Prof. Alexander A. Sawchuk Profile

Prof. Alexander A. Sawchuk

Professor Emeritus

SPIE Involvement:

Author

Publications (29)

Proceedings Article | 29 February 2008 Paper

Disparity manipulation for stereo images and video

Chiao Wang, Alexander Sawchuk

Proceedings Volume 6803, 68031E (2008) https://doi.org/10.1117/12.767702

KEYWORDS: Cameras, Video, Image processing, 3D modeling, Image segmentation, 3D image processing, Stereoscopic cameras, Algorithm development, Human-machine interfaces, Video processing

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Proceedings Article | 15 February 2008 Paper

Effects of stereoscopic displays and interaction devices on human motor behavior

Shih-Ching Yeh, Belinda Lange, C. Chang, Chiao Wang, Alexander Sawchuk, Albert Rizzo

Proceedings Volume 6804, 680405 (2008) https://doi.org/10.1117/12.767859

KEYWORDS: Optical tracking, Glasses, Camera shutters, Magnetic tracking, Autostereoscopic displays, Magnetism, Stereoscopic displays, Virtual reality, Phase measurement, Video

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Proceedings Article | 5 March 2007 Paper

A virtual reality oriented clinical experiment on post-stroke rehabilitation: performance and preference comparison among different stereoscopic displays

Shih-Ching Yeh, Albert Rizzo, Alexander Sawchuk

Proceedings Volume 6490, 64900A (2007) https://doi.org/10.1117/12.703739

KEYWORDS: Head-mounted displays, Seaborgium, Virtual reality, 3D displays, Stereoscopic displays, Eye, Head, Cameras, Camera shutters, Glasses

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Proceedings Article | 5 March 2007 Paper

Object-based disparity adjusting tool for stereo panorama

Chiao Wang, Chien-Yen Chang, Alexander Sawchuk

Proceedings Volume 6490, 64900D (2007) https://doi.org/10.1117/12.703215

KEYWORDS: Panoramic photography, Image segmentation, Image processing, Cameras, Image processing algorithms and systems, Image enhancement, Visualization, Image registration, Virtual reality, 3D displays

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Proceedings Article | 27 January 2006 Paper

Effects of gender, application, experience, and constraints on interaction performance using autostereoscopic displays

Z. Alpaslan, A. Sawchuk, A. Rizzo, S. Yeh

Proceedings Volume 6055, 60550D (2006) https://doi.org/10.1117/12.643125

KEYWORDS: Glasses, Autostereoscopic displays, 3D displays, Seaborgium, Camera shutters, CRTs, Virtual reality, Motion measurement, 3D imaging standards, Eye

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Proceedings Article | 27 January 2006 Paper

Adaptive parallax control for multi-view stereo panoramas

Chiao Wang, Alexander Sawchuk

Proceedings Volume 6055, 60550Z (2006) https://doi.org/10.1117/12.641508

KEYWORDS: Panoramic photography, 3D displays, Cameras, Image processing, Virtual reality, Imaging systems, Algorithm development, Image registration, Glasses, Adaptive control

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Proceedings Article | 20 January 2006 Paper

Variable threshold detection for 3D page-oriented optical data storage systems

Tawei Ho, Nopparit Intharasombat, Alexander Sawchuk

Proceedings Volume 6027, 60274L (2006) https://doi.org/10.1117/12.668418

KEYWORDS: 3D optical data storage, Point spread functions, Optical storage, Binary data, 3D image processing, 3D modeling, Imaging systems, Data analysis, Systems modeling, Data storage

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Proceedings Article | 20 January 2006 Paper

Iterative detection for imaging page-oriented optical data storage systems

Nopparit Intharasombat, Tawei Ho, Alexander Sawchuk

Proceedings Volume 6027, 60274K (2006) https://doi.org/10.1117/12.668417

KEYWORDS: Imaging systems, Data storage, Detection and tracking algorithms, Optical imaging, Computer programming, Optical storage, Modulation, Binary data, Systems modeling, Error control coding

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Proceedings Article | 22 March 2005 Paper

Quantitative comparison of interaction with shutter glasses and autostereoscopic displays

Zahir Alpaslan, Shih-Ching Yeh, Albert Rizzo, Alexander Sawchuk

Proceedings Volume 5664, (2005) https://doi.org/10.1117/12.589291

KEYWORDS: Glasses, 3D displays, Camera shutters, Autostereoscopic displays, 3D image processing, Image quality, 3D metrology, Optical spheres, Head, Data processing

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In this paper we describe experimental measurements and comparison of human interaction with three different types of stereo computer displays. We compare traditional shutter glasses-based viewing with three-dimensional (3D) autostereoscopic viewing on displays such as the Sharp LL-151-3D display and StereoGraphics SG 202 display. The method of interaction is a sphere-shaped “cyberprop” containing an Ascension Flock-of-Birds tracker that allows a user to manipulate objects by imparting the motion of the sphere to the virtual object. The tracking data is processed with OpenGL to manipulate objects in virtual 3D space, from which we synthesize two or more images as seen by virtual cameras observing them. We concentrate on the quantitative measurement and analysis of human performance for interactive object selection and manipulation tasks using standardized and scalable configurations of 3D block objects. The experiments use a series of progressively more complex block configurations that are rendered in stereo on various 3D displays. In general, performing the tasks using shutter glasses required less time as compared to using the autostereoscopic displays. While both male and female subjects performed almost equally fast with shutter glasses, male subjects performed better with the LL-151-3D display, while female subjects performed better with the SG202 display. Interestingly, users generally had a slightly higher efficiency in completing a task set using the two autostereoscopic displays as compared to the shutter glasses, although the differences for all users among the displays was relatively small. There was a preference for shutter glasses compared to autostereoscopic displays in the ease of performing tasks, and glasses were slightly preferred for overall image quality and stereo image quality. However, there was little difference in display preference in physical comfort and overall preference. We present some possible explanations of these results and point out the importance of the autostereoscopic "sweet spot" in relation to the user's head and body position.

Proceedings Article | 9 September 2004 Paper

Iterative detection for interpage interference in imaging page-oriented optical data storage

Nopparit Intharasombat, Tawei Ho, Alexander Sawchuk

Proceedings Volume 5380, (2004) https://doi.org/10.1117/12.557302

KEYWORDS: Optical storage, Binary data, Data storage, Optical imaging, Point spread functions, Detector arrays, Data processing, 3D modeling, Signal to noise ratio, Signal processing

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Proceedings Article | 9 September 2004 Paper

Least square equalization and variable thresholding for 3D page-oriented optical data storage systems

Tawei Ho, Nopparit Intharasombat, Alexander Sawchuk

Proceedings Volume 5380, (2004) https://doi.org/10.1117/12.556963

KEYWORDS: 3D optical data storage, Optical storage, 3D image processing, Point spread functions, Data storage, 3D modeling, Data modeling, Binary data, Matrices, Data analysis

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Proceedings Article | 21 May 2004 Paper

Three-dimensional interaction with autostereoscopic displays

Zahir Alpaslan, Alexander Sawchuk

Proceedings Volume 5291, (2004) https://doi.org/10.1117/12.524548

KEYWORDS: Cameras, Light sources, 3D displays, Autostereoscopic displays, 3D image processing, Video, Optical spheres, Imaging systems, Image resolution, LCDs

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Proceedings Article | 6 October 2003 Open Access

The role of the International Commission for Optics (ICO) in optics training and education

Alexander Sawchuk, Arthur Guenther

Proceedings Volume 9663, 966302 (2003) https://doi.org/10.1117/12.2208369

KEYWORDS: Photonics, Education and training, Signal processing, Image processing, Optical engineering

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Proceedings Article | 19 June 2003 Paper

Simulation and testing of an optical interconnection system using fiber image guides

Sunkwang Hong, Alexander Sawchuk

Proceedings Volume 4987, (2003) https://doi.org/10.1117/12.478316

KEYWORDS: Vertical cavity surface emitting lasers, Cladding, Waveguides, Wave propagation, Sensors, Optical alignment, Optical simulations, Optical interconnects, Detector arrays, Beam propagation method

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Proceedings Article | 30 May 2003 Paper

Flip-chip bonded optoelectronic integration based on ultrathin silicon (UTSi) CMOS

Sunkwang Hong, Tawei Ho, Liping Zhang, Alexander Sawchuk

Proceedings Volume 4997, (2003) https://doi.org/10.1117/12.476657

KEYWORDS: Vertical cavity surface emitting lasers, Receivers, Silicon, Telecommunications, Sapphire, Semiconductors, PIN photodiodes, Optical fibers, Optoelectronics, Sensors

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Proceedings Article | 10 January 2002 Paper

Multidimensional modulation codes and error correction for page-oriented optical data storage

Dhawat Pansatiankul, Alexander Sawchuk

Proceedings Volume 4342, (2002) https://doi.org/10.1117/12.453392

KEYWORDS: Modulation, Optical storage, Data storage, Imaging systems, Associative arrays, Mathematical modeling, Computer programming, Optical calibration, Digital recording, Detector arrays

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Proceedings Article | 4 January 2002 Paper

Low-complexity motion estimation for long-term memory motion compensation

Hyukjune Chung, Antonio Ortega, Alexander Sawchuk

Proceedings Volume 4671, (2002) https://doi.org/10.1117/12.453089

KEYWORDS: Motion estimation, Video, Computer simulations, Algorithms, Image processing, Distortion, Signal processing, Electrical engineering, Semiconductors, Visual communications

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Long term memory motion compensation (LTMC) is an approach to extend the temporal motion search range by using multiple decoded frames as reference frames. By employing multiple reference frames, LTMC reduces the residual frame energy significantly. However the computational complexity of motion estimation for LTMC increases significantly as well. Therefore reduction of the required computational complexity is one of the most challenging issues for LTMC. Also, if we locate motion search windows at fixed locations in a frame buffer for a given macro-block, it is highly possible that the oldest frames in a frame buffer do not contain matching blocks due to the reduced correlation between the current frame and the reference frames located further in the frame buffer. Therefore, if we can locate the motion search window at a good position adaptively in a frame buffer, we can enhance the gain performance of LTMS. In this paper, we propose a novel motion estimation algorithm for LTMC to reduce significantly the required computation complexity, and to enhance the performance of LTMC. For the proposed motion estimation algorithm, we introduce a directed search strategy. Also, we propose to employ hypothesis testing fast matching (HTFM) as a fast matching criterion. The goal of a directed search strategy is to let the location of the motion search windows change adaptively as the search proceeds to older frames in the frame buffer. The main benefit over standard, fixed window, approaches is that the algorithm can track larger motion and therefore, we can reduce the residual frame energy. In addition, because the directed search strategy keeps track of best matched blocks, we can reduce the computational complexity significantly by reducing the motion search window area in a frame buffer. Simulation results show that by employing the directed search with reduced motion search window, we can reduce the computational complexity approximately 30%-40%, and that by employing HTFM, we can reduce the computational complexity as additional 40%-50% as compared to the result of a full search algorithm which employs a non-directed search strategy for LTMC. The proposed algorithm provides particularly significant gains for video sequences which contain large motions. In the case of high motion sequences directed search also results in slight gains in PSNR over non-directed search.

Proceedings Article | 26 December 2001 Paper

Ultra-thin silicon (UTSi(R)) on insulator CMOS transceiver and time-division multiplexed switch chips for smart pixel integration

Liping Zhang, Alexander Sawchuk

Proceedings Volume 4435, (2001) https://doi.org/10.1117/12.451150

KEYWORDS: Vertical cavity surface emitting lasers, Transceivers, Silicon, Receivers, Switches, Clocks, Optoelectronics, Photonic integrated circuits, Sensors, Multiplexers

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Proceedings Article | 13 December 2001 Paper

Optical interconnection testbed using fiber image guides

Sunkwang Hong, Liping Zhang, Alexander Sawchuk

Proceedings Volume 4455, (2001) https://doi.org/10.1117/12.450430

KEYWORDS: Vertical cavity surface emitting lasers, Sensors, Optical interconnects, Field programmable gate arrays, Receivers, Cladding, Optical testing, Optoelectronics, Signal attenuation, 3D image processing

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Proceedings Article | 6 December 2001 Paper

Optical multi-token-ring networking using smart pixels with field programmable gate arrays (FPGAs)

Liping Zhang, Sunkwang Hong, Changki Min, Zahir Alpaslan, Alexander Sawchuk

Proceedings Volume 4470, (2001) https://doi.org/10.1117/12.449653

KEYWORDS: Clocks, Field programmable gate arrays, Vertical cavity surface emitting lasers, Optoelectronics, Signal detection, Photonic integrated circuits, Sensors, Signal processing, Receivers, Logic

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Proceedings Article | 24 May 2000 Paper

Parallel pipeline networking and signal processing with field-programmable gate arrays (FPGAs) and VCSEL-MSM smart pixels

C. Kuznia, Alexander Sawchuk, Liping Zhang, Bogdan Hoanca, Sunkwang Hong, Chris Min, Dhawat Pansatiankul, Zahir Alpaslan

Proceedings Volume 4089, (2000) https://doi.org/10.1117/12.386800

KEYWORDS: Field programmable gate arrays, Vertical cavity surface emitting lasers, Signal processing, Receivers, Signal detection, Interfaces, Logic, Image processing, Channel projecting optics, Sensors

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Proceedings Article | 19 July 1999 Paper

Modulator and VCSEL-MSM smart pixels for parallel pipeline networking and signal processing

C.-H. Chen, Bogdan Hoanca, C. Kuznia, Dhawat Pansatiankul, Liping Zhang, Alexander Sawchuk

Proceedings Volume 3749, (1999) https://doi.org/10.1117/12.354729

KEYWORDS: Modulators, Clocks, Signal processing, Laser applications, Free space optics, Optoelectronics, Data communications, Receivers, Vertical cavity surface emitting lasers, Image processing

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Proceedings Article | 13 April 1999 Paper

All-optical routing schemes for networks using wavelength-recognizing switches

Bogdan Hoanca, Serge Dubovitsky, Daniel Zhu, Alexander Sawchuk, William Steier, Paul Dapkus

Proceedings Volume 3632, (1999) https://doi.org/10.1117/12.344606

KEYWORDS: Switches, Switching, Waveguides, Control systems, Wavelength division multiplexing, Wave propagation, Optical amplifiers, Signal to noise ratio, Tunable lasers, Data modeling

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We have recently described a wavelength-recognizing switch (WRS) which we showed to be capable of truly all-optical routing. Although other authors had previously reported "all-optical" networks [1, 2, 3], the term has generally referred to all—optical data paths only. In such implementations only the data remains in optical format as it propagates along the network paths. Optical-to-electronic conversions are still allowed for what is termed "control signals," namely address bits and additional signaling entities, which are assumed to have lower speed than the data. In contrast, the WRS we presented has the capability to route data by interpreting the control signals in the optical domain, thus avoiding the overhead and the latency ofthe optic-to-electronic conversion. In a series of previous publications [4, 5] we demonstrated the experimental viability of the WRS and measured some of the relevant system parameters of the device. More recently, we published details on how the device could be used to build multistage all-optical self-routing networks. We also developed a simulation model and estimated the maximum number of stages that can be cascaded in such networks. The work presented in this paper carries the simulation results one step further, and investigates some of the possible topologies that can be used for WRS networks, as well as the system implications of these topologies. To facilitate a better understanding of the concepts presented, we briefly review the device functionality and the main experimental results that affect the system performance. We then show how to implement some of the building blocks we use in the self-routing topologies, and explain the equalization mechanism necessary for using WRS in multistage networks. We then compare the practical advantages of the topologies of interest and decide which topology is the most probable implementation. Finally we present details on a new generation of WRS, which is waveguide based, thus more easily fabricated and integrated with optical fiber systems

Proceedings Article | 22 May 1998 Paper

Architecture and optical system design for translucent smart pixel array (TRANSPAR) chips

C.-H. Chen, Bogdan Hoanca, C. Kuznia, Alexander Sawchuk, J.-M. Wu

Proceedings Volume 3490, (1998) https://doi.org/10.1117/12.308952

KEYWORDS: Signal detection, Optical design, Channel projecting optics, Transmitters, Clocks, Receivers, Modulators, Translucency, Objectives, Network architectures

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SPIE Journal Paper | 1 February 1996

All-optical invariant target recognition based on intensity-to-phase coding

Lev Sadovnik, Alexander Rizkin, Oleg Rashkovskiy, Alexander Sawchuk

OE, Vol. 35, Issue 02, (February 1996) https://doi.org/10.1117/12.10.1117/1.600899

KEYWORDS: Image processing, Diffraction, Phase shift keying, Distance measurement, Target recognition, Optically addressed spatial light modulators, Diffraction gratings, Photoresist materials, Phase modulation, Automatic target recognition

Proceedings Article | 8 July 1994 Paper

Inverse problem of dynamically variable halftoning

Lev Sadovnik, Alexander Sawchuk

Proceedings Volume 2241, (1994) https://doi.org/10.1117/12.179740

KEYWORDS: Inverse optics, Inverse problems, Diffraction, Binary data, Modulation, Diffraction gratings, Nonlinear optics, Optical signal processing, Graphic arts, Opacity

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Proceedings Article | 25 October 1993 Paper

Scale-, translation-, and rotation-invariant all-optical processor based on intensity-to-phase coding

Lev Sadovnik, Alexander Sawchuk, Thomas Lu, Andrew Kostrzewski

Proceedings Volume 1959, (1993) https://doi.org/10.1117/12.160299

KEYWORDS: Image processing, Diffraction, Optical pattern recognition, Halftones, Diffraction gratings, Phase shift keying, Modulation, Optically addressed spatial light modulators, Spatial light modulators, Binary data

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Proceedings Article | 12 July 1993 Paper

Space multiplexing in multistage optical interconnection networks

Andrew Miller, Lily Cheng, Alexander Sawchuk

Proceedings Volume 1806, (1993) https://doi.org/10.1117/12.147821

KEYWORDS: Multiplexing, Switches, Holograms, Optical components, Singular optics, Optical networks, Optoelectronics, Computing systems, Photonic integrated circuits, Optical interconnects

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Proceedings Article | 16 January 1990 Paper

Digital optical cellular computers

A. Sawchuk

Proceedings Volume 10257, 102570H (1990) https://doi.org/10.1117/12.2283581

KEYWORDS: Digital holography, Image processing, Computing systems, Optical computing, Computer architecture, Array processing, Binary data, Computer programming, Light, Sensors

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