bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Part‐aware Surface Metric for Shape Analysis
Authors: Liu Rong , Zhang Hao , Shamir Ariel , Cohen‐Or Daniel 
Published: March 2009

AbstractThe notion of parts in a shape plays an important role in many geometry problems, including segmentation, correspondence, recognition, editing, and animation. As the fundamental geometric representation of 3D objects in computer graphics is surface‐based, solutions of many such problems utilize a surface metric, a distance function defined over pairs of points on the surface, to assist shape analysis and understanding. The main contribution of our work is to bring together these two fundamental concepts: shape parts and surface metric. Specifically, we develop a surface metric that is part‐aware. To encode part information at a point on a shape, we model its volumetric context – called the volumetric shape image (VSI) – inside the shape's enclosed volume, to capture relevant visibility information. We then define the part‐aware metric by combining an appropriate VSI distance with geodesic distance and normal variation. We show how the volumetric view on part separation addresses certain limitations of the surface view, which relies on concavity measures over a surface as implied by the well‐known minima rule. We demonstrate how the new metric can be effectively utilized in various applications including mesh segmentation, shape registration, part‐aware sampling and shape retrieval.
Genuinity Signatures: Designing Signatures for Verifying 3D Object Genuinity
Authors: Aliaga Daniel G. , Atallah Mikhail J. 
Published: March 2009

Abstract3D computer graphics models and digitally‐controlled manufacturing have come together to enable the design, visualization, simulation, and automated creation of complex 3D objects. In our work, we propose and implement a framework for designing computer graphics objects and digitally manufacturing them such that no adversary can make imitations or counterfeit copies of the physical object, even if the adversary has a large number of original copies of the object, knowledge of the original object design, and has manufacturing precision that is comparable to or superior to that of the legitimate creator of the object. Our approach is to design and embed a signature on the surface of the object which acts as a certificate of genuinity of the object. The signature is detectable by a signature‐reading device, based on methods in computer graphics and computer vision, which contains some of the secret information that was used when marking the physical object. Further, the compromise of a signature‐reading device by an adversary who is able to extract all its secrets, does not enable the adversary to create counterfeit objects that fool other readers, thereby still enabling reliable copy detection. We implemented a prototype of our scheme end‐to‐end, including the production of the physical object and the genuinity‐testing device.
Arches: a Framework for Modeling Complex Terrains
Authors: Peytavie A. , Galin E. , Grosjean J. , Merillou S. 
Published: March 2009

AbstractIn this paper, we present a framework for representing complex terrains with such features as overhangs, arches and caves and including different materials such as sand and rocks. Our hybrid model combines a volumetric discrete data structure that stores the different materials and an implicit representation for sculpting and reconstructing the surface of the terrain. Complex scenes can be edited and sculpted interactively with high level tools. We also propose an original rock generation technique that enables us to automatically generate complex rocky sceneries with piles of rocks without any computationally demanding physically‐based simulation.
Structure‐Preserving Reshape for Textured Architectural Scenes
Authors: Cabral Marcio , Lefebvre Sylvain , Dachsbacher Carsten , Drettakis George 
Published: March 2009

AbstractModeling large architectural environments is a difficult task due to the intricate nature of these models and the complex dependencies between the structures represented. Moreover, textures are an essential part of architectural models. While the number of geometric primitives is usually relatively low (i.e., many walls are at surfaces), textures actually contain many detailed architectural elements.We present an approach for modeling architectural scenes by reshaping and combining existing textured models, where the manipulation of the geometry and texture are tightly coupled. For geometry, preserving angles such as oor orientation or vertical walls is of key importance. We thus allow the user to interactively modify lengths of edges, while constraining angles. Our texture reshaping solution introduces a measure of directional autosimilarity to focus stretching in areas of stochastic content and to preserve details in such areas.We show results on several challenging models, and show two applications: Building complex road structures from simple initial pieces and creating complex game‐levels from an existing game based on pre‐existing model pieces.
Completion and Reconstruction with Primitive Shapes
Authors: Schnabel Ruwen , Degener Patrick , Klein Reinhard 
Published: March 2009

AbstractWe consider the problem of reconstruction from incomplete point‐clouds. To find a closed mesh the reconstruction is guided by a set of primitive shapes which has been detected on the input point‐cloud (e.g. planes, cylinders etc.). With this guidance we not only continue the surrounding structure into the holes but also synthesize plausible edges and corners from the primitives' intersections. To this end we give a surface energy functional that incorporates the primitive shapes in a guiding vector field. The discretized functional can be minimized with an efficient graph‐cut algorithm. A novel greedy optimization strategy is proposed to minimize the functional under the constraint that surface parts corresponding to a given primitive must be connected. From the primitive shapes our method can also reconstruct an idealized model that is suitable for use in a CAD system.
Heightfield and spatially varying BRDF Reconstruction for Materials with Interreflections
Authors: Ruiters Roland , Klein Reinhard 
Published: March 2009

AbstractPhoto‐realistic reproduction of material appearance from images has widespread use in applications ranging from movies over advertising to virtual prototyping. A common approach to this task is to reconstruct the small scale geometry of the sample and to capture the reflectance properties using spatially varying BRDFs. For this, multi‐view and photometric stereo reconstruction can be used, both of which are limited regarding the amount of either view or light directions and suffer from either low‐ or high‐frequency artifacts, respectively. In this paper, we propose a new algorithm combining both techniques to recover heightfields and spatially varying BRDFs while at the same time overcoming the above mentioned drawbacks. Our main contribution is a novel objective function which allows for the reconstruction of a heightfield and high quality SVBRDF including view dependent effects. Thereby, our method also avoids both low and high frequency artifacts. Additionally, our algorithm takes inter‐reflections into account allowing for the reconstruction of undisturbed representations of the underlying material. In our experiments, including synthetic and real‐world data, we show that our approach is superior to state‐of‐the‐art methods regarding reconstruction error as well as visual impression. Both the reconstructed geometry and the recovered SVBRDF are highly accurate, resulting in a faithful reproduction of the materials characteristic appearance, which is of paramount importance in the context of material rendering.
Wind projection basis for real‐time animation of trees
Authors: Diener Julien , Rodriguez Mathieu , Baboud Lionel , Reveret Lionel 
Published: March 2009

AbstractThis paper presents a real‐time method to animate complex scenes of thousands of trees under a user‐controllable wind load. Firstly, modal analysis is applied to extract the main modes of deformation from the mechanical model of a 3D tree. The novelty of our contribution is to precompute a new basis of the modal stress of the tree under wind load. At runtime, this basis allows to replace the modal projection of the external forces by a direct mapping for any directional wind. We show that this approach can be efficiently implemented on graphics hardware. This modal animation can be simulated at low computation cost even for large scenes containing thousands of trees.
Positional, Metric, and Curvature Control for Constraint‐Based Surface Deformation
Authors: Eigensatz Michael , Pauly Mark 
Published: March 2009

AbstractWe present a geometry processing framework that allows direct manipulation or preservation of positional, metric, and curvature constraints anywhere on the surface of a geometric model. Target values for these properties can be specified point‐wise or as integrated quantities over curves and surface patches embedded in the shape. For example, the user can draw several curves on the surface and specify desired target lengths, manipulate the normal curvature along these curves, or modify the area or principal curvature distribution of arbitrary surface patches. This user input is converted into a set of non‐linear constraints. A global optimization finds the new deformed surface that best satisfies the constraints, while minimizing adaptable measures for metric and curvature distortion that provide explicit control of the deformation semantics. We illustrate how this approach enables flexible surface processing and shape editing operations not available in current systems.
Continuum‐based Strain Limiting
Authors: Thomaszewski Bernhard , Pabst Simon , Straßer Wolfgang 
Published: March 2009

AbstractWe present Continuum‐based Strain Limiting (CSL) – a new method for limiting deformations in physically‐based cloth simulations. Despite recent developments for nearly inextensible materials, the efficient simulation of general biphasic textiles and their anisotropic behavior remains challenging. Many approaches use soft materials and enforce limits on edge elongations, leading to discretization‐dependent behavior. Moreover, they offer no explicit control over shearing and stretching unless specifically aligned meshes are used. Based on a continuum deformation measure, our method allows accurate control over all strain components using individual thresholds. We impose deformation limits element‐wise and cast the problem as a 6×6 system of linear equations. CSL can be combined with any cloth simulator and, as a velocity filter, integrates seamlessly into standard collision handling.
Deblurring by Matching
Authors: Ancuti Cosmin , Ancuti Codruta Orniana , Bekaert Philippe 
Published: March 2009

AbstractRestoration of the photographs damaged by the camera shake is a challenging task that manifested increasing attention in the recent period. Despite of the important progress of the blind deconvolution techniques, due to the ill‐posed nature of the problem, the finest details of the kernel blur cannot be recovered entirely. Moreover, the additional constraints and prior assumptions make these approaches to be relative limited.In this paper we introduce a novel technique that removes the undesired blur artifacts from photographs taken by hand‐held digital cameras. Our approach is based on the observation that in general several consecutive photographs taken by the users share image regions that project the same scene content. Therefore, we took advantage of additional sharp photographs of the same scene. Based on several invariant local feature points, filtered from the given blurred/non‐blurred images, our approach matches the keypoints and estimates the blur kernel using additional statistical constraints.We also present a simple deconvolution technique that preserves edges while minimizing the ringing artifacts in the restored latent image. The experimental results prove that our technique is able to infer accurately the blur kernel while reducing significantly the artifacts of the spoilt images.
Dominant Texture and Diffusion Distance Manifolds
Authors: Lu Jianye , Dorsey Julie , Rushmeier Holly 
Published: March 2009

AbstractTexture synthesis techniques require nearly uniform texture samples, however identifying suitable texture samples in an image requires significant data preprocessing. To eliminate this work, we introduce a fully automatic pipeline to detect dominant texture samples based on a manifold generated using the diffusion distance. We define the characteristics of dominant texture and three different types of outliers that allow us to efficiently identify dominant texture in feature space. We demonstrate how this method enables the analysis/synthesis of a wide range of natural textures. We compare textures synthesized from a sample image, with and without dominant texture detection. We also compare our approach to that of using a texture segmentation technique alone, and to using Euclidean, rather than diffusion, distances between texture features.
Table‐based Alpha Compression
Authors: Wennersten Per , Ström Jacob 
Published: March 2009

AbstractIn this paper we investigate low‐bitrate compression of scalar textures such as alpha maps, down to one or two bits per pixel. We present two new techniques for 4 × 4 blocks, based on the idea from ETC to use index tables. We demonstrate that although the visual quality of the alpha maps is greatly reduced at these low bit rates, the quality of the final rendered images appears to be sufficient for a wide range of applications, thus allowing bandwidth savings of up to 75%. The 2 bpp version improves PSNR with over 2 dB compared to BTC at the same bit rate. The 1 bpp version is, to the best of our knowledge, the first public 1 bpp texture compression algorithm, which makes comparison hard. However, compared to just DXT5‐compressing a subsampled texture, our 1 bpp technique improves PSNR with over 2 dB. Finally, we show that some aspects of the presented algorithms are also useful for the more common bit rate of four bits per pixel, achieving PSNR scores around 1 dB better than DXT5, over a set of test images.
Detecting Symmetries and Curvilinear Arrangements in Vector Art
Authors: Yeh Yi‐Ting , Měch Radomír 
Published: March 2009

AbstractUnderstanding symmetries and arrangements in existing content is the first step towards providing higher level content aware editing capabilities. Such capabilities may include edits that both preserve existing structure as well as synthesize entirely new structures based on the extracted pattern rules. In this paper we show how to detect regular symmetries and arrangement along curved segments in vector art. We determine individual elements in the art by using the transformation similarity for sequences of sample points on the input curves. Then we detect arrangements of those elements along an arbitrary curved path. We can un‐warp the arrangement path to detect symmetries near the path. We introduce novel applications inform of editing elements that are arranged along a curved path. This includes their sliding along the path, changing of their spacing, or their scale. We also allow the user to brush the elements that the system recognized along new paths.
Quality of life in 1000 patients with early relapsing–remitting multiple sclerosis
Authors: Putzki N. , Fischer J. , Gottwald K. , Reifschneider G. , Ries S. , Siever A. , Hoffmann F. , Käfferlein W. , Kausch U. , Liedtke M. , Kirchmeier J. , Gmünd S. , Richter A. , Schicklmaier P. , Niemczyk G. , Wernsdörfer C. , Hartung H. P. ,   for the “Mensch im Mittelpunkt” Study Group
Published: March 2009

Background and purpose:  To examine the quality of life (QoL) in a large cohort of untreated patients with relapsing–remitting multiple sclerosis (RRMS) and to investigate the impact of intramuscular (IM) interferon beta‐1a (IFNß‐1a) treatment.Methods:  Prospective, observational, open‐label, multicentre study conducted in Germany. Untreated patients with RRMS who initiated treatment with IM IFNß‐1a were included and followed for 12 months. QoL was measured using the EQ‐5D questionnaire. Clinical response was assessed by relapse rate and disability (Expanded Disability Status Scale; EDSS).Results:  A total of 1157 patients were included [mean age 37.6 years, median disease duration 13 months, mean relapse rate 1.7 (95%CI: 1.58–1.73), median EDSS score 2.0]. Relapse rate was reduced to 0.6 at 12 months (95%CI: 0.51–0.69, P < 0.0001). EDSS did not change significantly. At baseline, QoL was considerably lower in MS patients compared with the general German population, but was improved after treatment initiation [utilities of EQ‐5D: 0.77 (95%CI: 0.75–0.78) vs. 0.75 (95%CI: 0.74–0.76) at baseline, 95%CI for difference: 0.01–0.03, P = 0.0046]. Higher disease activity and inability to work were negative predictors of QoL. 14.7% of patients were incapable of working for MS‐related reasons.Conclusions:  Quality of life is considerably impaired in early stages of MS. Treatment initiation with IM IFNß attenuates MS disease activity and improves QoL. Inability to work early during the disease is a major challenge for the social security systems.
Development of Doctrine, or Denial? Balthasar's Holy Saturday and Newman's Essay
Authors: PITSTICK ALYSSA 
Published: March 2009

AbstractEdward Oakes generalized Newman's seven tests for doctrinal development as ‘internal logic’ and ‘developmental consistency’. Using this reduction, he claimed Newman's support for Balthasar's theology of Christ's descent into hell. In fairness to Newman and for a more adequate evaluation of Balthasar, I let Newman speak for himself. His norms are applied to both the traditional doctrine and Balthasar's. Since Balthasar's lacks all seven, it follows it is not a development of doctrine, but a corruption. Oakes' other arguments insufficiently counterbalance this deduction, while the traditional doctrine offers insights into the questions of pluralism and the salvation of the non‐baptized.
‘The Cruciality of the Cross’: P.T. Forsyth's Understanding of the Atonement
Authors: LEOW THENG‐HUAT 
Published: March 2009

AbstractThe writings of British Congregationalist theologian Peter Taylor Forsyth (1848–1921), although traversing a wide range of topics, revolve around a clear centre – his understanding of the significance of the death of Christ on the cross. Commentators on his thought have, however, lamented the occasional nature of his writings on this central doctrine of the atonement, and highlighted aspects of his thought which require clarification. This article seeks to respond to these observations by presenting a fairly complete and systematic view of Forsyth's understanding of the atonement, supplementing his explicit statements where necessary by drawing out the implications of his writings. We hope, at the end, to have demonstrated the robustness of Forsyth's treatment of the atonement, especially its ability to integrate the diverse areas of thought traditionally associated with this doctrine.
The growth, reproduction and mortality of an enclosed population of red deer (Cervus elaphus) in north‐west England
Authors: Goldspink C. R. 
Published: March 2009

This paper considers the growth, reproduction and mortality of enclosed (400 years) red deer, Cervus elaphus L. (n= 250–300), in Lyme Park, Cheshire, England. The Park consists of woodland (116 ha), parkland (175 ha) and moorland (244 ha) habitats. It was privately owned until 1946. Culling to control deer numbers was first done in 1975, and these results cover the period 1975–83.Stags and hinds were locally abundant. Densities of hinds varied from 30 km−2 in the park to 77 km−2 on the moor. Three bachelor herds of stags were present but overall the population was dominated by hinds (sex ratio > 3:1). Performance was generally unexceptional for this species in Britain. Growth rates of stags and hinds were especially poor on the moor (to 400 m). Calf to hind ratios were generally low (range 0‐20‐0‐34) but maxima (0.55–0.60) were recorded in woodland sites.Conditions on the moor were severe during the winter due to the poor quality of herbage (Molinia dominated) and a lack of shelter. Calf mortality (1975–83) varied (10–30%) but was particularly high during the cold winters of 1978–79 and 1981–82. Population density and winter food were probably the two principal factors limiting the performance of deer on the moor. By contrast, growth rates of stags and hinds in the park were high. However, calf to hind ratios were surprisingly low (0.15–0.26). No explanation of this anomally was apparent but the effects of ‘stress’ cannot be ruled out. Parkland stags dominated the rut throughout the whole Park because of their superior size and status. Stags from the moor appeared to play no part in the rut.Culling has reduced levels of natural mortality but further improvements in performance are unlikely to be achieved without a reduction in sheep stocks, some improvement in habitat and the provision of shelter. There may, however, be some merit in retaining a high population density in Lyme Park for conservation reasons. Parks provide unique opportunities for studying the behaviour and ecology of red deer. The effects of competition, parental investment and management can be studied without the inconvenience of immigration or emigration. The problems of managing small populations of deer are briefly discussed.
Jaw movements from microwear on the molar teeth of the koala Phascolarctos cinereus
Authors: Young W. G. , Robson S. K. 
Published: March 2009

To study the direction of jaw movements in the koala from wear facets on the molar teeth by scanning electron microscopy, gold coated epoxy resin replicas from the right maxillary and mandibular tooth quadrants were examined from 12 koala skulls. The progressive development and location of facets, the orientation of striae on them and directional data were recorded and transferred from electron micrographs to superimposable transparencies.Polished facets with laterally oriented striations developed on the cristids and cristae progressively into dentine, where Greaves' effect indicated that the direction of the chewing stroke was labiolingual. Polished and pitted facets, aligned and striated in the parasagittal plane, occurred on the smooth interactive enamel surfaces of maxillary and mandibular cusps.Labiolingual transit of the crislids over the cristae, with a slight anteromedial shift, was inferred to be the predominant chewing stroke on the working side with no contralateral balancing contact. A propalinal isognathous movement in which successive cusps made contact was also deduced.Previous concepts of koala chewing and tooth wear were confirmed and amplified, and these may have application to studies of extinct marsupial jaw mechanisms.