it is shown that under certain conditions they can he approximately modeled in terms of the fractional Fourier transform, The region of validity of the ... 
Projectionslice theorem as a tool for mathematical representation of diffraction
Onural, L. (Institute of Electrical and Electronics Engineers, 2007)Although the impulse (Dirac delta) function has been widely used as a tool in signal processing, its more complicated counterpart, the impulse function over higher dimensional manifolds in ℝN, did not get such a widespread ...