bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computer‐Suggested Facial Makeup
Authors: Scherbaum Kristina , Ritschel Tobias , Hullin Matthias , Thormählen Thorsten , Blanz Volker , Seidel Hans‐Peter 
Published: April 2011

AbstractFinding the best makeup for a given human face is an art in its own right. Experienced makeup artists train for years to be skilled enough to propose a best‐fit makeup for an individual. In this work we propose a system that automates this task. We acquired the appearance of 56 human faces, both without and with professional makeup. To this end, we use a controlled‐light setup, which allows to capture detailed facial appearance information, such as diffuse reflectance, normals, subsurface‐scattering, specularity, or glossiness. A 3D morphable face model is used to obtain 3D positional information and to register all faces into a common parameterization. We then define makeup to be the change of facial appearance and use the acquired database to find a mapping from the space of human facial appearance to makeup. Our main application is to use this mapping to suggest the best‐fit makeup for novel faces that are not in the database. Further applications are makeup transfer, automatic rating of makeup, makeup‐training, or makeup‐exaggeration. As our makeup representation captures a change in reflectance and scattering, it allows us to synthesize faces with makeup in novel 3D views and novel lighting with high realism. The effectiveness of our approach is further validated in a user‐study.
Predicted Virtual Soft Shadow Maps with High Quality Filtering
Authors: Shen Li , Guennebaud Gaël , Yang Baoguang , Feng Jieqing 
Published: April 2011

AbstractIn this paper we present a novel image based algorithm to render visually plausible anti‐aliased soft shadows in a robust and efficient manner. To achieve both high visual quality and high performance, it employs an accurate shadow map filtering method which guarantees smooth penumbrae and high quality anisotropic anti‐aliasing of the sharp transitions. Unlike approaches based on pre‐filtering approximations, our approach does not suffer from light bleeding or losing contact shadows. Discretization artefacts are avoided by creating virtual shadow maps on the fly according to a novel shadow map resolution prediction model. This model takes into account the screen space frequency of the penumbrae via a perceptual metric which has been directly established from an appropriate user study. Consequently, our algorithm always generates shadow maps with minimal resolutions enabling high performance while guarantying high quality. Thanks to this perceptual model, our algorithm can sometimes be faster at rendering soft shadows than hard shadows. It can render game‐like scenes at very high frame rates, and extremely large and complex scenes such as CAD models at interactive rates. In addition, our algorithm is highly scalable, and the quality versus performance trade‐off can be easily tweaked.
Goal‐based Caustics
Authors: Papas Marios , Jarosz Wojciech , Jakob Wenzel , Rusinkiewicz Szymon , Matusik Wojciech , Weyrich Tim 
Published: April 2011

AbstractWe propose a novel system for designing and manufacturing surfaces that produce desired caustic images when illuminated by a light source. Our system is based on a nonnegative image decomposition using a set of possibly overlapping anisotropic Gaussian kernels. We utilize this decomposition to construct an array of continuous surface patches, each of which focuses light onto one of the Gaussian kernels, either through refraction or reflection. We show how to derive the shape of each continuous patch and arrange them by performing a discrete assignment of patches to kernels in the desired caustic. Our decomposition provides for high fidelity reconstruction of natural images using a small collection of patches. We demonstrate our approach on a wide variety of caustic images by manufacturing physical surfaces with a small number of patches.
Estimating Color and Texture Parameters for Vector Graphics
Authors: Jeschke S. , Cline D. , Wonka P. 
Published: April 2011

Abstract Diffusion curves are a powerful vector graphic representation that stores an image as a set of 2D Bezier curves with colors defined on either side. These colors are diffused over the image plane, resulting in smooth color regions as well as sharp boundaries. In this paper, we introduce a new automatic diffusion curve coloring algorithm. We start by defining a geometric heuristic for the maximum density of color control points along the image curves. Following this, we present a new algorithm to set the colors of these points so that the resulting diffused image is as close as possible to a source image in a least squares sense. We compare our coloring solution to the existing one which fails for textured regions, small features, and inaccurately placed curves. The second contribution of the paper is to extend the diffusion curve representation to include texture details based on Gabor noise. Like the curves themselves, the defined texture is resolution independent, and represented compactly. We define methods to automatically make an initial guess for the noise texure, and we provide intuitive manual controls to edit the parameters of the Gabor noise. Finally, we show that the diffusion curve representation itself extends to storing any number of attributes in an image, and we demonstrate this functionality with image stippling an hatching applications.
Hatching for Motion Picture Production
Authors: Umenhoffer Tamás , Szécsi László , Szirmay‐Kalos László 
Published: April 2011

AbstractThis paper presents a hatching algorithm which – while also allows for an implementation in real‐time – is integrated into the production pipeline of computer generated motion picture. Motion picture production pipelines impose special functional and quality requirements. From the functional point of view, the stages of modeling, 3D rendering, and compositing form a pipeline without feed‐back, and frames are rendered independently, possibly on different computers. Thus, no temporal data can be shared between them while flicker free animation needs to be generated. Quality requirements can be grasped as that of dual consistency: the generated hatching must consistently follow object movement and deformation, and, at the same time, it should have a consistent pattern and density in image‐space to provide the hand‐crafted look. In order to meet both requirements, we apply a particle based method and develop an image‐space density control mechanism using rejection sampling and low‐discrepancy sequences. We also discuss the decomposition of rendering tasks according to the main stages of the production pipeline and demonstrate how the artist can define the illustration style in a convenient way.
Symmetry Hierarchy of Man‐Made Objects
Authors: Wang Y. , Xu K. , Li J. , Zhang H. , Shamir A. , Liu L. , Cheng Z. , Xiong Y. 
Published: April 2011

AbstractWe introduce symmetry hierarchy of man‐made objects, a high‐level structural representation of a 3D model providing a symmetry‐induced, hierarchical organization of the model's constituent parts. Given an input mesh, we segment it into primitive parts and build an initial graph which encodes inter‐part symmetries and connectivity relations, as well as self‐symmetries in individual parts. The symmetry hierarchy is constructed from the initial graph via recursive graph contraction which either groups parts by symmetry or assembles connected sets of parts. The order of graph contraction is dictated by a set of precedence rules designed primarily to respect the law of symmetry in perceptual grouping and the principle of compactness of representation. We show that symmetry hierarchy naturally implies a hierarchical segmentation that is more meaningful than those produced by local geometric considerations. We also develop an application of symmetry hierarchies for structural shape editing.
Wavelet Rasterization
Authors: Manson J. , Schaefer S. 
Published: April 2011

AbstractWe present a method for analytically calculating an anti‐aliased rasterization of arbitrary polygons or fonts bounded by Bézier curves in 2D as well as oriented triangle meshes in 3D. Our algorithm rasterizes multiple resolutions simultaneously using a hierarchical wavelet representation and is robust to degenerate inputs. We show that using the simplest wavelet, the Haar basis, is equivalent to performing a box‐filter to the rasterized image. Because we evaluate wavelet coefficients through line integrals in 2D, we are able to derive analytic solutions for polygons that have Bézier curve boundaries of any order, and we provide solutions for quadratic and cubic curves. In 3D, we compute the wavelet coefficients through analytic surface integrals over triangle meshes and show how to do so in a computationally efficient manner.
Comprehensive Facial Performance Capture
Authors: Fyffe Graham , Hawkins Tim , Watts Chris , Ma Wan‐Chun , Debevec Paul 
Published: April 2011

AbstractWe present a system for recording a live dynamic facial performance, capturing highly detailed geometry and spatially varying diffuse and specular reflectance information for each frame of the performance. The result is a reproduction of the performance that can be rendered from novel viewpoints and novel lighting conditions, achieving photorealistic integration into any virtual environment. Dynamic performances are captured directly, without the need for any template geometry or static geometry scans, and processing is completely automatic, requiring no human input or guidance. Our key contributions are a heuristic for estimating facial reflectance information from gradient illumination photographs, and a geometry optimization framework that maximizes a principled likelihood function combining multi‐view stereo correspondence and photometric stereo, using multi‐resolution belief propagation. The output of our system is a sequence of geometries and reflectance maps, suitable for rendering in off‐the‐shelf software. We show results from our system rendered under novel viewpoints and lighting conditions, and validate our results by demonstrating a close match to ground truth photographs.
Deformable Motion: Squeezing into Cluttered Environments
Authors: Choi Myung Geol , Kim Manmyung , Hyun Kyung Lyul , Lee Jehee 
Published: April 2011

AbstractWe present an interactive method that allows animated characters to navigate through cluttered environments. Our characters are equipped with a variety of motion skills to clear obstacles, narrow passages, and highly constrained environment features. Our control method incorporates a behavior model into well‐known, standard path planning algorithms. Our behavior model, called deformable motion, consists of a graph of motion capture fragments. The key idea of our approach is to add flexibility on motion fragments such that we can situate them into a cluttered environment via constraint‐based formulation. We demonstrate our deformable motion for realtime interactive navigation and global path planning in highly constrained virtual environments.
A Sparse Parametric Mixture Model for BTF Compression, Editing and Rendering
Authors: Wu Hongzhi , Dorsey Julie , Rushmeier Holly 
Published: April 2011

AbstractBidirectional texture functions (BTFs) represent the appearance of complex materials. Three major shortcomings with BTFs are the bulky storage, the difficulty in editing and the lack of efficient rendering methods. To reduce storage, many compression techniques have been applied to BTFs, but the results are difficult to edit. To facilitate editing, analytical models have been fit, but at the cost of accuracy of representation for many materials. It becomes even more challenging if efficient rendering is also needed. We introduce a high‐quality general representation that is, at once, compact, easily editable, and can be efficiently rendered. The representation is computed by adopting the stagewise Lasso algorithm to search for a sparse set of analytical functions, whose weighted sum approximates the input appearance data. We achieve compression rates comparable to a state‐of‐the‐art BTF compression method. We also demonstrate results in BTF editing and rendering.
Implicit Brushes for Stylized Line‐based Rendering
Authors: Vergne Romain , Vanderhaeghe David , Chen Jiazhou , Barla Pascal , Granier Xavier , Schlick Christophe 
Published: April 2011

AbstractWe introduce a new technique called Implicit Brushes to render animated 3D scenes with stylized lines in realtime with temporal coherence. An Implicit Brush is defined at a given pixel by the convolution of a brush footprint along a feature skeleton; the skeleton itself is obtained by locating surface features in the pixel neighborhood. Features are identified via image‐space fitting techniques that not only extract their location, but also their profile, which permits to distinguish between sharp and smooth features. Profile parameters are then mapped to stylistic parameters such as brush orientation, size or opacity to give rise to a wide range of line‐based styles.
Prior Knowledge for Part Correspondence
Authors: van Kaick Oliver , Tagliasacchi Andrea , Sidi Oana , Zhang Hao , Cohen‐Or Daniel , Wolf Lior , Hamarneh Ghassan 
Published: April 2011

AbstractClassical approaches to shape correspondence base their computation purely on the properties, in particular geometric similarity, of the shapes in question. Their performance still falls far short of that of humans in challenging cases where corresponding shape parts may differ significantly in geometry or even topology. We stipulate that in these cases, shape correspondence by humans involves recognition of the shape parts where prior knowledge on the parts would play a more dominant role than geometric similarity. We introduce an approach to part correspondence which incorporates prior knowledge imparted by a training set of pre‐segmented, labeled models and combines the knowledge with content‐driven analysis based on geometric similarity between the matched shapes. First, the prior knowledge is learned from the training set in the form of per‐label classifiers. Next, given two query shapes to be matched, we apply the classifiers to assign a probabilistic label to each shape face. Finally, by means of a joint labeling scheme, the probabilistic labels are used synergistically with pairwise assignments derived from geometric similarity to provide the resulting part correspondence. We show that the incorporation of knowledge is especially effective in dealing with shapes exhibiting large intra‐class variations. We also show that combining knowledge and content analyses outperforms approaches guided by either attribute alone.
Walking On Broken Mesh: Defect‐Tolerant Geodesic Distances and Parameterizations
Authors: Campen Marcel , Kobbelt Leif 
Published: April 2011

AbstractEfficient methods to compute intrinsic distances and geodesic paths have been presented for various types of surface representations, most importantly polygon meshes. These meshes are usually assumed to be well‐structured and manifold. In practice, however, they often contain defects like holes, gaps, degeneracies, non‐manifold configurations – or they might even be just a soup of polygons. The task of repairing these defects is computationally complex and in many cases exhibits various ambiguities demanding tedious manual efforts. We present a computational framework that enables the computation of meaningful approximate intrinsic distances and geodesic paths on raw meshes in a way which is tolerant to such defects. Holes and gaps are bridged up to a user‐specified tolerance threshold such that distances can be computed plausibly even across multiple connected components of inconsistent meshes. Further, we show ways to locally parameterize a surface based on geodesic distance fields, easily facilitating the application of textures and decals on raw meshes. We do all this without explicitly repairing the input, thereby avoiding the costly additional efforts. In order to enable broad applicability we provide details on two implementation variants, one optimized for performance, the other optimized for memory efficiency. Using the presented framework many applications can readily be extended to deal with imperfect meshes. Since we abstract from the input applicability is not even limited to meshes, other representations can be handled as well.
Information Shocks and the Dynamics of the Housing Market*
Authors: Fiva Jon H. , Kirkebøen Lars J. 
Published: April 2011

AbstractIn this paper, we analyze housing‐market reactions to the release of previously unpublished information on school quality. Using high‐quality housing data, which precisely bracket the timing of the information shock, we investigate housing‐price dynamics within school‐catchment areas. We find a robust short‐term housing‐market reaction to the publication of school‐quality indicators, suggesting that this information was new to the households, and that households are willing to pay for better schools. The publication effect does not seem to be permanent as prices revert to pre‐publication levels after two to three months.
On application of input data partitioning to Bayesian weighted averaging of biomedical signals
Authors: Momot Alina 
Published: April 2011

AbstractAveraging in the time domain may be used for noise attenuation in case of biomedical signals with a quasi‐cyclical character. Traditional arithmetic averaging technique assumes the constancy of the noise power cycle‐wise, however, most types of noise are not stationary and the variability of noise power is observed. It constitutes a motivation for using methods of weighted averaging, in particular Bayesian weighted averaging. This paper presents the computational study of Bayesian weighted averaging with traditional (sharp) and fuzzy partition of the input data in the presence of non‐stationary noise. There is presented the known empirical Bayesian weighted averaging method (EBWA), with the parameter p describing the probabilistic model, and its modification NBWA which eliminates the parameter. Both methods can be extended by partitioning of the input data. The performance of presented methods is experimentally evaluated for an analytical signal as well as a real ECG signal and compared with traditional arithmetic averaging method. However, the methods can be applied to any signal with a quasi‐cyclical character. The aim of the paper is to show the influence of the type of partition as well as the number of parts on the quality of the averaged signal.
Heterogeneity in the Speed of Adjustment toward Target Leverage*
Authors: ELSAS RALF , FLORYSIAK DAVID 
Published: April 2011

ABSTRACTEstimating the speed of adjustment toward target leverage using the standard partial adjustment model assumes that all firms within the sample adjust at the same (average) pace. Dynamic capital structure theory predicts heterogeneity in adjustment speed due to firm‐specific adjustment costs. Applying an estimator designed to be unbiased in the context of unbalanced dynamic panel data with a fractional dependent variable (DPF estimator), we conduct an extensive analysis of cross‐sectional heterogeneity in the speed of adjustment of firms. We find evidence for pronounced heterogeneity, where speed of adjustment is the highest for firms with high default risk or expected bankruptcy costs, and if opportunity costs of deviating from a target are high. Our evidence is consistent with the general relevance of the trade‐off theory.
Relationship of chromatic visual‐evoked potentials and the changes of foveal photoreceptor layer in central serous chorioretinopathy patients
Authors: Wu Fang , Yang Yabo , Li Haojun , Vernon Odom J 
Published: April 2011

Citation information: Wu F, Yang Y, Li H & Odom JV. Relationship of chromatic visual‐evoked potentials and the changes of foveal photoreceptor layer in central serous chorioretinopathy patients. Ophthalmic Physiol Opt 2011, 31, 381–388. doi: 10.1111/j.1475‐1313.2011.00839.xAbstractPurpose:  To investigate the relative involvement of chromatic and achromatic visual subsystems in central serous chorioretinopathy, and to correlate the function changes with the changes of the foveal photoreceptor layer using Fourier domain optical coherence tomography (FD‐OCT).Methods:  Central serous chorioretinopathy patients and control subjects were tested and compared. Equiluminant Chromatic sinusoidal gratings were presented in a pattern onset‐offset mode. We measured the distance between the internal limiting membrane (ILM) and the external limiting membrane (ELM) on FD‐OCT images.Results:  Visual evoked potential mean latency was delayed significantly in central serous chorioretinopathy patients compared to controls. The visual evoked potential delay was greater for chromatic than for achromatic stimuli. Retinal thickness from ILM to ELM was associated significantly and selectively with short‐wavelength‐sensitive (S) cone visual evoked potential latency (r = −0.40, p = 0.032).Conclusions:  These results are consistent with data that indicate the loss of photoreceptors in central serous chorioretinopathy resulting in a reduced thickness of the outer nuclear layer. Additionally, they are consistent with data which indicate that the photoreceptor loss is relatively greater in cones. The S‐cone pathway was affected the most.
A national survey of diagnostic tests reported by UK community optometrists for the detection of chronic open angle glaucoma
Authors: Myint Joy , Edgar David F , Kotecha Aachal , Murdoch Ian E , Lawrenson John G 
Published: April 2011

Citation information: Myint J, Edgar DF, Kotecha A, Murdoch IE & Lawrenson JG. A national survey of diagnostic tests reported by UK community optometrists for the detection of chronic open angle glaucoma. Ophthalmic Physiol Opt 2011, 31, 353–359. doi: 10.1111/j.1475‐1313.2011.00844.xAbstractPurpose:  In the UK, the majority of cases of chronic open angle glaucoma are detected by community optometrists following a routine sight test. However, there is potential for variability in case finding strategies used. The aim of this study was to carry out a national web‐based survey to determine current diagnostic tests used by optometrists in glaucoma case finding.Methods:  Optometrists on the Association of Optometrists (AOP) electronic database were invited to participate. The survey was open for 16 weeks between April and July 2008.Results:  A total of 1875 optometrists were eligible to enter the survey, of which 1264 answered the questions relating to diagnostic equipment. Respondents were asked to indicate their usual method of examining the optic nerve head. Direct ophthalmoscopy only was used by 25% with the majority (62%) using a combination of direct and slit‐lamp binocular indirect methods. The vast majority of optometrists (78%) used non‐contact tonometry to measure intraocular pressure, with only 16% routinely using a Goldmann or Perkins applanation tonometer. The perimeter most frequently used was either one of the Henson range of instruments (39%) or the Humphrey Field Analyser (22%). A smaller number of optometrists (<5%) had access to more specialised imaging equipment, such as HRT, GDx or OCT.Conclusions:  The results of the survey demonstrate that UK optometrists are well equipped to carry out case finding for chronic open angle glaucoma, although there is a lack of standardisation with respect to equipment used.