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Efficient Deformable Shape Correspondence via Kernel Matching [article]

Zorah Lähner, Matthias Vestner, Amit Boyarski, Or Litany, Ron Slossberg, Tal Remez, Emanuele Rodolà, Alex Bronstein, Michael Bronstein, Ron Kimmel, Daniel Cremers
2017 arXiv   pre-print
difference of convex functions (DC) programming.  ...  Surprisingly, in spite of the highly non-convex nature of the resulting quadratic assignment problem, our method converges to a semantically meaningful and continuous mapping in most of our experiments  ...  matrices B n and E is strictly convex and differentiable.  ... 
arXiv:1707.08991v3 fatcat:rosyjwcobrgupio4xamppthws4

Recovering Transparent Shape from Time-of-Flight Distortion

Kenichiro Tanaka, Yasuhiro Mukaigawa, Hiroyuki Kubo, Yasuyuki Matsushita, Yasushi Yagi
2016 2016 IEEE Conference on Computer Vision and Pattern Recognition (CVPR)  
Although this problem is not strictly convex, we observed that this problem is approximately convex 5 ; hence the optimal solution can be obtained.  ...  Discussions We developed a method for transparent shape recovery using the time-of-flight distortion.  ... 
doi:10.1109/cvpr.2016.475 dblp:conf/cvpr/TanakaMKMY16 fatcat:omk3a6u2kjdxji57zzh5d7yztu

Efficient determination of shape from multiple images containing partial information

R. Basri, A. Grove, D. Jacobs
1996 Proceedings of 13th International Conference on Pattern Recognition  
We consider the problem of reconstructing the shape of a 2-D object from multiple partial images related by scaled translations, in the presence of occlusion.  ...  Finally, we consider the case where the object is known to be convex.  ...  We view this situation as a special case of the problem of shape recovery in the presence of occlusion.  ... 
doi:10.1109/icpr.1996.546032 dblp:conf/icpr/BasriGJ96 fatcat:fr6xx37ywjaidiookzbgfm7nue

Functional Convex Averaging and Synchronization for Time-Warped Random Curves

Xueli Liu, Hans-Georg Müller
2004 Journal of the American Statistical Association  
Previous analyses of warping typically have not been based on a model in which individual observed curves are viewed as realizations of a stochastic process.  ...  We propose a functional convex synchronization model, under the premise that each observed curve is the realization of a stochastic process.  ...  The functional convex average clearly leads to improved recovery of the target function τ (·) in these simulation examples, and the functional convex mean provides a reasonable representation of shapes  ... 
doi:10.1198/016214504000000999 fatcat:ajwxk2fl45hqji4ybbxmv7wz6u

Exploiting Residue Curve Maps to Assess Thermodynamic Feasibility Boundaries under Uncertain Operating Conditions

Alessandro Di Pretoro, Ludovic Montastruc, Flavio Manenti, Xavier Joulia
2020 Industrial & Engineering Chemistry Research  
The final product of this study is a thorough procedure to determine the flexibility boundaries of feed and product compositions as well as an immediate and intuitive graphical representation from a binary  ...  An ABE/W (acetone−butanol−ethanol/water) mixture was then selected as a case study since it allows us to discuss several non-ideal thermodynamic behaviors and because of the renewed interest in biorefinery  ...  Finally, according to the shape of the N-dimensional separatrix boundary, RCM graphical representations allow us to predict the effect of the presence of a further component in the feed stream from a flexibility  ... 
doi:10.1021/acs.iecr.0c02383 fatcat:kza2v52canh4npubjx3ebmo6fa

Uncalibrated Photometric Stereo for Unknown Isotropic Reflectances

Feng Lu, Yasuyuki Matsushita, Imari Sato, Takahiro Okabe, Yoichi Sato
2013 2013 IEEE Conference on Computer Vision and Pattern Recognition  
Based on these observations, we show that surface normals can be estimated up to a convex/concave ambiguity.  ...  Our method uses a pixel intensity profile, which is a sequence of radiance intensities recorded at a pixel across multi-illuminance images.  ...  ., a hemisphere, a spherical cap whose surface normals deviate from the viewing direction by 0 • ∼ 75 • , and another spherical cap with the smaller range of 0 • ∼ 60 • , as shown in Fig. 6 .  ... 
doi:10.1109/cvpr.2013.196 dblp:conf/cvpr/LuMSOS13 fatcat:dqnp7ryxubcdvps4blxkaqorpe

A theory of shape by space carving

K.N. Kutulakos, S.M. Seitz
1999 Proceedings of the Seventh IEEE International Conference on Computer Vision  
By studying the equivalence class of all 3D shapes that reproduce the input photographs, we prove the existence of a special member of this class, the photo hull, that 1 can be computed directly from photographs  ...  In this paper we consider the problem of computing the 3D shape of an unknown, arbitrarily-shaped scene from multiple photographs taken at known but arbitrarily-distributed viewpoints.  ...  The closed photo hull therefore satis es our de nition of a shape. 16 Note that such a point does exist since P N is a closed and bounded subset of IR 3 and hence it is compact Armstrong, 1983.  ... 
doi:10.1109/iccv.1999.791235 dblp:conf/iccv/KutulakosS99 fatcat:e663bpprprcrtmlbus2ex4nxzm

Gradient-based surface reconstruction using compressed sensing

Mohammad Rostami, Oleg Michailovich, Zhou Wang
2012 2012 19th IEEE International Conference on Image Processing  
Surface reconstruction from measurements of spatial gradient is an important computer vision problem with applications in photometric stereo and shape-from-shading.  ...  DCS can be viewed as a modification of the classical compressed sensing (CS), which is particularly suited for reconstructions involving image/surface gradients.  ...  Note that the problem (2) is strictly convex, and hence admits a unique minimizer.  ... 
doi:10.1109/icip.2012.6467009 dblp:conf/icip/RostamiMW12 fatcat:ijdavrv22feoxj3rvmz2xftqvy

Robust surface normal estimation via greedy sparse regression

Mingjing Zhang, Mark S. Drew
2015 EURASIP Journal on Image and Video Processing  
Photometric stereo (PST) is a widely used technique of estimating surface normals from an image set. However, it often produces inaccurate results for non-Lambertian surface reflectance.  ...  This allows for a large repertoire of existing sparse recovery algorithms to be more straightforwardly applied to the PST problem.  ...  Acknowledgements The authors would like to thank the anonymous referees for their insightful comments and suggestions, which help improve the quality of the current study substantially.  ... 
doi:10.1186/s13640-015-0098-x fatcat:z3dap3sdyzadxbznkbl7yd4ckq

Convex Cardinal Shape Composition [article]

Alireza Aghasi, Justin Romberg
2015 arXiv   pre-print
Applications vary from shape-based characterization, object tracking, optical character recognition, and shape recovery in occlusion, to other disciplines such as the geometric packing problem.  ...  This is a combinatorial problem solving which requires an exhaustive search among a large number of possibilities. We propose a convex relaxation to the problem to make it computationally tractable.  ...  Inspired by ideas from sparse recovery, the 1 constraint is used to control the number of active shapes in the final representation.  ... 
arXiv:1501.01347v2 fatcat:2wsty455o5a4blmplu4pph2jcu

LASSO ISOtone for High Dimensional Additive Isotonic Regression [article]

Zhou Fang, Nicolai Meinshausen
2010 arXiv   pre-print
In this article, we present a new method for such regression called LASSO Isotone (LISO). LISO adapts ideas from sparse linear modelling to additive isotonic regression.  ...  We suggest an algorithm involving a modification of the backfitting algorithm CPAV. We give a numerical convergence result, and finally examine some of its properties through simulations.  ...  In this case, the loglikelihood residual sum of squares term is strictly convex, and so, as a strictly convex optimisation on a convex set, an unique solution exists.  ... 
arXiv:1006.2940v1 fatcat:slrhm5uherezpjk5a7irp42nse

Convex Cardinal Shape Composition

Alireza Aghasi, Justin Romberg
2015 SIAM Journal of Imaging Sciences  
Applications vary from shape-based characterization, object tracking, optical character recognition, and shape recovery in occlusion to other disciplines such as the geometric packing problem.  ...  This is a combinatorial problem solving which requires an exhaustive search among a large number of possibilities. We propose a convex relaxation to the problem to make it computationally tractable.  ...  Accurate recovery of the shape elements.  ... 
doi:10.1137/151003088 fatcat:ds3ulnaklvghlkmjlg632qxqy4

Recovering Facial Shape Using a Statistical Model of Surface Normal Direction

W.A.P. Smith, E.R. Hancock
2006 IEEE Transactions on Pattern Analysis and Machine Intelligence  
In this paper, we show how a statistical model of facial shape can be embedded within a shape-from-shading algorithm.  ...  We demonstrate that the combination of a global statistical constraint and local irradiance constraint yields an efficient and accurate approach to facial shape recovery and is capable of recovering fine  ...  This suggests that, in some cases, human shape-from-shading makes use of prior class knowledge to constrain the shape recovery process.  ... 
doi:10.1109/tpami.2006.251 pmid:17108367 fatcat:7y6jqn2qofhm3ahwxla5x2axcm

Computing with Connections In Visual Recognition of Origami Objects*

Daniel Sabbah
1985 Cognitive Science  
The idea is that object shape can be described in terms of geometric parameters, hence an object in an image can be represented as a point in the n-dimensional space defined by the n describing parameters  ...  Finally, because it allows for quantitative shape recovery necessary to construct and match rotationally invariant representations of Origami objects.  ... 
doi:10.1207/s15516709cog0901_3 fatcat:dutdwv4mbbc6lbaoelxlrspg3y

Computing with connections in visual recognition of origami objects

D SABBAH
1985 Cognitive Science  
The idea is that object shape can be described in terms of geometric parameters, hence an object in an image can be represented as a point in the n-dimensional space defined by the n describing parameters  ...  Finally, because it allows for quantitative shape recovery necessary to construct and match rotationally invariant representations of Origami objects.  ... 
doi:10.1016/s0364-0213(85)80008-2 fatcat:i5x35a4w4fe6fm7qjwq6l65wla
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