Results 21 to 30 of about 52,858 (287)

Spatio-temporal Speckle Reduction in Ultrasound Sequences [PDF]

Inverse Problems & Imaging, 2008
In this paper we will be concerned with speckle removal in ultrasound images. To this end, we introduce a new spatio-temporal de-noising method based on a variational formulation. The regularization relies on a non parametric image model that describes the observed image structure and express inter-dependencies between pixels in space and time ...
Azzabou, Noura, Paragios, Nikos
openaire   +4 more sources

Multi-frame speckle reduction in OCT using supercontinuum pumped by noise-like pulses [PDF]

Journal of Innovative Optical Health Sciences, 2019
In most coherent imaging modality, speckle noise is a major cause that blurs the boundary of tissues and degrades the image contrast. By utilizing the unique properties of supercontinuum (SC) generated by noise-like pulses (NLPs) and a simple multi-frame
Chengming Wang, Yi-Jing You, Shengnan Ai, Wenxin Zhang, Wenchao Liao, Xiao Zhang, Juicheng Hsieh, Ning Zhang, Bihua Tang, Ci-Ling Pan, Ping Xue   +10 more
doaj   +1 more source

Nanolasers with Feedback as Low-Coherence Illumination Sources for Speckle-Free Imaging: A Numerical Analysis of the Superthermal Emission Regime

Nanomaterials, 2021
Lasers distinguish themselves for the high coherence and high brightness of their radiation, features which have been exploited both in fundamental research and a broad range of technologies.
Tao Wang, Can Jiang, Junlong Zou, Jie Yang, Kuiwen Xu, Chaoyuan Jin, Gaofeng Wang, Gian Piero Puccioni, Gian Luca Lippi   +8 more
doaj   +1 more source

Speckle noise and dynamic range in coronagraphic images [PDF]

, 2007
This paper is concerned with the theoretical properties of high contrast coronagraphic images in the context of exoplanet searches. We derive and analyze the statistical properties of the residual starlight in coronagraphic images, and describe the ...
Andre Ferrari, Cagigal M. P., Canales V. F., Claude Aime, Codona J. L., Gladysz S., Laurent Jolissaint, Lyot B., Macintosh B. A., Marois C., Moffat A. F. J., Remi Soummer, Roddier F., Serabyn E., Shaklan S. B., Wallace J. K.   +15 more
core   +1 more source

Laser Speckle Reduction Using a Liquid Crystal Diffuser Enhanced with Redox Dopants

Advanced Photonics Research, 2021
Herein, a large reduction in the speckle noise is observed using a thin electroresponsive film consisting of a chiral nematic liquid crystal (LC) that has been enhanced with the addition of a redox dopant.
Yihan Jin, David J. Hansford, Steve J. Elston, Stephen M. Morris   +3 more
doaj   +1 more source

SAR Image Despeckling by Deep Neural Networks: from a Pre-Trained Model to an End-to-End Training Strategy

Remote Sensing, 2020
Speckle reduction is a longstanding topic in synthetic aperture radar (SAR) images. Many different schemes have been proposed for the restoration of intensity SAR images.
Emanuele Dalsasso, Xiangli Yang, Loïc Denis, Florence Tupin, Wen Yang   +4 more
doaj   +1 more source

Speckle noise reduction techniques for high-dynamic range imaging [PDF]

, 2007
High-dynamic range imaging from space in the visible, aiming in particular at the detection of terrestrial exoplanets, necessitates not only the use of a coronagraph, but also of adaptive optics to correct optical defects in real time.
Belikov, Belikov, Bordé, Bordé, Bordé, Codona, Dohlen, Give'on, Guyon, Guyon, Guyon, Kasdin, Kuchner, Lyot, Malbet, Pascal Bordé, Putnam, Roddier, Rouan, Shaklan, Traub, Trauger, Trauger, Wesley Traub   +23 more
core   +3 more sources

Implementation of a Current Drive Modulator for Effective Speckle Suppression in a Laser Projection System

IEEE Photonics Journal, 2015
We report on the implementation of a current drive modulation circuitry that is effective in suppressing speckle noise for laser diodes. The drive circuit allows for operating the laser diode current at constant dc or modulating the current with square ...
I. Yilmazlar, M. Sabuncu
doaj   +1 more source

Wavelet-based denoising for 3D OCT images [PDF]

, 2007
Optical coherence tomography produces high resolution medical images based on spatial and temporal coherence of the optical waves backscattered from the scanned tissue.
De Keyser, Paul, Dhaenens, Frans, Jovanov, Ljubomir, Philips, Wilfried, Pizurica, Aleksandra, Zlokolica, Vladimir   +5 more
core   +1 more source

SAR Image Change Detection Based on Nonlocal Low-Rank Model and Two-Level Clustering

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2020
Change detection (CD) has found a wide range of applications in many fields. In this article, we propose a novel nonlocal low-rank (NLR) based method for multitemporal synthetic aperture radar image CD. This method jointly exploits the powerful NLR-based
Yuli Sun, Lin Lei, Dongdong Guan, Xiao Li, Gangyao Kuang   +4 more
doaj   +1 more source