Browsing by Author "Onural, L."
Now showing items 1-20 of 52
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3-D motion estimation and wireframe adaptation including photometric effects for model-based coding of facial image sequences
(IEEE, 1994-06)We propose a novel formulation where 3-D global and local motion estimation and the adaptation of a generic wireframe model to a particular speaker are considered simultaneously within an optical flow based framework ... -
3-D motion estimation of rigid objects for video coding applications using an improved iterative version of the E-matrix method
(Institute of Electrical and Electronics Engineers, 1998-02)As an alternative to current two-dimensional (2-D) motion models, a robust three-dimensional (3-D) motion estimation method is proposed to be utilized in object-based video coding applications. Since the popular E-matrix ... -
3D model compression using connectivity-guided adaptive wavelet transform built into 2D SPIHT
(Academic Press, 2010-01)Connectivity-Guided Adaptive Wavelet Transform based mesh compression framework is proposed. The transformation uses the connectivity information of the 3D model to exploit the inter-pixel correlations. Orthographic ... -
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A aurvey of signal processing problems and tools in holographic three-dimensional television
(Institute of Electrical and Electronics Engineers, 2007)Diffraction and holography are fertile areas for application of signal theory and processing. Recent work on 3DTV displays has posed particularly challenging signal processing problems. Various procedures to compute ... -
Calculation of the scalar diffraction field from curved surfaces by decomposing the three-dimensional field into a sum of Gaussian beams
(Optical Society of America, 2013)We present a local Gaussian beam decomposition method for calculating the scalar diffraction field due to a twodimensional field specified on a curved surface. We write the three-dimensional field as a sum of Gaussian beams ... -
Circular holographic video display system
(Optical Society of American (OSA), 2011)A circular holographic video display system reconstructs holographic video. Phase-only spatial light modulators are tiled in a circular configuration in order to increase the field of view. A beam-splitter is used to align ... -
A class of adaptive directional image smoothing filters
(Elsevier BV, 1996-12)The gray level distribution around a pixel of an image usually tends to be more coherent in some directions compared to other directions. The idea of adaptive directional filtering is to estimate the direction of higher ... -
A comparative study of light field representation and integral imaging
(Taylor and Francis, 2013-07-18)Light field representation is a model for three-dimensional (3D) image representation and integral imaging is an optical 3D imaging and representation method. A comparative investigation of light field representation and ... -
Convolution, filtering, and multiplexing in fractional Fourier domains and their relation to chirp and wavelet transforms
(, 1994)A concise introduction to the concept of fractional Fourier transforms is followed by a discussion of their relation to chirp and wavelet transforms. The notion of fractional Fourier domains is developed in conjunction ... -
Design and implementation of a general-purpose median filter unit in CMOS VLSI
(IEEE Solid-State Circuits Society, 1990)A general-purpose median filter unit configuration is proposed in the form of two single-chip median filters, one extensible and one real-time. The networks of the chips are pipelined and systolic at bit level and based ... -
Diffraction field computation from arbitrarily distributed data points in space
(Elsevier BV, 2007-02)Computation of the diffraction field from a given set of arbitrarily distributed data points in space is an important signal processing problem arising in digital holographic 3D displays. The field arising from such ... -
Diffraction from a wavelet point of view
(Optical Society of America, 1993-06-01)The system impulse response representing the Fresnel diffraction is shown to form a wavelet family of functions. The scale parameter of the wavelet family represents the depth (distance). This observation relates ... -
Digital decoding of in-line holograms
(SPIE, 1987)Digitally sampled in-line holograms may be linearly filtered to reconstruct a representation of the original object distribution, thereby decoding the information contained in the hologram. The decoding process is performed ... -
Digital holographic three-dimensional video displays
(IEEE, 2011-02-04)Holography aims to record and regenerate volume filling light fields to reproduce ghost-like 3-D images that are optically indistinguishable from their physical 3-D originals. Digital holographic video displays are ... -
Estimation of depth fields suitable for video compression based on 3-D structure and motion of objects
(Institute of Electrical and Electronics Engineers, 1998-06)Intensity prediction along motion trajectories removes temporal redundancy considerably in video compression algorithms. In three-dimensional (3-D) object-based video coding, both 3-D motion and depth values are required ... -
Evaluation of the validity of the scalar approximation in optical wave propagation using a systems approach and an accurate digital electromagnetic model
(Taylor and Francis Ltd., 2016)The cause and amount of error arising from the use of the scalar approximation in monochromatic optical wave propagation are discussed using a signals and systems formulation. Based on Gauss’s Law, the longitudinal component ... -
Exact analysis of the effects of sampling of the scalar diffraction field
(Optical Society of America, 2007)If the sampled diffraction pattern due to a planar object is used to reconstruct the object pattern by backpropagation, the obtained pattern is no longer the same as the original. The effect of such sampling on the ... -
Exact diffraction calculation from fields specified over arbitrary curved surfaces
(Elsevier, 2011-07-30)Calculation of the scalar diffraction field over the entire space from a given field over a surface is an important problem in computer generated holography. A straightforward approach to compute the diffraction field from ... -
Exact solution for scalar diffraction between tilted and translated planes using impulse functions over a surface
(Optical Society of America, 2011-02-04)The diffraction relation between a plane and another plane that is both tilted and translated with respect to the first one is revisited. The derivation of the result becomes easier when the impulse function over a surface ...
