Li F.,Aptina |
Pelz J.B.,Rochester Institute of Technology |
Daly S.J.,Sharp Labs Of America
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010
Smooth pursuit eye movements align the retina with moving targets, ideally stabilizing the retinal image. At a steadystate, eye movements typically reach an approximately constant velocity which depends on, and is usually lower than the target velocity. Experiment 1 investigated the effect of target size and velocity on smooth pursuit induced by realistic images (color photographs of an apple and flower subtending 2° and 17°, respectively), in comparison with a small dot subtending a fraction of a degree. The extended stimuli were found to enhance smooth pursuit gain. Experiment 2 examined the absolute velocity limit of smooth pursuit elicited by the small dot and the effect of the extended targets on the velocity limit. The eye velocity for tracking the dot was found to be saturated at about 63 deg/sec while the saturation velocity occurred at higher velocities for the extended images. The difference in gain due to target size was significant between dot and the two extended stimuli, while no statistical difference exists between an apple and flower stimuli of wider angular extent. Detailed knowledge of the smooth pursuit eye movements is important for several areas of electronic imaging, in particular, assessing perceived motion blur of displayed objects. © 2010 Copyright SPIE - The International Society for Optical Engineering.
Ma Z.,New York University |
Segall A.,Sharp Labs Of America
Proceedings - International Conference on Image Processing, ICIP | Year: 2011
In this paper, we propose a novel hybrid frame buffer compression algorithm to reduce the memory bandwidth for low-power video coding. In our work, we first decompose the full-resolution image into low resolution (LR) and high resolution (HR) components. We then calculate the HR residual by taking the difference between original HR pixel and an estimate derived from surrounding LR pixels. Finally, we use absolute moment block truncation coding to quantize and compress the LR pixel and HR residual data so as to reduce the memory bandwidth. We integrate our approach into the JCT-VC reference software for High Efficiency Video Coding (HEVC). Results show negligible impact on coding efficiency with significant memory bandwidth reduction. Specifically, we observe a bit rate increase of 0.38% and 1% with 21% and 31% memory bandwidth reduction, respectively. © 2011 IEEE.
Van Beek P.,Sharp Labs of America |
Yang J.,University of Illinois at Chicago |
Yamamotoc S.,Sharp Corporation |
Ueda Y.,Sharp Corporation
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010
In this paper, we investigate the use of the non-local means (NLM) denoising approach in the context of image deblurring and restoration. We propose a novel deblurring approach that utilizes a non-local regularization constraint. Our interest in the NLM principle is its potential to suppress noise while effectively preserving edges and texture detail. Our approach leads to an iterative cost function minimization algorithm, similar to common deblurring methods, but incorporating update terms due to the non-local regularization constraint. The dataadaptive noise suppression weights in the regularization term are updated and improved at each iteration, based on the partially denoised and deblurred result. We compare our proposed algorithm to conventional deblurring methods, including deblurring with total variation (TV) regularization. We also compare our algorithm to combinations of the NLM-based filter followed by conventional deblurring methods. Our initial experimental results demonstrate that the use of NLM-based filtering and regularization seems beneficial in the context of image deblurring, reducing the risk of over-smoothing or suppression of texture detail, while suppressing noise. Furthermore, the proposed deblurring algorithm with non-local regularization outperforms other methods, such as deblurring with TV regularization or separate NLM-based denoising followed by deblurring. © 2010 SPIE.
Kim S.-H.,Sharp Labs of America |
Zhao J.,Sharp Labs of America |
Misra K.,Sharp Labs of America |
Segall A.,Sharp Labs of America
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015
Displays capable of showing a greater range of luminance values can render content containing high dynamic range information in a way such that the viewers have a more immersive experience. This paper introduces the design aspects of a high dynamic range (HDR) system, and examines the performance of the HDR processing chain in terms of compression efficiency. Specifically it examines the relation between recently introduced Society of Motion Picture and Television Engineers (SMPTE) ST 2084 transfer function and the High Efficiency Video Coding (HEVC) standard. SMPTE ST 2084 is designed to cover the full range of an HDR signal from 0 to 10,000 nits, however in many situations the valid signal range of actual video might be smaller than SMPTE ST 2084 supported range. The above restricted signal range results in restricted range of code values for input video data and adversely impacts compression efficiency. In this paper, we propose a code value remapping method that extends the restricted range code values into the full range code values so that the existing standards such as HEVC may better compress the video content. The paper also identifies related non-normative encoder-only changes that are required for remapping method for a fair comparison with anchor. Results are presented comparing the efficiency of the current approach versus the proposed remapping method for HM-16.2. © 2015 SPIE.
Seo H.-J.,Sharp Labs of America |
Milanfar P.,University of California at Santa Cruz
Eurasip Journal on Advances in Signal Processing | Year: 2012
A practical problem addressed recently in computational photography is that of producing a good picture of a poorly lit scene. The consensus approach for solving this problem involves capturing two images and merging them. In particular, using a flash produces one (typically high signal-to-noise ratio [SNR]) image and turning off the flash produces a second (typically low SNR) image. In this article, we present a novel approach for merging two such images. Our method is a generalization of the guided filter approach of He et al., significantly improving its performance. In particular, we analyze the spectral behavior of the guided filter kernel using a matrix formulation, and introduce a novel iterative application of the guided filter. These iterations consist of two parts: a nonlinear anisotropic diffusion of the noisier image, and a nonlinear reaction-diffusion (residual) iteration of the less noisy one. The results of these two processes are combined in an unsupervised manner. We demonstrate that the proposed approach outperforms state-of-the-art methods for both flash/no-flash denoising, and deblurring. © 2012 Seo and Milanfar.
Jagodic R.,University of Illinois at Chicago |
Renambot L.,University of Illinois at Chicago |
Johnson A.,University of Illinois at Chicago |
Leigh J.,University of Illinois at Chicago |
Deshpande S.,Sharp Labs of America
Future Generation Computer Systems | Year: 2011
As the amount and the resolution of collected scientific data increase, scientists are realizing the potential benefits that large high-resolution displays can have in assimilating this incoming data. Often this data has to be processed on powerful remote computing and storage resources, converted to high-resolution digital media and yet visualized on a local tiled-display. This is the basic premise behind the OptIPuter model. While the streaming middleware to enable this kind of work exists and the optical networking infrastructure is becoming more widely available, enabling multi-user interaction in such environments is still a challenge. In this paper, we present an interaction system we developed to support collaborative work on large high-resolution displays using multiple interaction devices and scalable, distributed user interface widgets. This system allows multiple users to simultaneously interact with local or remote data, media and applications, through a variety of physical interaction devices on large high-resolution displays. Finally, we present our experiences with using the system over the past two years. Most importantly, having an actual working system based on the OptIPuter model allows us to focus our research efforts to better understand how to make such high-resolution environments more user-friendly and usable in true real-world collaborative scenarios as opposed to constrained laboratory settings. © 2010 Elsevier B.V. All rights reserved.
Miles A.,University of Arizona |
Cocilovo B.,University of Arizona |
Wheelwright B.,University of Arizona |
Pan W.,Sharp Labs of America |
And 2 more authors.
Applied Optics | Year: 2016
We have developed an approach for designing a dichroic coating to optimize performance of current-matched multijunction photovoltaic cells while diverting unused light. By matching the spectral responses of the photovoltaic cells and currentmatching them, substantial improvement to system efficiencies is shown to be possible. A design for use in a concentrating hybrid solar collector was produced by this approach, and is presented. Materials selection, design methodology, and tilt behavior on a curved substrate are discussed. © 2016 Optical Society of America.
Pan H.,Sharp Labs Of America |
Yuan C.,Sharp Labs Of America |
Daly S.,Sharp Labs Of America
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011
One of the key issues associated with 3D TVs is the tradeoff between comfort and 3D visual impact. Big disparity is often preferred for strong visual impact but often lead to viewer discomfort depending on viewer's condition, display size and viewing distances. The algorithm proposed in this paper is to provide viewers a tool to adjust disparity according to the environment, contents and their preference in order to have more comfortable and higher quality 3D experiences. More specifically, given a planar stereoscopic display, the algorithm takes in a stereoscopic image pair that causes viewing discomfort/fatigue, and outputs a modified stereoscopic pair that causes less or no viewing discomfort/fatigue. The algorithm fulfills the functions of disparity estimation, occlusion detection, disparity adjustment and view synthesis. A novel pixel weighting mechanism in regularized-block-matching based disparity estimation helps improve the robustness, accuracy and speed of matching. Occlusion detection uses multiple cues in addition to matching errors to improve the accuracy. An accommodation/vergence mismatch visual model is used in disparity adjustment to predict discomfort/fatigue from the disparity information, the viewing conditions and display characteristics. The hole filling is in the disparity map of the new view instead of the new view itself to reduce the blurriness. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
Segall A.,Sharp Labs of America |
Zhao J.,Sharp Labs of America |
Yamamoto T.,Sharp Corporation
28th Picture Coding Symposium, PCS 2010 | Year: 2010
In this paper, we propose an intra-prediction system that is both parallel friendly and with high coding efficiency. This is achieved by combining a novel prediction strategy that reduces serial dependencies and a novel, multi-directional and adaptive prediction system. The resulting technique is compared with state-of-the-art ITU-T H.264/MPEG-4 AVC. We observe a 2x and 8x increase in parallelism for 8×8 and 4×4 partitions, respectively, and an average rate increase of less than 0.08% for predictive coding scenarios. © 2010 IEEE.
Valdivia A.,Oregon State University |
Tweet D.J.,Sharp Labs of America |
Conley J.F.,Oregon State University
Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films | Year: 2016
Low temperature atomic layer deposition (ALD) of monolayer to few layer MoS2 uniformly across 150 mm diameter SiO2/Si and quartz substrates is demonstrated. Purge separated cycles of MoCl5 and H2S precursors are used at reactor temperatures of up to 475 °C. Raman scattering studies show clearly the in-plane (E1 2g) and out-of-plane (A1g) modes of MoS2. The separation of the E1 2g and A1g peaks is a function of the number of ALD cycles, shifting closer together with fewer layers. X-ray photoelectron spectroscopy indicates that stoichiometry is improved by postdeposition annealing in a sulfur ambient. High resolution transmission electron microscopy confirms the atomic spacing of monolayer MoS2 thin films. © 2016 American Vacuum Society.