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Item Liquid Penetration Modeling for Cloth Dyeing(The Eurographics Association, 2007) Morimoto, Yuki; Tsuruno, Reiji; Tomimatsu, Kiyoshi; Douglas W. Cunningham and Gary Meyer and Laszlo NeumannThis paper presents a model of cloth dyeing using the characteristics of the thread and weave pattern. The proposed dyeing model is based on Fick s second law that defines the molecular transfer under translational diffusion [Fic85]. The algorithm in the proposed model calculates the dyeing distribution from parameters such as the amount of dyeing, saturated amount, and pressure in each cell on a timeline. We improve the algorithm based on Fick s second law to consider a woven cloth structure and describe the proposed model of the structure of woven cloth as a two-layer cellular model. We then visualize the cloth using a simple 2D shading method of asperity by using the color distribution on a dyed image of real woven cloth. In addition, we provide a method for producing dyeing patterns without dyeing diffusion. The proposed method produces images that capture several of the characteristics of dyeing observed in real dyed cloth.Item Design of Multi-dimensional Transfer Functions Using Dimensional Reduction(The Eurographics Association, 2007) Pinto, Francisco de Moura; Freitas, Carla M. D. S.; K. Museth and T. Moeller and A. YnnermanDirect volume rendering techniques allow visualization of volume data without extracting intermediate geometry. The mapping from voxel attributes to optical properties is performed by transfer functions which, consequently, play a crucial role in building informative images from the data. One-dimensional transfer functions, which are based only on a scalar value per voxel, often do not provide proper visualizations. On the other hand, multidimensional transfer functions can perform more sophisticated data classification, based on vectorial voxel signatures. The transfer function design is a non-trivial and unintuitive task, especially in the multi-dimensional case. In this paper we propose a multi-dimensional transfer function design technique that uses self-organizing maps to perform dimensional reduction. Our approach gives uniform treatment to volume data containing voxel signatures of arbitrary dimension, and allows the use of any type of voxel attribute as part of the voxel signatures.Item Applications of High Precision Imaging Polarimetry(The Eurographics Association, 2008) Neumann, Laszlo; Hegedus, Ramon; Horváth, Gábor; Garcia, Rafael; Douglas W. Cunningham and Victoria Interrante and Paul Brown and Jon McCormackWe propose the use of imaging polarimetry for general photography, which is a relatively young technique allowing the determination of polarized components of the light coming from extended objects or scenes. In this paper high resolution and accurate methods are introduced to determine the two linearly polarized components (Q;U) of light. The CIE Luv color space is used in this work to visualize the triplet of (I;Q;U) polarization image components. The structure of this color space is also highly appropriate to represent other attributes of linearly polarized light, such as the polarized intensity, degree and the angle of polarization. The accurately measured polarization components can also be efficiently used for image enhancement. In this direction, a new, polarization-based de-reflection method is proposed. This method is an optimal pixel-wise extension of the widely used photographical polarization filtering. Our method is also capable of amplifying the specular effects. Another application is de-hazing, which removes the linearly polarized component of the haze present in natural scenes, and results in a sharp and color-corrected image. Furthermore, the different combinations of visible and infrared polarization channels enable great possibilities in further de-hazing and to create artistic images.Item Meshless Statistical Occlusion Computation(The Eurographics Association, 2012) Fouquet, François; Farrugia, Jean-Philippe; Iehl, Jean-Claude; Dupuy, Jonathan; Andrea Fusiello and Michael WimmerThis paper presents a new method to evaluate visibility from a point cloud by using a meshless statistical representation. The resulting evaluation uses much less memory than previous work while still producing high quality images, making it suitable for memory limited systems. The obtained results are exposed through the evaluation of shadow maps using a point cloud created from range images and are compared to current methods, which rely on mesh reconstruction techniques.Item Out of Core Photon-Mapping for Large Buildings(The Eurographics Association, 2005) Fradin, David; Meneveaux, Daniel; Horna, Sebastien; Kavita Bala and Philip DutreThis paper describes a new scheme for computing out-of-core global illumination in complex indoor scenes using a photon-mapping approach. Our method makes use of a cells-and-portals representation of the environment for preserving memory coherence and storing rays or photons. We have successfully applied our method to various buildings, composed of up to one billion triangles. As shown in the results, our method requires only a few hundred megabytes of memory for tracing more than 1.6 billion photons in large buildings.Item High-Quality Volume Rendering with Resampling in the Frequency Domain(The Eurographics Association, 2005) Artner, Martin; Möller, Torsten; Viola, Ivan; Gröller, Meister E.; Ken Brodlie and David Duke and Ken JoyThis work introduces a volume rendering technique that is conceptually based on the shear-warp factorization. We propose to perform the shear transformation in the frequency domain. Unlike the standard shear-warp algorithm, we allow for arbitrary sampling distances along the viewing rays, independent from the view direction. The accurate scaling of the volume slices is achieved by using the zero padding interpolation property. Finally, a high quality gradient estimation scheme is presented which uses the derivative theorem of the Fourier transform. Experimental results show that the presented method outperforms established algorithms in the quality of the produced images. If the data is sampled above the Nyquist rate the presented method is capable of a perfect reconstruction of the original function.Item General Linear Cameras with Finite Aperture(The Eurographics Association, 2007) Adams, Andrew; Levoy, Marc; Jan Kautz and Sumanta PattanaikA pinhole camera selects a two-dimensional set of rays from the four-dimensional light field. Pinhole cameras are a type of general linear camera, defined as planar 2D slices of the 4D light field. Cameras with finite apertures can be considered as the summation of a collection of pinhole cameras. In the limit they evaluate a two-dimensional integral of the four-dimensional light field. Hence a general linear camera with finite aperture factors the 4D light field into two integrated dimensions and two imaged dimensions. We present a simple framework for representing these slices and integral projections, based on certain eigenspaces in a two-plane parameterization of the light field. Our framework allows for easy analysis of focus and perspective, and it demonstrates their dual nature. Using our framework, we present analogous taxonomies of perspective and focus, placing within them the familiar perspective, orthographic, cross-slit, and bilinear cameras; astigmatic and anastigmatic focus; and several other varieties of perspective and focus.Item A study on textures and their perceptual visual dimensions as application for flexible and effective scientific visualization(The Eurographics Association, 2006) Taponecco, F.; S. Battiato and G. Gallo and F. StancoThe use of textures is fundamental in several areas of Computer Graphics, Computer Vision and Image Processing. In this work, we focus on their main relevant attributes, in order to define and design textures as effective visual representations for use in scientific visualization. We concentrate on the problem of visualizing complex multivariate and multi-dimensional datasets as well as in synthesizing multi-fields and temporal evolution of vectorial datasets visualization. Textures features, such as directionality, color and shape are particularly suited for use in a synthesis algorithm, and they serve as effective seed primitives, which can incorporate many visual dimensions for intuitive and flexible data mapping and encoding. As special application, we propose a level-based visualization approach, with a special focus on systematic layering of information for scientific datasets.Item Goblins by Spheroidal Weathering(The Eurographics Association, 2007) Beardall, Mathew; Farley, Mckay; Ouderkirk, Darius; Smith, Jeremy; Jones, Michael; Egbert, Parris; D. Ebert and S. MerillouHeight map models of terrain are computationally efficient but can not represent terrain with concave surfaces. We present an algorithm for generating sandstone goblins using a simulation of spheroidal weathering. Sandstone goblins are a kind of hoodoo which are characterized by rounded concave shapes. The weathering simulation uses bubbles centered on axis aligned voxels to approximate geometry-dependent effects of spheroidal weathering. We demonstrate that the algorithm, together with appropriate surface textures, produces visually plausible goblins at near interactive speeds for most simulation parameters.Item Methodologies for Connected Structured Idealized Ice Crystal Growth Models(The Eurographics Association, 2011) El-Alem, Yousef; Roberts, Jonathan C.; R. Laramee and I. S. LimIce crystals are beautiful and intricate shapes. Our goal is to create ice crystal and other models with similar structure and render them in three-dimensions. Many of the current algorithms apply complex physics-based simulation algorithms to simulate the crystal growth, most are two-dimensional forms, and importantly they are made up of many disconnected parts (pixels); consequently they cannot be easily stored as a single model. However, our approach is to generate visually appealing 3d structures, rather than accurately model reality, that are geometrically connected together to form one connected model. These idealized structures can be easily stored, manipulated and included with other 3d-models and into virtual environments. This work is part of a larger project, thus in this poster presentation we merely describe several alternative methodologies to achieve this effect.