bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compressive Image Reconstruction in Reduced Union of Subspaces
Authors: Miandji Ehsan , Kronander Joel , Unger Jonas 
Published: June 2015

AbstractWe present a new compressed sensing framework for reconstruction of incomplete and possibly noisy images and their higher dimensional variants, e.g. animations and light‐fields. The algorithm relies on a learning‐based basis representation. We train an ensemble of intrinsically two‐dimensional (2D) dictionaries that operate locally on a set of 2D patches extracted from the input data. We show that one can convert the problem of 2D sparse signal recovery to an equivalent 1D form, enabling us to utilize a large family of sparse solvers. The proposed framework represents the input signals in a reduced union of subspaces model, while allowing sparsity in each subspace. Such a model leads to a much more sparse representation than widely used methods such as K‐SVD. To evaluate our method, we apply it to three different scenarios where the signal dimensionality varies from 2D (images) to 3D (animations) and 4D (light‐fields). We show that our method outperforms state‐of‐the‐art algorithms in computer graphics and image processing literature.
IsoMatch: Creating Informative Grid Layouts
Authors: Fried O. , DiVerdi S. , Halber M. , Sizikova E. , Finkelstein A. 
Published: June 2015

AbstractCollections of objects such as images are often presented visually in a grid because it is a compact representation that lends itself well for search and exploration. Most grid layouts are sorted using very basic criteria, such as date or filename. In this work we present a method to arrange collections of objects respecting an arbitrary distance measure. Pairwise distances are preserved as much as possible, while still producing the specific target arrangement which may be a 2D grid, the surface of a sphere, a hierarchy, or any other shape. We show that our method can be used for infographics, collection exploration, summarization, data visualization, and even for solving problems such as where to seat family members at a wedding. We present a fast algorithm that can work on large collections and quantitatively evaluate how well distances are preserved.
Comprehensible Video Thumbnails
Authors: Kim Jongdae , Gray Charles , Asente Paul , Collomosse John 
Published: June 2015

AbstractWe present the Comprehensible Video Thumbnail; an automatically generated visual précis that summarizes salient objects and their dynamics within a video clip. Salient moving objects are detected within clips using a novel stochastic sampling technique that identifies, clusters and then tracks regions exhibiting affine motion coherence within the clip. Tracks are analyzed to determine salient instants at which motion and/or appearance changes significantly, and the resulting objects arranged in a stylized composition optimized to reduce visual clutter and enhance understanding of scene content through classification and depiction of motion type and trajectory. The result is an object‐level visual gist of the clip, obtained with full automation and depicting content and motion with greater descriptive power that prior approaches. We demonstrate these benefits through a user study in which the comprehension of our video thumbnails is compared to the state of the art over a wide variety of sports footage.
Layer‐Based Procedural Design of Façades
Authors: Ilčík Martin , Musialski Przemyslaw , Auzinger Thomas , Wimmer Michael 
Published: June 2015

AbstractWe present a novel procedural framework for interactively modeling building façades. Common procedural approaches, such as shape grammars, assume that building façades are organized in a tree structure, while in practice this is often not the case. Consequently, the complexity of their layout description becomes unmanageable for interactive editing. In contrast, we obtain a façade by composing multiple overlapping layers, where each layer contains a single rectilinear grid of façade elements described by two simple generator patterns. This way, the design process becomes more intuitive and the editing effort for complex layouts is significantly reduced. To achieve this, we present a method for the automated merging of different layers in the form of a mixed discrete and continuous optimization problem. Finally, we provide several modeling examples and a comparison to shape grammars in order to highlight the advantages of our method when designing realistic building façades.
Template Assembly for Detailed Urban Reconstruction
Authors: Nan Liangliang , Jiang Caigui , Ghanem Bernard , Wonka Peter 
Published: June 2015

AbstractWe propose a new framework to reconstruct building details by automatically assembling 3D templates on coarse textured building models. In a preprocessing step, we generate an initial coarse model to approximate a point cloud computed using Structure from Motion and Multi View Stereo, and we model a set of 3D templates of facade details. Next, we optimize the initial coarse model to enforce consistency between geometry and appearance (texture images). Then, building details are reconstructed by assembling templates on the textured faces of the coarse model. The 3D templates are automatically chosen and located by our optimization‐based template assembly algorithm that balances image matching and structural regularity. In the results, we demonstrate how our framework can enrich the details of coarse models using various data sets.
Approximating Free‐form Geometry with Height Fields for Manufacturing
Authors: Herholz Philipp , Matusik Wojciech , Alexa Marc 
Published: June 2015

AbstractWe consider the problem of manufacturing free‐form geometry with classical manufacturing techniques, such as mold casting or 3‐axis milling. We determine a set of constraints that are necessary for manufacturability and then decompose and, if necessary, deform the shape to satisfy the constraints per segment. We show that many objects can be generated from a small number of (mold‐)pieces if slight deformations are acceptable. We provide examples of actual molds and the resulting manufactured objects.
Skeleton‐Intrinsic Symmetrization of Shapes
Authors: Zheng Qian , Hao Zhuming , Huang Hui , Xu Kai , Zhang Hao , Cohen‐Or Daniel , Chen Baoquan 
Published: June 2015

AbstractEnhancing the self‐symmetry of a shape is of fundamental aesthetic virtue. In this paper, we are interested in recovering the aesthetics of intrinsic reflection symmetries, where an asymmetric shape is symmetrized while keeping its general pose and perceived dynamics. The key challenge to intrinsic symmetrization is that the input shape has only approximate reflection symmetries, possibly far from perfect. The main premise of our work is that curve skeletons provide a concise and effective shape abstraction for analyzing approximate intrinsic symmetries as well as symmetrization. By measuring intrinsic distances over a curve skeleton for symmetry analysis, symmetrizing the skeleton, and then propagating the symmetrization from skeleton to shape, our approach to shape symmetrization is skeleton‐intrinsic. Specifically, given an input shape and an extracted curve skeleton, we introduce the notion of a backbone as the path in the skeleton graph about which a self‐matching of the input shape is optimal. We define an objective function for the reflective self‐matching and develop an algorithm based on genetic programming to solve the global search problem for the backbone. The extracted backbone then guides the symmetrization of the skeleton, which in turn, guides the symmetrization of the whole shape. We show numerous intrinsic symmetrization results of hand drawn sketches and artist‐modeled or reconstructed 3D shapes, as well as several applications of skeleton‐intrinsic symmetrization of shapes.
Interactive Disassembly Planning for Complex Objects
Authors: Kerbl Bernhard , Kalkofen Denis , Steinberger Markus , Schmalstieg Dieter 
Published: June 2015

AbstractWe present an approach for the automatic generation, interactive exploration and real‐time modification of disassembly procedures for complex, multipartite CAD data sets. In order to lift the performance barriers prohibiting interactive disassembly planning, we run a detailed analysis on the input model to identify recurring part constellations and efficiently determine blocked part motions in parallel on the GPU. Building on the extracted information, we present an interface for computing and editing extensive disassembly sequences in real‐time while considering user‐defined constraints and avoiding unstable configurations. To evaluate the performance of our C++/CUDA implementation, we use a variety of openly available CAD data sets, ranging from simple to highly complex. In contrast to previous approaches, our work enables interactive disassembly planning for objects which consist of several thousand parts and require cascaded translations during part removal.
Content‐Independent Multi‐Spectral Display Using Superimposed Projections
Authors: Li Yuqi , Majumder Aditi , Lu Dongming , Gopi M. 
Published: June 2015

AbstractMany works focus on multi‐spectral capture and analysis, but multi‐spectral display still remains a challenge. Most prior works on multi‐primary displays use ad‐hoc narrow band primaries that assure a larger color gamut, but cannot assure a good spectral reproduction. Content‐dependent spectral analysis is the only way to produce good spectral reproduction, but cannot be applied to general data sets. Wide primaries are better suited for assuring good spectral reproduction due to greater coverage of the spectral range, but have not been explored much. In this paper we explore the use of wide band primaries for accurate spectral reproduction for the first time and present the first content‐independent multi‐spectral display achieved using superimposed projections with modified wide band primaries. We present a content‐independent primary selection method that selects a small set of n primaries from a large set of m candidate primaries where m > n. Our primary selection method chooses primaries with complete coverage of the range of visible wavelength (for good spectral reproduction accuracy), low interdependency (to limit the primaries to a small number) and higher light throughput (for higher light efficiency). Once the primaries are selected, the input values of the different primary channels to generate a desired spectrum are computed using an optimization method that minimizes spectral mismatch while maximizing visual quality. We implement a real prototype of multi‐spectral display consisting of 9‐primaries using three modified conventional 3‐primary projectors, and compare it with a conventional display to demonstrate its superior performance. Experiments show our display is capable of providing large gamut assuring a good visual appearance while displaying any multi‐spectral images at a high spectral accuracy.
Improving Sampling‐based Motion Control
Authors: Liu Libin , Yin KangKang , Guo Baining 
Published: June 2015

AbstractWe address several limitations of the sampling‐based motion control method of Liu et at. [LYvdP* 10]. The key insight is to learn from the past control reconstruction trials through sample distribution adaptation. Coupled with a sliding window scheme for better performance and an averaging method for noise reduction, the improved algorithm can efficiently construct open‐loop controls for long and challenging reference motions in good quality. Our ideas are intuitive and the implementations are simple. We compare the improved algorithm with the original algorithm both qualitatively and quantitatively, and demonstrate the effectiveness of the improved algorithm with a variety of motions ranging from stylized walking and dancing to gymnastic and Martial Arts routines.
SmartAnnotator An Interactive Tool for Annotating Indoor RGBD Images
Authors: Wong Yu‐Shiang , Chu Hung‐Kuo , Mitra Niloy J. 
Published: June 2015

AbstractRGBD images with high quality annotations, both in the form of geometric (i.e., segmentation) and structural (i.e., how do the segments mutually relate in 3D) information, provide valuable priors for a diverse range of applications in scene understanding and image manipulation. While it is now simple to acquire RGBD images, annotating them, automatically or manually, remains challenging. We present SmartAnnotator, an interactive system to facilitate annotating raw RGBD images. The system performs the tedious tasks of grouping pixels, creating potential abstracted cuboids, inferring object interactions in 3D, and generates an ordered list of hypotheses. The user simply has to flip through the suggestions for segment labels, finalize a selection, and the system updates the remaining hypotheses. As annotations are finalized, the process becomes simpler with fewer ambiguities to resolve. Moreover, as more scenes are annotated, the system makes better suggestions based on the structural and geometric priors learned from previous annotation sessions. We test the system on a large number of indoor scenes across different users and experimental settings, validate the results on existing benchmark datasets, and report significant improvements over low‐level annotation alternatives. (Code and benchmark datasets are publicly available on the project page.)
A Dimension‐reduced Pressure Solver for Liquid Simulations
Authors: Ando Ryoichi , Thürey Nils , Wojtan Chris 
Published: June 2015

AbstractThis work presents a method for efficiently simplifying the pressure projection step in a liquid simulation. We first devise a straightforward dimension reduction technique that dramatically reduces the cost of solving the pressure projection. Next, we introduce a novel change of basis that satisfies free‐surface boundary conditions exactly, regardless of the accuracy of the pressure solve. When combined, these ideas greatly reduce the computational complexity of the pressure solve without compromising free surface boundary conditions at the highest level of detail. Our techniques are easy to parallelize, and they effectively eliminate the computational bottleneck for large liquid simulations.
Implicit Formulation for SPH‐based Viscous Fluids
Authors: Takahashi Tetsuya , Dobashi Yoshinori , Fujishiro Issei , Nishita Tomoyuki , Lin Ming C. 
Published: June 2015

AbstractWe propose a stable and efficient particle‐based method for simulating highly viscous fluids that can generate coiling and buckling phenomena and handle variable viscosity. In contrast to previous methods that use explicit integration, our method uses an implicit formulation to improve the robustness of viscosity integration, therefore enabling use of larger time steps and higher viscosities. We use Smoothed Particle Hydrodynamics to solve the full form of viscosity, constructing a sparse linear system with a symmetric positive definite matrix, while exploiting the variational principle that automatically enforces the boundary condition on free surfaces. We also propose a new method for extracting coefficients of the matrix contributed by second‐ring neighbor particles to efficiently solve the linear system using a conjugate gradient solver. Several examples demonstrate the robustness and efficiency of our implicit formulation over previous methods and illustrate the versatility of our method.
Replaceable Substructures for Efficient Part‐Based Modeling
Authors: Liu Han , Vimont Ulysse , Wand Michael , Cani Marie‐Paule , Hahmann Stefanie , Rohmer Damien , Mitra Niloy J. 
Published: June 2015

AbstractA popular mode of shape synthesis involves mixing and matching parts from different objects to form a coherent whole. The key challenge is to efficiently synthesize shape variations that are plausible, both locally and globally. A major obstacle is to assemble the objects with local consistency, i.e., all the connections between parts are valid with no dangling open connections. The combinatorial complexity of this problem limits existing methods in geometric and/or topological variations of the synthesized models. In this work, we introduce replaceable substructures as arrangements of parts that can be interchanged while ensuring boundary consistency. The consistency information is extracted from part labels and connections in the original source models. We present a polynomial time algorithm that discovers such substructures by working on a dual of the original shape graph that encodes inter‐part connectivity. We demonstrate the algorithm on a range of test examples producing plausible shape variations, both from a geometric and from a topological viewpoint.
Photorealistic rendering of mixed reality scenes
Authors: Kronander Joel , Banterle Francesco , Gardner Andrew , Miandji Ehsan , Unger Jonas 
Published: June 2015

AbstractPhoto‐realistic rendering of virtual objects into real scenes is one of the most important research problems in computer graphics. Methods for capture and rendering of mixed reality scenes are driven by a large number of applications, ranging from augmented reality to visual effects and product visualization. Recent developments in computer graphics, computer vision, and imaging technology have enabled a wide range of new mixed reality techniques including methods for advanced image based lighting, capturing spatially varying lighting conditions, and algorithms for seamlessly rendering virtual objects directly into photographs without explicit measurements of the scene lighting. This report gives an overview of the state‐of‐the‐art in this field, and presents a categorization and comparison of current methods. Our in‐depth survey provides a tool for understanding the advantages and disadvantages of each method, and gives an overview of which technique is best suited to a specific problem.
Recent Advances in Facial Appearance Capture
Authors: Klehm Oliver , Rousselle Fabrice , Papas Marios , Bradley Derek , Hery Christophe , Bickel Bernd , Jarosz Wojciech , Beeler Thabo 
Published: June 2015

AbstractFacial appearance capture is now firmly established within academic research and used extensively across various application domains, perhaps most prominently in the entertainment industry through the design of virtual characters in video games and films. While significant progress has occurred over the last two decades, no single survey currently exists that discusses the similarities, differences, and practical considerations of the available appearance capture techniques as applied to human faces. A central difficulty of facial appearance capture is the way light interacts with skin—which has a complex multi‐layered structure—and the interactions that occur below the skin surface can, by definition, only be observed indirectly. In this report, we distinguish between two broad strategies for dealing with this complexity. “Image‐based methods” try to exhaustively capture the exact face appearance under different lighting and viewing conditions, and then render the face through weighted image combinations. “Parametric methods” instead fit the captured reflectance data to some parametric appearance model used during rendering, allowing for a more lightweight and flexible representation but at the cost of potentially increased rendering complexity or inexact reproduction. The goal of this report is to provide an overview that can guide practitioners and researchers in assessing the tradeoffs between current approaches and identifying directions for future advances in facial appearance capture.
CPH: A Compact Representation for Hierarchical Meshes Generated by Primal Refinement
Authors: Untereiner L. , Kraemer P. , Cazier D. , Bechmann D. 
Published: June 2015

AbstractWe present CPH (Compact Primal Hierarchy): a compact representation of the hierarchical connectivity of surface and volume manifold meshes generated through primal subdivision refinements. CPH is consistently defined in several dimensions and supports multiple kinds of tessellations and refinements, whether regular or adaptive. The basic idea is to store only the finest mesh, encoded in a classical monoresolution structure that is enriched with a minimal set of labels. These labels allow traversal of any intermediate level of the mesh concurrently without having to extract it in an additional structure. Our structure allows attributes to be stored on the cells not only on the finest level, but also on any intermediate level. We study the trade‐off between the memory cost of this compact representation and the time complexity of mesh traversals at any resolution level.
Biological follow‐up in amyotrophic lateral sclerosis: decrease in creatinine levels and increase in ferritin levels predict poor prognosis
Authors: Patin F. , Corcia P. , Madji Hounoum B. , Veyrat‐Durebex C. , Respaud E. , Piver E. , Benz‐de Bretagne I. , Vourc'h P. , Andres C. R. , Blasco H. 
Published: June 2015

Background and purposeAmyotrophic lateral sclerosis (ALS) is a fatal disorder of the motor neuron system, with a median survival of 2 to 4 years and a wide variety of prognosis. Thus, there is a critical need for diagnosis and prognosis biomarkers to improve the care of patients in routine practice. In this study, we aimed to determine prognostic value of routine biochemical markers in sporadic ALS (SALS).MethodsWe retrospectively collected clinical and biological data obtained during the systematic routine monitoring of 216 sporadic ALS patients. The main outcomes were disease duration and annual decline of Revised ALS Functional Rating Scale (ALSFRS‐R). Changes to these biological variables over time were assessed, in link with disease progression.ResultsWe found that concentrations of creatinine (P=0.0166) and ferritin (P=0.0306) changed significantly during the progression of ALS. A reduction of creatinine levels and an increase of ferritin levels were associated with disease progression. Multivariate analysis showed that early variation of ferritin was an independent predictive factor of patient survival (P=0.0048).ConclusionChanges to ferritin and creatinine levels with time are associated with ALS progression. This is the first study describing the changes to these biological variables during ALS progression.