Interactive Generation of Realistic Facial Wrinkles from Sketchy Drawings

Synthesizing facial wrinkles has been tackled either by a long process of manual sculpting on 3D models, or using automatic methods that do not allow for user interaction or artistic expression. In this paper, we propose a method that accepts interactive sketchy drawings depicting wrinkle patterns, and synthesizes realistic looking wrinkles on faces. The method inherits the simplicity of sketching, making it possible for artists as well as novice users to generate realistic facial detail very efficiently, allowing fast preview for physical makeup, or aging simulations for fun and professional applications. All strokes are used to infer the wrinkles, retaining the expressiveness of the sketches and realism of the final result at the same time. This is achieved by designing novel multi‐scale statistics tailored to the wrinkle geometry and coupled to the sketch interpretation method. The statistics capture the cross‐sectional profiles of wrinkles at different scales and parts of a face. The strokes are augmented with the statistics extracted from given example face models, and applied to an input face model interactively. The interface gives the user control over the shapes and scales of wrinkles via sketching while adding extra details required for realism automatically.     

Hierarchical Impostors for the Flocking Algorithm in 3D

The availability of powerful and affordable 3D PC graphics boards has made the rendering of rich immersiveenvironments possible at interactive speeds. The scene update rate and the appropriate behaviour of objects withinthe world are central to this immersive feeling. This paper is concerned with the behaviour computations involvedin the flocking algorithm, which has been used extensively to emulate the flocking behaviour of creatures found innature. The main contribution of this paper is a new method for hierarchically combining portions of the flocksinto groups to reduce the cost of the behavioural computation, allowing far larger flocks to be updated in real‐timein the world. ACM CSS: I.3.7 Three‐Dimensional Graphics and Realism—Animation     

Sharing Resources at Nonuniform Access Rates

We introduce DPPr (for ``Dining Philosophers Problem with rates') as a generalization of the heavy-load case of the Dining Philosophers Problem (DPP). In DPPr, processes are required to be scheduled to access shared resources with prespecified relative frequencies. DPPr is an abstraction of resource-sharing problems to which the synchronization of some distributed algorithms for neural-network models and the generation of timing signals in asynchronous digital circuits are related. Two fully distributed, synchronous solutions are given for DPPr in this paper. The first solution employs a reduction to heavy-load DPP and after that a distributed scheduling mechanism that has been used to solve this problem with optimal concurrency. The second solution tackles the DPPr instance directly by operating on a multigraph based on that instance. We conclude by indicating how the two synchronous solutions carry over to the asynchronous case. Received January 1998, and in final form May 5, 2000. Online publication October 13, 2000.     

Realistic Ultrasound Simulation of Complex Surface Models Using Interactive Monte‐Carlo Path Tracing

Ray‐based simulations have been shown to generate impressively realistic ultrasound images in interactive frame rates. Recent efforts used GPU‐based surface raytracing to simulate complex ultrasound interactions such as multiple reflections and refractions. These methods are restricted to perfectly specular reflections (i.e. following only a single reflective/refractive ray), whereas real tissue exhibits roughness of varying degree at tissue interfaces, causing partly diffuse reflections and refractions. Such surface interactions are significantly more complex and can in general not be handled by conventional deterministic raytracing approaches. However, these can be efficiently computed by Monte‐Carlo sampling techniques, where many ray paths are generated with respect to a probability distribution. In this paper, we introduce Monte‐Carlo raytracing for ultrasound simulation. This enables the realistic simulation of ultrasound‐tissue interactions such as soft shadows and fuzzy reflections. We discuss how to properly weight the contribution of each ray path in order to simulate the behaviour of a beamformed ultrasound signal. Tracing many individual rays per transducer element is easily parallelizable on modern GPUs, as opposed to previous approaches based on recursive binary raytracing. We further propose a significant performance optimization based on adaptive sampling.     

Interactive Glossy Reflections using GPU‐based Ray Tracing with Adaptive LOD

We present an interactive GPU‐based algorithm for accurately rendering high‐quality, dynamic glossy reflection effects from both HDR environment maps and local scene objects. Our method uses hardware rasterization to produce primary pixels, and GPU‐based BRDF importance sampling [ [CK07] ] to quickly generate reflected rays. We utilize a fast GPU ray tracer proposed by Carr et al. [ [CHCH06] ] to compute reflection hits. Our main contribution is an adaptive level‐of‐detail (LOD) control algorithm that greatly improves ray tracing performance during reflection shading. Specifically, we use the solid angle represented by each reflected ray to adaptively pick the level of termination in the BVH traversal step during ray tracing. This leads to 2 ～ 3x speedup over an unmodified implementation of [ [CHCH06] ]. Based on the same solid angle measure, we derive a texture filtering formula to reduce reflection aliasing artifacts, taking advantage of hardware MIP mapping. This extends the filtering algorithm presented in [ [CK07] ] from environment mapping to local scene reflection. Using our algorithm, we demonstrate interactive rendering rates for several scenes featuring dynamic lighting and material changes, spatially varying BRDF parameters, and rigid‐body object movement.     

CancerSPACE: An Interactive E‐learning Tool Aimed to Improve Cancer Screening Rates

Aimed to Improve Cancer Screening Rates. Cancer is the second leading cause of death in the United States today. Due to advances in new medical technology, screening devices for many cancers including breast, cervical, and colon cancers, are drastically reducing mortality rates. These technologies are able to detect cancer early, allowing for earlier treatment and a better survival rate. Unfortunately, many people, especially those in low socioeconomic groups, those without health insurance, and minority groups have very low cancer screening rates. As a result of not being screened, these populations face higher rates of cancer. One way to improve cancer screening rates in low income and minority populations is to target the healthcare staff which works with them. CancerSPACE (Simulated Practice and Collaborative Education) is aimed to improve cancer screening education among healthcare professionals in a virtual, interactive, easy to use online simulation presented in a game format. Simulated education, such as this, can be used on an individual basis at times and locations which are convenient for staff members. It also helps the user to retain information, stay engaged with the task at hand, and learn how to apply the information presented into a real clinical environment.     

Method for Calculation of Sky Light Luminance Aiming at an Interactive Architectural Design

Recently, computer graphics are frequently used for both architectural design and visual environmental assessment. Using computer graphics, designers can easily compare the effect of the natural light on their architectural designs under various conditions, such as different times of day, seasons, atmospheric conditions (clear or overcast sky) or building wall materials. In traditional methods of calculating the luminance due to sky light, however, all calculation must be performed from scratch if such conditions undergo change. Therefore, to compare the architectural designs under different conditions, a great deal of time has to be spent on generating the images. This paper proposes a new method of quickly generating images of an outdoor scene, taking into account glossy specular reflection, even if such conditions change. In this method, luminance due to sky light is expressed by a series of basis functions, and basis luminances corresponding to each basis function are precalculated and stored in a compressed form in the preprocess. Once the basis luminances are calculated, the luminance due to sky light can be quickly calculated by the weighted sum of the basis luminances. Several examples of an architectural design demonstrate the usefulness of the proposed method.     

Realistic built-in self-test for static RAMs

The authors present the specification and design of a self-test mechanism for static random-access memories (RAMs). The test algorithm provides excellent fault detection, and its structure is independent of address and data scrambling. The self-test machine generates data backgrounds on chip and is therefore suitable for both bit-oriented and word-oriented SRAMs. It is also suitable for both embedded SRAMs and stand-alone SRAMs, and adapts to boundary-scan environment. Because of the regular and symmetric structure of the test algorithm, the silicon overhead is only 3% for a 16 K synchronous SRAM     

A Testbed for Realistic Image Synthesis

Classical ray-tracing techniques, which have produced the most realistic computer-generated images to date, are being enhanced in this developmental system.     

Realistic Input Models for Geometric Algorithms

Abstract. The traditional worst-case analysis often fails to predict the actual behavior of the running time of geometric algorithms in practical situations. One reason is that worst-case scenarios are often very contrived and do not occur in practice. To avoid this, models are needed that describe the properties that realistic inputs have, so that the analysis can take these properties into account. We try to bring some structure to this emerging research direction. In particular, we present the following results: • We show the relations between various models that have been proposed in the literature. • For several of these models, we give algorithms to compute the model parameter(s) for a given (planar) scene; these algorithms can be used to verify whether a model is appropriate for typical scenes in some application area. • As a case study, we give some experimental results on the appropriateness of some of the models for one particular type of scene often encountered in geographic information systems, namely certain triangulated irregular networks.     

Error Probability Exponent of List Decoding at Low Rates

We prove that the expurgation bound on the error probability exponent for list-of-L decoding is tight at zero rate.     

极低比特率模型基编码方法的研究状况

基于内容的低比特率编码技术是MPEG-4标准的主要特征.模型基编码把图象信号作为一个结构模型来考虑,是一种基于内容的数据压缩形式,可以达到极低的比特率.由于MPEG-4标准的编码系统是开放的,这就为多种算法的出现提供了前提.本文对极低比特率模型基编码方法进行了总结,重点介绍了其中一些在实用前必须解决的问题如3D线框模型、人脸检测、脸部特征提取、运动参数估计等,并对其算法进行了评述和比较.     

Kyrix: Interactive Pan/Zoom Visualizations at Scale

Pan and zoom are basic yet powerful interaction techniques for exploring large datasets. However, existing zoomable UI toolkits such as Pad++ and ZVTM do not provide the backend database support and data‐driven primitives that are necessary for creating large‐scale visualizations. This limitation in existing general‐purpose toolkits has led to many purpose‐built solutions (e.g. Google Maps and ForeCache) that address the issue of scalability but cannot be easily extended to support visualizations beyond their intended data types and usage scenarios. In this paper, we introduce Kyrix to ease the process of creating general and large‐scale web‐based pan/zoom visualizations. Kyrix is an integrated system that provides the developer with a concise and expressive declarative language along with a backend support for performance optimization of large‐scale data. To evaluate the scalability of Kyrix, we conducted a set of benchmarked experiments and show that Kyrix can support high interactivity (with an average latency of 100 ms or below) on pan/zoom visualizations of 100 million data points. We further demonstrate the accessibility of Kyrix through an observational study with 8 developers. Results indicate that developers can quickly learn Kyrix's underlying declarative model to create scalable pan/zoom visualizations. Finally, we provide a gallery of visualizations and show that Kyrix is expressive and flexible in that it can support the developer in creating a wide range of customized visualizations across different application domains and data types.     

Realistic video generation for american sign language

Multimedia Tools and Applications - There are many ways to generate sign language videos, but most of them are based on 3D character modeling. These methods are time-consuming and labor-intensive,...     

一种改进的扫描线真实感图形显示算法

真实感图形显示是计算机图形学的一个重要组成部分。扫描线算法是一种常用的真实感图形显示算法。文章在扫描线直实感图形显示算法基础之上,对其作了一定的改进。对光照模型增加了衰减变化,并使扫描线算法也适用于曲面,提高了真实感的效果。