Filters








6,646 Hits in 3.9 sec

Optimising Aperture Shapes for Depth Estimation [article]

Anita Sellent, Paolo Favaro
2013 International Symposium on Vision, Modeling, and Visualization  
The proposed mask optimisation procedure is applicable for different depth estimation scenarios.  ...  This blur shape can be manipulated by introducing masks into the main lens aperture. We propose an intuitive criterion to design aperture patterns for depth estimation.  ...  Depth estimation with optimised apertures on clean images is more accurate than with the reference masks in all cases.  ... 
doi:10.2312/pe.vmv.vmv13.219-220 dblp:conf/vmv/SellentF13 fatcat:oc62o3w3sfa7domttbo6jqsx7m

Optimized aperture shapes for depth estimation

Anita Sellent, Paolo Favaro
2014 Pattern Recognition Letters  
The proposed mask optimisation procedure is applicable for different depth estimation scenarios.  ...  This blur shape can be manipulated by introducing masks into the main lens aperture. We propose an intuitive criterion to design aperture patterns for depth estimation.  ...  Depth estimation with optimised apertures on clean images is more accurate than with the reference masks in all cases.  ... 
doi:10.1016/j.patrec.2013.12.019 fatcat:nss66z365rg57mvj7smtjgltzy

Geometrical Shape Optimization of a Cavity Receiver Using Coupled Radiative and Hydrodynamic Modeling

C.-A. Asselineau, J. Zapata, J. Pye
2015 Energy Procedia  
By using a two-stage optimisation process we maximise the heat rate output of a four-parameter axisymmetric direct steam generation cavity receiver.  ...  We show that a significant range of geometrical shapes show similar efficiencies while having different wall flux and temperature profiles.  ...  Thermal emissions are here estimated using only two elements per cavity shape and constant temperature estimation for each of these.  ... 
doi:10.1016/j.egypro.2015.03.032 fatcat:o4jgtvmz5bbzzdmehyhf3caguy

Comparison of closed loop and sensorless adaptive optics in widefield optical microscopy

C. Bourgenot, C. D. Saunter, G. D. Love, J. M. Girkin
2013 Journal of the European Optical Society-Rapid Publications  
shapes.  ...  The accuracy of the loop is limited by the contribution of the spot shape to the centre of mass measurement and also by the partial covering of the pupil by the sub-apertures leaving the very edge of the  ... 
doi:10.2971/jeos.2013.13027 fatcat:2byfycovjvgrvnowdcnmv74uye

Phase estimation for global defocus correction in optical coherence tomography

Mikkel Jensen, Niels M. Israelsen, Ole Bang, Adrian Podoleanu, Ole Bang, Adrian Podoleanu
2018 2nd Canterbury Conference on OCT with Emphasis on Broadband Optical Sources  
In this work we investigate three techniques for estimation of the non-linear phase present due to defocus in optical coherence tomography, and apply them with the angular spectrum method.  ...  The estimated phase of a single en-face image is used to extrapolate the non-linear phase at all depths, which in the end can be used to correct the entire 3-D tomogram, and any other tomogram from the  ...  ACKNOWLEDGMENTS All authors acknowledge support from Innovation Fund Denmark through the Shape OCT grant No. 4107-00011A.  ... 
doi:10.1117/12.2292547 fatcat:hst2r63aebcfxi5iokhxqvru2m

New planetary and eclipsing binary candidates from campaigns 1−6 of the K2 mission

S. C. C. Barros, O. Demangeon, M. Deleuil
2016 Astronomy and Astrophysics  
Our pipeline is optimised for bright stars for which spectroscopic follow-up is possible. We achieve a maximum precision on 6 hours of 6 ppm.  ...  Our method is based on many years of experience in planet hunting for the CoRoT mission.  ...  The optimised aperture is calculated with a data clustering algorithm called densitybased spatial clustering of applications with noise (dbscan) and their reduction is optimised for asteroseismology studies  ... 
doi:10.1051/0004-6361/201628902 fatcat:352f32nqr5g67d7smdvquzcwey

Light sheet adaptive optics microscope for 3D live imaging

C. Bourgenot, J. M. Taylor, C. D. Saunter, J. M. Girkin, G. D. Love, Carol J. Cogswell, Thomas G. Brown, Jose-Angel Conchello, Tony Wilson
2013 Three-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing XX  
Please consult the full Durham E-Theses policy for further details. Abstract Optical microscopy is still the main research tool for many biological studies.  ...  The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes  ...  (a,b,c) are images taken for a flat mirror shape, a mirror shape optimised for the system aberrations, and for a mirror shape optimised directly on the fish.  ... 
doi:10.1117/12.2002057 fatcat:zao646tyczf4tp4f4pwnvs6s6i

The 3-D Positioning of Wireless Sensors in Dispersive Propagation Media

John G. Davis, Robin Sloan, Anthony J. Peyton
2013 IEEE Transactions on Instrumentation and Measurement  
Consequently, although wide bandwidth electromagnetic pulses exhibit greater resolution in free space, this parameter along with the pulse penetration depth, may be reduced considerably due to differential  ...  formulated as a nonlinear least squares problem in which the misfit between time domain positioning measurements and modelled data is minimized via application of a novel minimum single level linkage optimisation  ...  Acknowledgements The authors would like to acknowledge the support of the EPSRC for funding the above  ... 
doi:10.1109/tim.2013.2255980 fatcat:z2prz7odwrbgxfyvmnxrplpd3q

Exploring high-frequency eddy-current testing for sub-aperture defect characterisation using parametric-manifold mapping [article]

Robert R. Hughes, Bruce W. Drinkwater
2021 arXiv   pre-print
Finally the technique is applied to finite rectangular notch defects of surface extents smaller than the diameter of the inspection coil (sub-aperture) over a range of frequencies.  ...  The approach is used to characterise the depth of a sloped slot demonstrating good accuracy up to ~2.0 mm in depth over a broad range of sub-resonance frequencies, indicating applications in geometric  ...  John Bowler & Dr Alexander Velichko for their advise and insight, as well as James Wilcox from Rolls-Royce plc (NDT lab) for sizing and providing X-ray CT images of test specimen defects.  ... 
arXiv:2102.04778v1 fatcat:s4q56zwz6zegphrxsad2n3mhwy

A novel, high-welfare methodology for evaluating poultry red mite interventions in vivo

Francesca Nunn, Kathryn Bartley, Javier Palarea-Albaladejo, Giles T. Innocent, Frank Turnbull, Harry W. Wright, Alasdair J. Nisbet
2019 Veterinary parasitology  
By optimising the depth and width of the mesh aperture size we have produced a device which will lead to both reduction and refinement in the use of animals in research, allowing the pre-screening of new  ...  For optimal use, the device should be constructed from 105 μm aperture width, 63 μm depth, polyester mesh and the mites (irrespective of life stage) should be conditioned with no access to food for 3 weeks  ...  Lise Roy (Montpellier University) for her helpful advice on D. gallinae morphology.  ... 
doi:10.1016/j.vetpar.2019.01.011 pmid:30878084 fatcat:gr6difvoyvchtfad7empplsq7a

An innovative, highly sensitive receiver system for the Square Kilometre Array Mid Radio Telescope

Gie Han Tan, Robert Lehmensiek, Bhushan Billade, Krzysztof Caputa, Stéphane Gauffre, Isak P. Theron, Miroslav Pantaleev, Zoran Ljusic, Benjamin Quertier, Adriaan Peens-Hough, Helen J. Hall, Roberto Gilmozzi (+1 others)
2016 Ground-based and Airborne Telescopes VI  
SKA1-Mid (350 MHz -13.8 GHz with an option for an upper limit of ~24 GHz) will consist of 133 reflector antennas using an unblocked aperture, offset Gregorian configuration with an effective diameter of  ...  The unblocked aperture results in increased aperture efficiency and lower side-lobe levels compared to a traditional on-axis configuration.  ...  The sensitivity can be optimised for a given SLL by shaping the reflector system. Maximising the aperture efficiency does not, in general, correspond to maximising the receiving sensitivity.  ... 
doi:10.1117/12.2230897 fatcat:xthqy3rww5agvbsij5ildtp7ny

Reducing and constraining the intrinsic galaxy alignment contamination to weak lensing measurements [article]

Catherine Heymans & Alan Heavens
2003 arXiv   pre-print
the aperture mass B-mode in the Red-Sequence Cluster Survey.  ...  Intrinsic galaxy alignments, although an annoying contaminant for cosmic shear studies, are interesting in their own right, and we therefore present a new observational constraint for their amplitude from  ...  We propose a simple optimised scheme for multi-colour surveys and show its effect for the Sloan photometric survey design and the RCS survey design.  ... 
arXiv:astro-ph/0310495v1 fatcat:kbcr63p7ubeufip6amdz3hh2u4

QUANTIFYING DEPTH OF FIELD AND SHARPNESS FOR IMAGE-BASED 3D RECONSTRUCTION OF HERITAGE OBJECTS

E. K. Webb, S. Robson, R. Evans
2020 The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences  
and optimise structure from motion (SfM) and multiview stereo (MVS) workflows.  ...  of confusion" has not yet been quantified for the 3D case.  ...  ACKNOWLEDGEMENTS This work is part of a PhD at the University of Brighton and University College London through the EPSRC funded Science and Engineering Arts Heritage and Archaeology (SEAHA) Centre for  ... 
doi:10.5194/isprs-archives-xliii-b2-2020-911-2020 fatcat:rltdzzildjeuzbve3jjtvtt7kq

Rational-operator-based depth-from-defocus approach to scene reconstruction

Ang Li, Richard Staunton, Tardi Tjahjadi
2013 Optical Society of America. Journal A: Optics, Image Science, and Vision  
The corrected depth is thus estimated by An example of the corrected depth map is shown in Fig. 3(b) and (e), where the working range is within [886.8 933] mm away from the lens.  ...  A typical correction of a depth map only accounts for 4-8% of the total RO-DfD computational time, hence it is suitable for real-time applications.  ...  Introduction Depth from Defocus (DfD) and Depth from Focus (DfF) are methods for recovering 3dimensional (3D) shape of a scene.  ... 
doi:10.1364/josaa.30.001787 pmid:24323260 fatcat:qtf3ustyqrf5tlzkcwo76slvfu

Depth extraction by focal/aperture variation

S. R. Daniel
1990 Procedings of the British Machine Vision Conference 1990  
We then outline various methods that are available for solving these systems. We will consider methods which give an estimate of the solution and those which give a statistically optimal' solution.  ...  These images contain the necessary coded depth information. By using one image (that with the smallest aperture) as a reference and using knowledge of the.  ...  We will only be able to obtain reliable depth estimates for those points in I(x,y) which have sufficient grey-level gradient. 3D/D = ( D/u -1 ) da/a (4.1) which gives the following graph for a 2 % error  ... 
doi:10.5244/c.4.50 dblp:conf/bmvc/Daniel90 fatcat:fpmkplqt2nfefj7kjllv3jnm64
« Previous Showing results 1 — 15 out of 6,646 results