Results 51 to 60 of about 3,110,122 (363)
Multimodal real-time imaging with laser speckle contrast and fluorescent contrast
Photodiagnosis and Photodynamic Therapy, 2023 Laser speckle contrast imaging (LSCI) can achieve real-time 2D perfusion maps non-invasively. However, LSCI is still difficult to use in general clinical applications because of movement sensitivity and limitations in blood flow analysis. To overcome this, fluorescence imaging (FI) is combined with LSCI using a light source with a wavelength of 785 nm ...
Hyun-Seo Park +5 more
openaire +3 more sources
The coherent differential imaging on speckle area nulling (CDI-SAN) method for high-contrast imaging under speckle variation [PDF]
, 2022 Differential imaging is a postprocessing method to obtain high contrast, often used for exoplanet searches. The coherent differential imaging on speckle area nulling (CDI-SAN) method was developed to detect a faint exoplanet lying beneath residual speckles of a host star.
arxiv +1 more source
Coronagraph Experiment on Dark-hole Control by Speckle Area Nulling Method [PDF]
Optical Review 22 (2015) 736-740, 2022 In high-contrast imaging optical systems for direct observation of planets outside our solar system, adaptive optics with an accuracy of lambda/10,000 root mean square is required to reduce the speckle noise down to 1e-10 level in addition to the nulling coronagraph which eliminate the diffracted light.
arxiv +1 more source
Synthetic exposure with a CMOS camera for multiple exposure speckle imaging of blood flow
Scientific Reports, 2022 Speckle contrast imaging is an established technique to obtain relative blood flow maps over wide fields of view. A major improvement of the method relies on the acquisition of raw speckle images at different exposure times but requires simultaneous ...
M. Chammas, F. Pain
doaj +1 more source
Applied Sciences, 2022 Coherent plane-wave compounding (CPWC) enables high-frame-rate ultrasound imaging, but the imaging quality is mainly determined by the beamforming method.
Yuanguo Wang +3 more
doaj +1 more source
The Mysterious Lives Of Speckles. I. Residual atmospheric speckle lifetimes in ground-based coronagraphs [PDF]
, 2021 High-contrast imaging observations are fundamentally limited by the spatially and temporally correlated noise source called speckles. Suppression of speckle noise is the key goal of wavefront control and adaptive optics (AO), coronagraphy, and a host of post-processing techniques.
arxiv +1 more source
Journal of Biomedical Optics, 2010 Laser speckle contrast imaging is a technique used for imaging blood flow without scanning. Though several studies have attempted to combine spatial and temporal statistics of laser speckle images for reducing image noise as well as preserving acceptable spatiotemporal resolution, the statistical accuracy of these spatiotemporal methods has not been ...
Jia Wang +5 more
openaire +3 more sources
Vector speckle grid: instantaneous incoherent speckle grid for high-precision astrometry and photometry in high-contrast imaging [PDF]
A&A 638, A118 (2020), 2020 Photometric and astrometric monitoring of directly imaged exoplanets will deliver unique insights into their rotational periods, the distribution of cloud structures, weather, and orbital parameters. As the host star is occulted by the coronagraph, a speckle grid (SG) is introduced to serve as astrometric and photometric reference.
arxiv +1 more source
Optics Express, 2013 In laser speckle contrast imaging, it was usually suggested that speckle size should exceed two camera pixels to eliminate the spatial averaging effect. In this work, we show the benefit of enhancing signal to noise ratio by correcting the speckle contrast at small speckle size.
Jianjun Qiu +4 more
openaire +3 more sources
Scientific Reports, 2020 Speckle reduction is an important topic in holographic displays as speckles not only reduce signal-to-noise ratio but also possess an eye-safety issue. Despite thorough exploration of speckle reduction methods using partially coherent light sources, the ...
Seungjae Lee +5 more
semanticscholar +1 more source