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This paper describes the application of a laser diffraction technique to the study of electroconvection in nematic liquid crystal cells. It allows a real-time quantitative access to pattern wave lengths and amplitudes. The diffraction…

Strongly Correlated Electrons · Physics 2009-11-07 Th. John , U. Behn , R. Stannarius

Real world images often have highly imbalanced content density. Some areas are very uniform, e.g., large patches of blue sky, while other areas are scattered with many small objects. Yet, the commonly used successive grid downsampling…

Computer Vision and Pattern Recognition · Computer Science 2023-10-27 Chen Ziwen , Kaushik Patnaik , Shuangfei Zhai , Alvin Wan , Zhile Ren , Alex Schwing , Alex Colburn , Li Fuxin

We demonstrate a smart laser-diffraction analysis technique for particle mixture identification. We retrieve information about the size, geometry, and ratio concentration of two-component heterogeneous particle mixtures with an efficiency…

Image and Video Processing · Electrical Eng. & Systems 2022-02-03 Arturo Villegas , Mario A. Quiroz-Juarez , Alfred U'Ren , Juan P. Torres , Roberto de J. Leon-Montiel

Future large space telescopes will be equipped with adaptive optics (AO) to overcome wavefront aberrations and achieve high contrast for imaging faint astronomical objects, such as earth-like exoplanets and debris disks. In contrast to AO…

Instrumentation and Methods for Astrophysics · Physics 2020-01-07 He Sun , N. Jeremy Kasdin , Robert Vanderbei

Flow cytometry is a widespread and powerful technique, whose resolution is determined by its capacity to accurately distinguish fluorescently positive populations from negative ones. However, most informative results are discarded while…

The diffusion-based adversarial purification methods attempt to drown adversarial perturbations into a part of isotropic noise through the forward process, and then recover the clean images through the reverse process. Due to the lack of…

Computer Vision and Pattern Recognition · Computer Science 2025-12-09 Gaozheng Pei , Ke Ma , Yingfei Sun , Qianqian Xu , Qingming Huang

Visual object tracking is a challenging computer vision task with numerous real-world applications. Here we propose a simple but efficient Spectral Filter Tracking (SFT)method. To characterize rotational and translation invariance of…

Computer Vision and Pattern Recognition · Computer Science 2017-07-19 Zhen Cui , You yi Cai , Wen ming Zheng , Jian Yang

Boundary detection of irregular and translucent objects is an important problem with applications in medical imaging, environmental monitoring and manufacturing, where many of these applications are plagued with scarce labeled data and low…

Computer Vision and Pattern Recognition · Computer Science 2026-04-14 Fei Yu Guan , Ian Keefe , Sophie Wilkinson , Daniel D. B. Perrakis , Steven Waslander

Dense image prediction tasks demand features with strong category information and precise spatial boundary details at high resolution. To achieve this, modern hierarchical models often utilize feature fusion, directly adding upsampled…

Computer Vision and Pattern Recognition · Computer Science 2024-08-26 Linwei Chen , Ying Fu , Lin Gu , Chenggang Yan , Tatsuya Harada , Gao Huang

In this paper, we study the problem of reverse image filtering. An image filter denoted g(.), which is available as a black box, produces an observation b = g(x) when provided with an input x. The problem is to estimate the original input…

Image and Video Processing · Electrical Eng. & Systems 2022-06-22 Fernando Galetto , Guang Deng

To leverage deep learning for image aesthetics assessment, one critical but unsolved issue is how to seamlessly incorporate the information of image aspect ratios to learn more robust models. In this paper, an adaptive fractional dilated…

Computer Vision and Pattern Recognition · Computer Science 2020-04-08 Qiuyu Chen , Wei Zhang , Ning Zhou , Peng Lei , Yi Xu , Yu Zheng , Jianping Fan

This paper proposes a non-computational method of counteracting the effect of image degradation introduced by the diffraction phenomenon in lensless microscopy. All the optical images (whether focused by lenses or not) are diffraction…

Optics · Physics 2021-04-08 Sanjeev Kumar , Manjunatha Mahadevappa , Pranab Kumar Dutta

This paper demonstrates a method of interpreting the mechanism of aberration of optical systems based on non-Fourier transform optical transfer function (OTF). According to the parameters of object plane cosine fringe, we obtain the…

Optics · Physics 2018-12-27 Yu Bai , Jiaqi Chen , Fangjie Li , Zhenming Zhao

Real-image super-resolution (Real-ISR) seeks to recover HR images from LR inputs with mixed, unknown degradations. While diffusion models surpass GANs in perceptual quality, they under-reconstruct high-frequency (HF) details due to a…

Computer Vision and Pattern Recognition · Computer Science 2026-04-14 Seungho Choi , Jeahun Sung , Jihyong Oh

Coherent Diffractive Imaging is a lensless technique that allows imaging of matter at a spatial resolution not limited by lens aberrations. This technique exploits the measured diffraction pattern of a coherent beam scattered by periodic…

Computational Physics · Physics 2025-08-27 Alessandro Colombo , Davide Emilio Galli , Liberato De Caro , Francesco Scattarella , Elvio Carlino

Context. Narrow-band interference filters can be tuned toward shorter wavelengths by tilting them from the perpendicular to the optical axis. This can be used as a cheap alternative to real tunable filters, such as Fabry-P\'erot…

Instrumentation and Methods for Astrophysics · Physics 2011-08-31 Mats G. Löfdahl , Vasco M. J. Henriques , Dan Kiselman

For optical coherence tomography angiography (OCTA) images, a limited scanning rate leads to a trade-off between field-of-view (FOV) and imaging resolution. Although larger FOV images may reveal more parafoveal vascular lesions, their…

Image and Video Processing · Electrical Eng. & Systems 2024-12-06 Weiwen Zhang , Dawei Yang , Haoxuan Che , An Ran Ran , Carol Y. Cheung , Hao Chen

The parametric fluorescence from a nonlinear crystal forms a conical radiation pattern. We measure the angular and spectral distributions of parametric fluorescence in a beta-barium borate crystal pumped by a 405-nm diode laser employing…

Optics · Physics 2013-10-04 Feng-kuo Hsu , Chih-Wei Lai

The displacement field in highly non uniformly strained crystals is obtained by addition of constraints to an iterative phase retrieval algorithm. These constraints include direct space density uniformity and also constraints to the sign…

Materials Science · Physics 2009-11-11 A. A. Minkevich , M. Gailhanou , J. -S. Micha , B. Charlet , V. Chamard , O. Thomas

Light field imaging extends the traditional photography by capturing both spatial and angular distribution of light, which enables new capabilities, including post-capture refocusing, post-capture aperture control, and depth estimation from…

Computer Vision and Pattern Recognition · Computer Science 2018-03-14 M. Shahzeb Khan Gul , Bahadir K. Gunturk