Collages have been a common form of artistic expression since their first appearance in China around 200 BC. Recently, with the advance of digital cameras and digital image editing tools, collages have gained populari...
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Collages have been a common form of artistic expression since their first appearance in China around 200 BC. Recently, with the advance of digital cameras and digital image editing tools, collages have gained popularity also as a summarization tool. This paper proposes an approach for automating collage construction, which is based on assembling regions of interest of arbitrary shape in a puzzle-like manner. We show that this approach produces collages that are informative, compact, and eye-pleasing. This is obtained by following artistic principles and assembling the extracted cutouts such that their shapes complete each other.
Advanced illumination models can support depth perception. However, for volume rendering, gradient-based shading models are still the standard. This is because the computation of more advanced lighting effects is expe...
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Advanced illumination models can support depth perception. However, for volume rendering, gradient-based shading models are still the standard. This is because the computation of more advanced lighting effects is expensive and thus strongly affects rendering performance. Nevertheless, interactive frame rates are important for both the interactive design of visual representations and the exploration process. An interactive volumetric lighting model simulates scattering and shadowing to generate high-quality images. Compared to gradient-based shading, this model achieves superior image quality and higher frame rates. To evaluate this model, a user study had participants perform depth perception tasks. The study's results indicate that this model can significantly improve depth perception, compared to conventional gradient-based volume shading. Additionally, because this model isn't based on a gradient computation, it's less sensitive to noise and therefore applicable to imaging modalities suffering from a low signal-to-noise ratio, such as magnetic resonance imaging or 3D ultrasound.
To deal with the extent and variety of digital media, researchers are combining multimedia analysis and visual analytics to form the new field of multimedia analytics. This article gives some historical background, di...
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To deal with the extent and variety of digital media, researchers are combining multimedia analysis and visual analytics to form the new field of multimedia analytics. This article gives some historical background, discusses surveys of related research, describes initial multimedia analytics research, and reports on benchmark datasets.
Experience with the Nintendo Wii Remote indicates that it's an imperfect harbinger of a new class of spatially convenient devices. This tutorial presents techniques for using the Wiimote in 3D user interfaces. It ...
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Experience with the Nintendo Wii Remote indicates that it's an imperfect harbinger of a new class of spatially convenient devices. This tutorial presents techniques for using the Wiimote in 3D user interfaces. It discusses the device's strengths and how to compensate for its limitations, with implications for future spatially convenient devices.
This paper presents a framework to build medical training applications by using virtual reality and a tool that helps the class instantiation of this framework. The main purpose is to make easier the building of virtu...
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This paper presents a framework to build medical training applications by using virtual reality and a tool that helps the class instantiation of this framework. The main purpose is to make easier the building of virtual reality applications in the medical training area, considering systems to simulate biopsy exams and make available deformation, collision detection, and stereoscopy functionalities. The instantiation of the classes allows quick implementation of the tools for such a purpose, thus reducing errors and offering low cost due to the use of open source tools. Using the instantiation tool, the process of building applications is fast and easy. Therefore, computer programmers can obtain an initial application and adapt it to their needs. This tool allows the user to include, delete, and edit parameters in the functionalities chosen as well as storing these parameters for future use. In order to verify the efficiency of the framework, some case studies are presented.
This paper presents a novel framework for elliptical weighted average (EWA) surface splatting with time-varying scenes. We extend the theoretical basis of the original framework by replacing the 2D surface reconstruct...
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This paper presents a novel framework for elliptical weighted average (EWA) surface splatting with time-varying scenes. We extend the theoretical basis of the original framework by replacing the 2D surface reconstruction filters by 3D kernels which unify the spatial and temporal component of moving objects. Based on the newly derived mathematical framework we introduce a rendering algorithm that supports the generation of high-quality motion blur for point-based objects using a piecewise linear approximation of the motion. The rendering algorithm applies ellipsoids as rendering primitives which are constructed by extending planar EWA surface splats into the temporal dimension along the instantaneous motion vector. Finally, we present an implementation of the proposed rendering algorithm with approximated occlusion handling using advanced features of modern GPUs and show its capability of producing motion-blurred result images at interactive frame rates.
Flight simulator systems generally use a separate image-generator component. The host is responsible for the positional data updates of the entities and the image generator is responsible for the rendering process. In...
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Flight simulator systems generally use a separate image-generator component. The host is responsible for the positional data updates of the entities and the image generator is responsible for the rendering process. In such systems, the sense of presence is decreased by model flickering. This study presents a method by which the host can minimize model flickering in the image-generator output. The method is based on preexisting algorithms, such as visibility culling and level of detail management of 3D models. The flickering is minimized for the visually important entities at the expense of increasing the flickering of the entities that are out of the user's focus using a new perception-based approach. It is shown through user studies that the new proposed approach increases the participants' sense of presence.
This article presents the results of experiments studying how the pure-parallelism paradigm scales to massive data sets, including 16,000 or more cores on trillion-cell meshes, the largest data sets published to date ...
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This article presents the results of experiments studying how the pure-parallelism paradigm scales to massive data sets, including 16,000 or more cores on trillion-cell meshes, the largest data sets published to date in the visualization literature. The findings on scaling characteristics and bottlenecks contribute to understanding how pure parallelism will perform in the future.
Diffusion theory allows the production of realistic skin renderings. The dipole and multipole models allow for solving challenging diffusion-theory equations efficiently. By using texture-space diffusion, a Gaussian-b...
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Diffusion theory allows the production of realistic skin renderings. The dipole and multipole models allow for solving challenging diffusion-theory equations efficiently. By using texture-space diffusion, a Gaussian-based approximation, and programmable graphics hardware, developers can create real-time, photorealistic skin renderings. Performing this diffusion in screen space offers advantages that make diffusion approximation practical in scenarios such as games, where having the best possible performance is crucial. However, unlike the texture-space counterpart, the screen-space approach can't simulate transmittance of light through thin geometry; it yields unrealistic results in those cases. A new transmittance algorithm turns the screen-space approach into an efficient global solution, capable of simulating both reflectance and transmittance of light through a multilayered skin model. The transmittance calculations are derived from physical equations, which are implemented through simple texture access. The method performs in real time, requiring no additional memory usage and only minimal additional processing power and memory bandwidth. Despite its simplicity, this practical model manages to reproduce the look of images rendered with other techniques (both offline and real time) such as photon mapping or diffusion approximation.
This new GPU-based algorithm can compute ambient occlusion to inexpensively approximate global-illumination effects in real-time systems and games. The algorithm is based on a novel interpretation of ambient occlusion...
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This new GPU-based algorithm can compute ambient occlusion to inexpensively approximate global-illumination effects in real-time systems and games. The algorithm is based on a novel interpretation of ambient occlusion that measures the relative volume of the visible part of the surface's tangent sphere.
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