Browsing by Author "Kutay, M. A."
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An adaptive speckle suppression filter for medical ultrasound imaging
Karaman, M.; Kutay, M. A.; Bozdagi, G. (Institute of Electrical and Electronics Engineers, 199506)An adaptive smoothing technique for speckle suppression in medical Bscan ultrasonic imaging is presented. The technique is based on filtering with appropriately shaped and sized local kernels. For each image pixel, a ... 
Continuous and discrete fractional fourier domain decomposition
Yetik, İ. Şamil; Kutay, M. A.; Özaktaş, H.; Özaktaş, Haldun M. (IEEE, 2000)We introduce the fractional Fourier domain decomposition for continuous and discrete signals and systems. A procedure called pruning, analogous to truncation of the singularvalue decomposition, underlies a number of ... 
Digital computation of linear canonical transforms
Koç A.; Özaktaş, Haldun M.; Candan, C.; Kutay, M. A. (Institute of Electrical and Electronics Engineers, 2008)We deal with the problem of efficient and accurate digital computation of the samples of the linear canonical transform (LCT) of a function, from the samples of the original function. Two approaches are presented and ... 
Digital computation of the fractional Fourier transform
Özaktaş, Haldun M.; Arıkan, Orhan; Kutay, M. A.; Bozdağı, G. (Institute of Electrical and Electronics Engineers, 199609)An algorithm for efficient and accurate computation of the fractional Fourier transform is given. For signals with timebandwidth product N, the presented algorithm computes the fractional transform in O(NlogN) time. A ... 
The discrete fractional Fourier transform
Candan, C.; Kutay, M. A.; Özaktaş, Haldun M. (IEEE, 200005)We propose and consolidate a definition of the discrete fractional Fourier transform that generalizes the discrete Fourier transform (DFT) in the same sense that the continuous fractional Fourier transform generalizes ... 
The discrete harmonic oscillator, Harper's equation, and the discrete fractional Fourier transform
Barker, L.; Candan, C.; Hakioğlu, T.; Kutay, M. A.; Özaktaş, Haldun M. (Institute of Physics Publishing, 2000)Certain solutions to Harper's equation are discrete analogues of (and approximations to) the HermiteGaussian functions. They are the energy eigenfunctions of a discrete algebraic analogue of the harmonic oscillator, and ... 
Effect of fractional Fourier transformation on timefrequency distributions belonging to the Cohen class
Özaktaş, Haldun M.; Erkaya, N.; Kutay, M. A. (Institute of Electrical and Electronics Engineers, 199602)We consider the Cohen (1989) class of timefrequency distributions, which can be obtained from the Wigner distribution by convolving it with a kernel characterizing that distribution. We show that the timefrequency ... 
Efficient computation of quadraticphase integrals in optics
Özaktaş, H. M.; Koç, A.; Sarı, I.; Kutay, M. A. (Optical Society of America, 2006)Received June 29, 2005; revised manuscript received August 22, 2005; accepted September 12, 2005 We present a fast N log N time algorithm for computing quadraticphase integrals. This threeparameter class of integrals ... 
Fast algorithms for digital computation of linear canonical transforms
Koç, A.; Oktem, F. S.; Özaktaş, Haldun M.; Kutay, M. A. (Springer, New York, 2016)Fast and accurate algorithms for digital computation of linear canonical transforms (LCTs) are discussed. Direct numerical integration takes O.N2/ time, where N is the number of samples. Designing fast and accurate ... 
The fractional Fourier domain decomposition
Kutay, M. A.; Özaktaş, H.; Özaktaş, Haldun M.; Arıkan, Orhan (Elsevier, 1999)We introduce the fractional Fourier domain decomposition. A procedure called pruning, analogous to truncation of the singularvalue decomposition, underlies a number of potential applications, among which we discuss fast ... 
The fractional fourier transform
Özaktas, Haldun M.; Kutay, M. A. (IEEE, 2001)A brief introduction to the fractional Fourier transform and its properties is given. Its relation to phasespace representations (time or spacefrequency representations) and the concept of fractional Fourier domains are ... 
Fractional fourier transform
Özaktaş, Haldun M.; Kutay, M. A.; Candan, Ç. (CRC Press, 2010) 
The Fractional Fourier transform and harmonic oscillation
Kutay, M. A.; Özaktaş, Haldun M. (Springer, 2002)The athorder fractional Fourier transform is a generalization of the ordinary Fourier transform such that the zerothorder fractional Fourier transform operation is equal to the identity operation and the firstorder ... 
The fractional fourier transform and its applications to image representation and beamforming
Yetik, I. Ş; Kutay, M. A.; Özaktaş, Haldun. M. (ASME, 200309)The ath order fractional Fourier transform operator is the ath power of the ordinary Fourier transform operator. We provide a brief introduction to the fractional Fourier transform, discuss some of its more important ... 
Image representation and compression with the fractional Fourier transform
Yetik, İ. Ş.; Kutay, M. A.; Özaktaş, Haldun M. (Elsevier, 20010401)We discuss the application of fractional Fourier transformbased filtering configurations to image representation and compression. An image can be approximately represented (and stored or transmitted) as the coefficients ... 
Improved acoustics signals discrimination using fractional Fourier transform based phasespace representations
Zalevsky, Z.; Mendlovic, D.; Kutay, M. A.; Özaktaş, Haldun M.; Solomon, J. (Elsevier, 20010401)In this communication we propose performing twodimensional correlation operation between phasespace representations based on the fractional Fourier transform, instead of correlating the signals themselves. A numerical ... 
Linear algebraic theory of partial coherence: continuous fields and measures of partial coherence
Özaktaş, Haldun M.; Gulcu, T. C.; Kutay, M. A. (Optical Society of America, 2016)This work presents a linear algebraic theory of partial coherence for optical fields of continuous variables. This approach facilitates use of linear algebraic techniques and makes it possible to precisely define the ... 
Linear algebraic theory of partial coherence: discrete fields and measures of partial coherence
Özaktaş, Haldun M.; Yüksel, S.; Kutay, M. A. (SPIE, 200308)We present a linear algebraic theory of partial coherence which allows precise mathematical definitions of concepts such as coherence and incoherence. This not only provides new perspectives and insights, but also allows ... 
Linear algebraic theory of partial coherence: discrete fields and measures of partial coherence
Özaktaş, Haldun M.; Yuksel, S.; Kutay, M. A. (OSA Publishing, 2002)A linear algebraic theory of partial coherence is presented that allows precise mathematical definitions of concepts such as coherence and incoherence. This not only provides new perspectives and insights but also allows ... 
Nonseperable twodimensional fractional Fourier transform
Sahin, A.; Kutay, M. A.; Özaktaş, Haldun M. (Optical Society of America, 1998)Previous generalizations of the fractional Fourier transform to two dimensions assumed separable kernels. We present a nonseparable definition for the twodimensional fractional Fourier transform that includes the separable ...