Improving signal-to-noise ratio of computationalghost imaging of the reflective object with roughsurface by Hadamard modulated light field

2021 ◽  
Author(s):  
Mingshu Lu ◽  
Xuanpengfan Zou ◽  
liyu zhou ◽  
Suqin Nan ◽  
Teng Jiang ◽  
...  
Keyword(s):  
Light Field ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Modulated Light

scholarly journals Lens-free Multi-Laser Spectral Light-Field Fusion Microscopy

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Farnoud Kazemzadeh ◽  
Alexander Wong
Keyword(s):  
Light Field ◽  
Signal To Noise Ratio ◽  
Field Of View ◽  
Large Field ◽  
Light Fields ◽  
Signal To Noise ◽  
Pulsed Mode ◽  
Noise Ratio ◽  
Spectral Complex

<p>We present a device and method for performing lens-free spectral<br />light-field fusion microscopy at sub-pixel resolutions while taking<br />advantage of the large field-of-view capability. A collection of<br />lasers at different wavelengths is used in pulsed mode and enables<br />the capture of interferometric light-field encodings of a specimen<br />placed near the detector. Numerically fusing the spectral complex<br />light-fields obtained from the encodings produces an image of the<br />specimen at higher resolution and signal-to-noise-ratio while suppressing<br />various aberrations and artifacts.</p>

scholarly journals Protocol for the Design and Assembly of a Light Sheet Light Field Microscope

2019 ◽  
Vol 2 (3) ◽  
pp. 56 ◽  
Author(s):  
Jorge Madrid-Wolff ◽  
Manu Forero-Shelton
Keyword(s):  
Neural Activity ◽  
Light Field ◽  
Signal To Noise Ratio ◽  
Light Sheet ◽  
High Temporal Resolution ◽  
Single Camera ◽  
Signal To Noise ◽  
Light Sheet Microscopy ◽  
Recent Method ◽  
Noise Ratio

Light field microscopy is a recent development that makes it possible to obtain images of volumes with a single camera exposure, enabling studies of fast processes such as neural activity in zebrafish brains at high temporal resolution, at the expense of spatial resolution. Light sheet microscopy is also a recent method that reduces illumination intensity while increasing the signal-to-noise ratio with respect to confocal microscopes. While faster and gentler to samples than confocals for a similar resolution, light sheet microscopy is still slower than light field microscopy since it must collect volume slices sequentially. Nonetheless, the combination of the two methods, i.e., light field microscopes that have light sheet illumination, can help to improve the signal-to-noise ratio of light field microscopes and potentially improve their resolution. Building these microscopes requires much expertise, and the resources for doing so are limited. Here, we present a protocol to build a light field microscope with light sheet illumination. This protocol is also useful to build a light sheet microscope.

scholarly journals Comparing volumetric reconstruction algorithms for light field imaging of high signal-to-noise ratio neuronal calcium transients

2020 ◽  
Author(s):  
Carmel L. Howe ◽  
Peter Quicke ◽  
Pingfan Song ◽  
Herman Verinaz Jadan ◽  
Pier Luigi Dragotti ◽  
...  
Keyword(s):  
Light Field ◽  
Signal To Noise Ratio ◽  
Brain Slices ◽  
Three Dimensions ◽  
High Signal ◽  
Reconstruction Algorithms ◽  
Signal To Noise ◽  
Neuronal Processes ◽  
Noise Ratio ◽  
Fast Light

AbstractLight field microscopy (LFM) enables fast, light efficient, volumetric imaging of neuronal activity with functional fluorescence indicators. Here we apply LFM to single-cell and bulk-labeled imaging of the red calcium dye, CaSiR-1 in acute mouse brain slices. We compare two common light field volume reconstruction algorithms: synthetic refocusing and Richardson-Lucy 3D deconvolution. We compare temporal signal-to-noise ratio (SNR) and spatial signal confinement between the two LFM algorithms and conventional widefield image series. Both algorithms can resolve calcium signals from neuronal processes in three dimensions. Increasing deconvolution iteration number improves spatial signal confinement but reduces SNR compared to synthetic refocusing.

Determination of the Best Emulsion for the Microscopy of Crystals

1981 ◽  
Vol 39 ◽  
pp. 32-33
Author(s):  
David A. Grano ◽  
Kenneth H. Downing
Keyword(s):  
Spatial Frequency ◽  
Information Transfer ◽  
Signal To Noise Ratio ◽  
Experimental Situation ◽  
Photographic Emulsion ◽  
Modulation Transfer ◽  
Signal To Noise ◽  
Frequency Space ◽  
Noise Ratio

The retrieval of high-resolution information from images of biological crystals depends, in part, on the use of the correct photographic emulsion. We have been investigating the information transfer properties of twelve emulsions with a view toward 1) characterizing the emulsions by a few, measurable quantities, and 2) identifying the “best” emulsion of those we have studied for use in any given experimental situation. Because our interests lie in the examination of crystalline specimens, we've chosen to evaluate an emulsion's signal-to-noise ratio (SNR) as a function of spatial frequency and use this as our critereon for determining the best emulsion.The signal-to-noise ratio in frequency space depends on several factors. First, the signal depends on the speed of the emulsion and its modulation transfer function (MTF). By procedures outlined in, MTF's have been found for all the emulsions tested and can be fit by an analytic expression 1/(1+(S/S0)2). Figure 1 shows the experimental data and fitted curve for an emulsion with a better than average MTF. A single parameter, the spatial frequency at which the transfer falls to 50% (S0), characterizes this curve.

Experiments in Bright-Field Imaging with Hollow-Cone Illumination

1981 ◽  
Vol 39 ◽  
pp. 226-227
Author(s):  
W. Kunath ◽  
K. Weiss ◽  
E. Zeitler
Keyword(s):  
Signal To Noise Ratio ◽  
Carbon Support ◽  
Electronic System ◽  
Optic Axis ◽  
Hollow Cone ◽  
Signal To Noise ◽  
Bright Field ◽  
Noise Ratio ◽  
Single Field ◽  
Field Imaging

Bright-field images taken with axial illumination show spurious high contrast patterns which obscure details smaller than 15 ° Hollow-cone illumination (HCI), however, reduces this disturbing granulation by statistical superposition and thus improves the signal-to-noise ratio. In this presentation we report on experiments aimed at selecting the proper amount of tilt and defocus for improvement of the signal-to-noise ratio by means of direct observation of the electron images on a TV monitor.Hollow-cone illumination is implemented in our microscope (single field condenser objective, Cs = .5 mm) by an electronic system which rotates the tilted beam about the optic axis. At low rates of revolution (one turn per second or so) a circular motion of the usual granulation in the image of a carbon support film can be observed on the TV monitor. The size of the granular structures and the radius of their orbits depend on both the conical tilt and defocus.

Information capacity and bandwidth limitations in the SEM

1989 ◽  
Vol 47 ◽  
pp. 84-85
Author(s):  
D. C. Joy ◽  
R. D. Bunn
Keyword(s):  
Signal To Noise Ratio ◽  
Critical Dimension ◽  
Information Capacity ◽  
Acquisition Time ◽  
Signal To Noise ◽  
Sem Image ◽  
Probe Size ◽  
Minimum Number ◽  
Noise Ratio ◽  
Signal Channel

The information available from an SEM image is limited both by the inherent signal to noise ratio that characterizes the image and as a result of the transformations that it may undergo as it is passed through the amplifying circuits of the instrument. In applications such as Critical Dimension Metrology it is necessary to be able to quantify these limitations in order to be able to assess the likely precision of any measurement made with the microscope.The information capacity of an SEM signal, defined as the minimum number of bits needed to encode the output signal, depends on the signal to noise ratio of the image - which in turn depends on the probe size and source brightness and acquisition time per pixel - and on the efficiency of the specimen in producing the signal that is being observed. A detailed analysis of the secondary electron case shows that the information capacity C (bits/pixel) of the SEM signal channel could be written as :

Speech Reception in the Presence of Classroom Noise

1979 ◽  
Vol 10 (4) ◽  
pp. 221-230 ◽  
Author(s):  
Veronica Smyth
Keyword(s):  
Signal To Noise Ratio ◽  
Learning Processes ◽  
Speech Discrimination ◽  
Signal To Noise ◽  
Speech Reception ◽  
Monosyllabic Words ◽  
Noise Ratio

Three hundred children from five to 12 years of age were required to discriminate simple, familiar, monosyllabic words under two conditions: 1) quiet, and 2) in the presence of background classroom noise. Of the sample, 45.3% made errors in speech discrimination in the presence of background classroom noise. The effect was most marked in children younger than seven years six months. The results are discussed considering the signal-to-noise ratio and the possible effects of unwanted classroom noise on learning processes.

Quantifying the Effects of Background Speech Babble on Preschool Children's Novel Word Learning in a Multisession Paradigm: A Preliminary Study

2020 ◽  
Vol 63 (1) ◽  
pp. 345-356
Author(s):  
Meital Avivi-Reich ◽  
Megan Y. Roberts ◽  
Tina M. Grieco-Calub
Keyword(s):  
Word Learning ◽  
Signal To Noise Ratio ◽  
Preschool Age ◽  
Exposure Condition ◽  
Signal To Noise ◽  
Verbal Recall ◽  
Referent Selection ◽  
Main Effect ◽  
Noise Ratio ◽  
Novel Word Learning

Purpose This study tested the effects of background speech babble on novel word learning in preschool children with a multisession paradigm. Method Eight 3-year-old children were exposed to a total of 8 novel word–object pairs across 2 story books presented digitally. Each story contained 4 novel consonant–vowel–consonant nonwords. Children were exposed to both stories, one in quiet and one in the presence of 4-talker babble presented at 0-dB signal-to-noise ratio. After each story, children's learning was tested with a referent selection task and a verbal recall (naming) task. Children were exposed to and tested on the novel word–object pairs on 5 separate days within a 2-week span. Results A significant main effect of session was found for both referent selection and verbal recall. There was also a significant main effect of exposure condition on referent selection performance, with more referents correctly selected for word–object pairs that were presented in quiet compared to pairs presented in speech babble. Finally, children's verbal recall of novel words was statistically better than baseline performance (i.e., 0%) on Sessions 3–5 for words exposed in quiet, but only on Session 5 for words exposed in speech babble. Conclusions These findings suggest that background speech babble at 0-dB signal-to-noise ratio disrupts novel word learning in preschool-age children. As a result, children may need more time and more exposures of a novel word before they can recognize or verbally recall it.

On the Signal-to-Noise Ratio for Boolean Functions

2020 ◽  
Vol E103.A (12) ◽  
pp. 1659-1665
Author(s):  
Yu ZHOU ◽  
Wei ZHAO ◽  
Zhixiong CHEN ◽  
Weiqiong WANG ◽  
Xiaoni DU
Keyword(s):  
Boolean Functions ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Noise Ratio
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